expression studio 3 - Page 674

can't the asp file system object access shared server paths?

- by sushant

i am using this code to access files and folders. <%@ Language=VBScript %><% option explicit dim sRoot, sDir, sParent, objFSO, objFolder, objFile, objSubFolder, sSize %> <META content="Microsoft Visual Studio 6.0" name=GENERATOR> <% sRoot = "D:Raghu" sDir = Request("Dir") sDir = sDir & "\" Response.Write "<h1>" & sDir & "</h1>" & vbCRLF Set objFSO = CreateObject("Scripting.FileSystemObject") on error resume next Set objFolder = objFSO.GetFolder(sRoot & sDir) if err.number <> 0 then Response.Write "Could not open folder" Response.End end if on error goto 0 sParent = objFSO.GetParentFolderName(objFolder.Path) ' Remove the contents of sRoot from the front. This gives us the parent ' path relative to the root folder ' eg. if parent folder is "c:webfilessubfolder1subfolder2" then we just want "subfolder1subfolder2" sParent = mid(sParent, len(sRoot) + 1) Response.Write "<table border=""1"">" ' Give a link to the parent folder. This is just a link to this page only pssing in ' the new folder as a parameter Response.Write "<tr><td colspan=3><a href=""browse.asp?dir=" & Server.URLEncode(sParent) & """>Parent folder</a></td></tr>" & vbCRLF ' Now we want to loop through the subfolders in this folder For Each objSubFolder In objFolder.SubFolders ' And provide a link to them Response.Write "<tr><td colspan=3><a href=""browse.asp?dir=" & Server.URLEncode(sDir & objSubFolder.Name) & """>" & objSubFolder.Name & "</a></td></tr>" & vbCRLF Next ' Now we want to loop through the files in this folder For Each objFile In objFolder.Files if Clng(objFile.Size) < 1024 then sSize = objFile.Size & " bytes" else sSize = Clng(objFile.Size / 1024) & " KB" end if ' And provide a link to view them. This is a link to show.asp passing in the directory and the file ' as parameters Response.Write "<tr><td><a href=""show.asp?file=" & server.URLEncode(objFile.Name) & "&dir=" & server.URLEncode (sDir) & """>" & objFile.Name & "</a></td><td>" & sSize & "</td><td>" & objFile.Type & "</td></tr>" & vbCRLF Next Response.Write "</table>" %> it works fine. but when i try to access something on shared path like: "\\cvrdd0110:share" it gives error. how to access these files? and sorry for formatting issues.

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Odd C++ template behaviour with static member vars

- by jon hanson

This piece of code is supposed to calculate an approximation to e (i.e. the mathematical constant ~ 2.71828183) at compile-time, using the following approach; e1 = 2 / 1 e2 = (2 * 2 + 1) / (2 * 1) = 5 / 2 = 2.5 e3 = (3 * 5 + 1) / (3 * 2) = 16 / 6 ~ 2.67 e4 = (4 * 16 + 1) / (4 * 6) = 65 / 24 ~ 2.708 ... e(i) = (e(i-1).numer * i + 1) / (e(i-1).denom * i) The computation is returned via the result static member however, after 2 iterations it yields zero instead of the expected value. I've added a static member function f() to compute the same value and that doesn't exhibit the same problem. #include <iostream> #include <iomanip> // Recursive case. template<int ITERS, int NUMERATOR = 2, int DENOMINATOR = 1, int I = 2> struct CalcE { static const double result; static double f () {return CalcE<ITERS, NUMERATOR * I + 1, DENOMINATOR * I, I + 1>::f ();} }; template<int ITERS, int NUMERATOR, int DENOMINATOR, int I> const double CalcE<ITERS, NUMERATOR, DENOMINATOR, I>::result = CalcE<ITERS, NUMERATOR * I + 1, DENOMINATOR * I, I + 1>::result; // Base case. template<int ITERS, int NUMERATOR, int DENOMINATOR> struct CalcE<ITERS, NUMERATOR, DENOMINATOR, ITERS> { static const double result; static double f () {return result;} }; template<int ITERS, int NUMERATOR, int DENOMINATOR> const double CalcE<ITERS, NUMERATOR, DENOMINATOR, ITERS>::result = static_cast<double>(NUMERATOR) / DENOMINATOR; // Test it. int main (int argc, char* argv[]) { std::cout << std::setprecision (8); std::cout << "e2 ~ " << CalcE<2>::result << std::endl; std::cout << "e3 ~ " << CalcE<3>::result << std::endl; std::cout << "e4 ~ " << CalcE<4>::result << std::endl; std::cout << "e5 ~ " << CalcE<5>::result << std::endl; std::cout << std::endl; std::cout << "e2 ~ " << CalcE<2>::f () << std::endl; std::cout << "e3 ~ " << CalcE<3>::f () << std::endl; std::cout << "e4 ~ " << CalcE<4>::f () << std::endl; std::cout << "e5 ~ " << CalcE<5>::f () << std::endl; return 0; } I've tested this with VS 2008 and VS 2010, and get the same results in each case: e2 ~ 2 e3 ~ 2.5 e4 ~ 0 e5 ~ 0 e2 ~ 2 e3 ~ 2.5 e4 ~ 2.6666667 e5 ~ 2.7083333 Why does result not yield the expected values whereas f() does? According to Rotsor's comment below, this does work with GCC, so I guess the question is, am i relying on some type of undefined behaviour with regards to static initialisation order, or is this a bug with Visual Studio?

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Binding Entity Framework Collections Simply Using ASP.NET MVC

- by jpcmorton

To begin with: Using Entity Framework v4.0. ASP.NET MVC 2.0. Visual Studio 2010. I have a model that consists simply of an order & order items. What I want to do is simply bind that model without too much hassle where possible (avoiding type converters, etc). Simply the model looks like this: public class Order { public int ID { get; set; } public string OrderNumber { get; set; } public EntityCollection<OrderItem> Items { get; set; } } public class OrderItem { public int ID { get; set; } public string Qty { get; set; } } This is as simple as I want to keep it. This model is coming directly from the code generated by the entity framework generator. I would prefer to use the model directly from the entity framework (I know there are views saying this is a bad thing, but alas). I then have the View looking like this: <% using (Html.BeginForm()) {%> <%: Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <div class="editor-label"> <%: Html.LabelFor(model => model.ID) %> </div> <div class="editor-field"> <%: Html.TextBoxFor(model => model.ID) %> <%: Html.ValidationMessageFor(model => model.ID) %> </div> <div class="editor-label"> <%: Html.LabelFor(model => model.OrderNumber) %> </div> <div class="editor-field"> <%: Html.TextBoxFor(model => model.OrderNumber)%> <%: Html.ValidationMessageFor(model => model.OrderNumber)%> </div> <div id="lineItems"> Where I need to put my line items to be edited, inserted </div> <p> <input type="submit" value="Create" /> </p> </fieldset> <% } %> What I want to do is have a situation where I can use dynamic line items (using javascript). Problems are this: How to go about inserting the initial line item (within the lineItems div). This need to be strongly typed and use the built in validation framework of MVC. Best way to go about inserting line items dynamically so that on the postback there is a complete bind to the model without too much messing around (id = 1,2,3,4, etc). Any help, examples, tips, etc would be appreciated.

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Strange performance behaviour for 64 bit modulo operation

- by codymanix

The last three of these method calls take approx. double the time than the first four. The only difference is that their arguments doesn't fit in integer anymore. But should this matter? The parameter is declared to be long, so it should use long for calculation anyway. Does the modulo operation use another algorithm for numbersmaxint? I am using amd athlon64 3200+, winxp sp3 and vs2008. Stopwatch sw = new Stopwatch(); TestLong(sw, int.MaxValue - 3l); TestLong(sw, int.MaxValue - 2l); TestLong(sw, int.MaxValue - 1l); TestLong(sw, int.MaxValue); TestLong(sw, int.MaxValue + 1l); TestLong(sw, int.MaxValue + 2l); TestLong(sw, int.MaxValue + 3l); Console.ReadLine(); static void TestLong(Stopwatch sw, long num) { long n = 0; sw.Reset(); sw.Start(); for (long i = 3; i < 20000000; i++) { n += num % i; } sw.Stop(); Console.WriteLine(sw.Elapsed); } EDIT: I now tried the same with C and the issue does not occur here, all modulo operations take the same time, in release and in debug mode with and without optimizations turned on: #include "stdafx.h" #include "time.h" #include "limits.h" static void TestLong(long long num) { long long n = 0; clock_t t = clock(); for (long long i = 3; i < 20000000LL*100; i++) { n += num % i; } printf("%d - %lld\n", clock()-t, n); } int main() { printf("%i %i %i %i\n\n", sizeof (int), sizeof(long), sizeof(long long), sizeof(void*)); TestLong(3); TestLong(10); TestLong(131); TestLong(INT_MAX - 1L); TestLong(UINT_MAX +1LL); TestLong(INT_MAX + 1LL); TestLong(LLONG_MAX-1LL); getchar(); return 0; } EDIT2: Thanks for the great suggestions. I found that both .net and c (in debug as well as in release mode) does't not use atomically cpu instructions to calculate the remainder but they call a function that does. In the c program I could get the name of it which is "_allrem". It also displayed full source comments for this file so I found the information that this algorithm special cases the 32bit divisors instead of dividends which was the case in the .net application. I also found out that the performance of the c program really is only affected by the value of the divisor but not the dividend. Another test showed that the performance of the remainder function in the .net program depends on both the dividend and divisor. BTW: Even simple additions of long long values are calculated by a consecutive add and adc instructions. So even if my processor calls itself 64bit, it really isn't :( EDIT3: I now ran the c app on a windows 7 x64 edition, compiled with visual studio 2010. The funny thing is, the performance behavior stays the same, although now (I checked the assembly source) true 64 bit instructions are used.

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Data Warehouse ETL slow - change primary key in dimension?

- by Jubbles

I have a working MySQL data warehouse that is organized as a star schema and I am using Talend Open Studio for Data Integration 5.1 to create the ETL process. I would like this process to run once per day. I have estimated that one of the dimension tables (dimUser) will have approximately 2 million records and 23 columns. I created a small test ETL process in Talend that worked, but given the amount of data that may need to be updated daily, the current performance will not cut it. It takes the ETL process four minutes to UPDATE or INSERT 100 records to dimUser. If I assumed a linear relationship between the count of records and the amount of time to UPDATE or INSERT, then there is no way the ETL can finish in 3-4 hours (my hope), let alone one day. Since I'm unfamiliar with Java, I wrote the ETL as a Python script and ran into the same problem. Although, I did discover that if I did only INSERT, the process went much faster. I am pretty sure that the bottleneck is caused by the UPDATE statements. The primary key in dimUser is an auto-increment integer. My friend suggested that I scrap this primary key and replace it with a multi-field primary key (in my case, 2-3 fields). Before I rip the test data out of my warehouse and change the schema, can anyone provide suggestions or guidelines related to the design of the data warehouse the ETL process how realistic it is to have an ETL process INSERT or UPDATE a few million records each day will my friend's suggestion significantly help If you need any further information, just let me know and I'll post it. UPDATE - additional information: mysql> describe dimUser; Field Type Null Key Default Extra user_key int(10) unsigned NO PRI NULL auto_increment id_A int(10) unsigned NO NULL id_B int(10) unsigned NO NULL field_4 tinyint(4) unsigned NO 0 field_5 varchar(50) YES NULL city varchar(50) YES NULL state varchar(2) YES NULL country varchar(50) YES NULL zip_code varchar(10) NO 99999 field_10 tinyint(1) NO 0 field_11 tinyint(1) NO 0 field_12 tinyint(1) NO 0 field_13 tinyint(1) NO 1 field_14 tinyint(1) NO 0 field_15 tinyint(1) NO 0 field_16 tinyint(1) NO 0 field_17 tinyint(1) NO 1 field_18 tinyint(1) NO 0 field_19 tinyint(1) NO 0 field_20 tinyint(1) NO 0 create_date datetime NO 2012-01-01 00:00:00 last_update datetime NO 2012-01-01 00:00:00 run_id int(10) unsigned NO 999 I used a surrogate key because I had read that it was good practice. Since, from a business perspective, I want to keep aware of potential fraudulent activity (say for 200 days a user is associated with state X and then the next day they are associated with state Y - they could have moved or their account could have been compromised), so that is why geographic data is kept. The field id_B may have a few distinct values of id_A associated with it, but I am interested in knowing distinct (id_A, id_B) tuples. In the context of this information, my friend suggested that something like (id_A, id_B, zip_code) be the primary key. For the large majority of daily ETL processes (80%), I only expect the following fields to be updated for existing records: field_10 - field_14, last_update, and run_id (this field is a foreign key to my etlLog table and is used for ETL auditing purposes).

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How do you place an Excel Sheet/Workbook onto a C# .NET Winform?

- by incognick

I am trying to create a stand alone application in Visual Studio 2008 C# .Net that will house Excel Workbooks (2007). I am using Office.Interop in order to create the Excel application and I open the workbooks via Workbooks.Open(...). The Interop does not provide any functionality to "move" the workbooks onto a form so I turned to P/Invoke Win32 library. I am able to move the entire excel application onto a WinForm with great success: // pseudo code to give you the idea excel = new Excel.ApplicationClass(); SetParent(excel.Hwnd, form.handle); This allows me to customize the form and control user input. All right click commands and formula editing work properly. Now, the issue I run into is when I want to open two workbooks in two separate forms. I do this by creating two excel application classes and placing each of those in their own form. When I try to reference one workbook to another workbook via =[Book2]Sheet1!A1, for example, it does not update. This is expected as each application is running under its own thread/process. Here are the alternatives I have tried. If you have any suggestions I would be greatly appreciative.(OLE is not an option. VSTO must be available) Create a single application class and move the workbook window into my form. Results: The window moves into my form and displays correctly, however, no right click or left click works on the form and it never gains focus. (I have tried to manually set focus and it does not work either). My guess is, by moving the window outside of the XLDESK application (viewable in Spy++ for Excel Application), the workbook application (EXCEL7) does not receive the correct window messages to gain focus and to behave properly. This leads me to: Move the XLDESK window handle into my form. Results: This allows the workbook to be click-able again but also has an undesired result of moving all child windows into the same form. Create a main excel application that creates workbooks. Create a new excel application for each new window. Move the workbook under the new excel application XLDESK window. Results: This also has the same effect of the 1st option. Unable to click in the workbook. This must mean that the thread that created the workbook is also responsible for the events. Create a windows hook that watches the WndProc procedure. Results: No events watched. The targeted thread must export the hook proc in a DLL export call. Excel does not do this and thus you cannot inject into it's DLL (unless someone can prove me wrong). I am able to watch all threads within my own process but not from an outside process. Excel is created as a separate process. Subclass NativeWindow. Results: Same as #4. After I move the window into my form, all events are captured up until the mouse is directly over the excel sheet making the sheet seem unclickable. One idea I haven't tried yet is just to continually save the excel sheet as the user edits it. This should update all references but I would feel this would cause poor system performance. There will be numerous chart references as well and I'm not sure if this solution would cause problems further down the road. I think in the end, all the workbooks need to be created by the same Excel Application and then moved to get the desired results but I can't seem to find the correct way to move the windows without disabling the user input in the process. Any suggestions?

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C++ copy-construct construct-and-assign question

- by Andy

Blockquote Here is an extract from item 56 of the book "C++ Gotchas": It's not uncommon to see a simple initialization of a Y object written any of three different ways, as if they were equivalent. Y a( 1066 ); Y b = Y(1066); Y c = 1066; In point of fact, all three of these initializations will probably result in the same object code being generated, but they're not equivalent. The initialization of a is known as a direct initialization, and it does precisely what one might expect. The initialization is accomplished through a direct invocation of Y::Y(int). The initializations of b and c are more complex. In fact, they're too complex. These are both copy initializations. In the case of the initialization of b, we're requesting the creation of an anonymous temporary of type Y, initialized with the value 1066. We then use this anonymous temporary as a parameter to the copy constructor for class Y to initialize b. Finally, we call the destructor for the anonymous temporary. To test this, I did a simple class with a data member (program attached at the end) and the results were surprising. It seems that for the case of b, the object was constructed by the copy constructor rather than as suggested in the book. Does anybody know if the language standard has changed or is this simply an optimisation feature of the compiler? I was using Visual Studio 2008. Code sample: #include <iostream> class Widget { std::string name; public: // Constructor Widget(std::string n) { name=n; std::cout << "Constructing Widget " << this->name << std::endl; } // Copy constructor Widget (const Widget& rhs) { std::cout << "Copy constructing Widget from " << rhs.name << std::endl; } // Assignment operator Widget& operator=(const Widget& rhs) { std::cout << "Assigning Widget from " << rhs.name << " to " << this->name << std::endl; return *this; } }; int main(void) { // construct Widget a("a"); // copy construct Widget b(a); // construct and assign Widget c("c"); c = a; // copy construct! Widget d = a; // construct! Widget e = "e"; // construct and assign Widget f = Widget("f"); return 0; } Output: Constructing Widget a Copy constructing Widget from a Constructing Widget c Assigning Widget from a to c Copy constructing Widget from a Constructing Widget e Constructing Widget f Copy constructing Widget from f I was most surprised by the results of constructing d and e.

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StoreGeneratedPattern T4 EntityFramework concern

- by LoganWolfer

Hi everyone, Here's the situation : I use SQL Server 2008 R2, SQL Replication, Visual Studio 2010, EntityFramework 4, C# 4. The course-of-action from our DBA is to use a rowguid column for SQL Replication to work with our setup. These columns need to have a StoreGeneratedPattern property set to Computed on every one of these columns. The problem : Every time the T4 template regenerate our EDMX (ADO.NET Entity Data Model) file (for example, when we update it from our database), I need to go manually in the EDMX XML file to add this property to every one of them. It has to go from this : <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" /> To this : <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" StoreGeneratedPattern="Computed"/> The solution : I'm trying to find a way to customize an ADO.NET EntityObject Generator T4 file to generate a StoreGeneratedPattern="Computed" to every rowguid that I have. I'm fairly new to T4, I only did customization to AddView and AddController T4 templates for ASP.NET MVC 2, like List.tt for example. I've looked through the EF T4 file, and I can't seem to find through this monster where I could do that (and how). My best guess is somewhere in this part of the file, line 544 to 618 of the original ADO.NET EntityObject Generator T4 file : //////// //////// Write PrimitiveType Properties. //////// private void WritePrimitiveTypeProperty(EdmProperty primitiveProperty, CodeGenerationTools code) { MetadataTools ef = new MetadataTools(this); #> /// <summary> /// <#=SummaryComment(primitiveProperty)#> /// </summary><#=LongDescriptionCommentElement(primitiveProperty, 1)#> [EdmScalarPropertyAttribute(EntityKeyProperty=<#=code.CreateLiteral(ef.IsKey(primitiveProperty))#>, IsNullable=<#=code.CreateLiteral(ef.IsNullable(primitiveProperty))#>)] [DataMemberAttribute()] <#=code.SpaceAfter(NewModifier(primitiveProperty))#><#=Accessibility.ForProperty(primitiveProperty)#> <#=code.Escape(primitiveProperty.TypeUsage)#> <#=code.Escape(primitiveProperty)#> { <#=code.SpaceAfter(Accessibility.ForGetter(primitiveProperty))#>get { <#+ if (ef.ClrType(primitiveProperty.TypeUsage) == typeof(byte[])) { #> return StructuralObject.GetValidValue(<#=code.FieldName(primitiveProperty)#>); <#+ } else { #> return <#=code.FieldName(primitiveProperty)#>; <#+ } #> } <#=code.SpaceAfter(Accessibility.ForSetter((primitiveProperty)))#>set { <#+ if (ef.IsKey(primitiveProperty)) { if (ef.ClrType(primitiveProperty.TypeUsage) == typeof(byte[])) { #> if (!StructuralObject.BinaryEquals(<#=code.FieldName(primitiveProperty)#>, value)) <#+ } else { #> if (<#=code.FieldName(primitiveProperty)#> != value) <#+ } #> { <#+ PushIndent(CodeRegion.GetIndent(1)); } #> <#=ChangingMethodName(primitiveProperty)#>(value); ReportPropertyChanging("<#=primitiveProperty.Name#>"); <#=code.FieldName(primitiveProperty)#> = StructuralObject.SetValidValue(value<#=OptionalNullableParameterForSetValidValue(primitiveProperty, code)#>); ReportPropertyChanged("<#=primitiveProperty.Name#>"); <#=ChangedMethodName(primitiveProperty)#>(); <#+ if (ef.IsKey(primitiveProperty)) { PopIndent(); #> } <#+ } #> } } private <#=code.Escape(primitiveProperty.TypeUsage)#> <#=code.FieldName(primitiveProperty)#><#=code.StringBefore(" = ", code.CreateLiteral(primitiveProperty.DefaultValue))#>; partial void <#=ChangingMethodName(primitiveProperty)#>(<#=code.Escape(primitiveProperty.TypeUsage)#> value); partial void <#=ChangedMethodName(primitiveProperty)#>(); <#+ } Any help would be appreciated. Thanks in advance. EDIT : Didn't find answer to this problem yet, if anyone have ideas to automate this, would really be appreciated.

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How to implement this .NET client and PHP server synchronization scenario?

- by pbean

I have a PHP webserver and a .NET mobile application. The .NET application needs data from a database, which is provided (for now) by the php webserver. I'm fairly new to this kind of scenario so I'm not sure what the best practices are. I ran into a couple of problems and I am not certain how to overcome them. For now, I have the following setup. I run a PHP SOAP server which has a couple of operations which simply retrieve data from the database. For this web service I have created a WSDL file. In Visual Studio I added a web reference to my project using the WSDL file and it generated some classes for it. I simply call something like "MyWebService.GetItems();" and I get an array of items in my .NET application, which come straight from the database. Next I also serialize all these retrieved objects to local (permanent) storage. I face a couple of challenges which I don't know how to resolve properly. The idea is for the mobile client to synchronize the data once (at the start of the day), before working, and then use the local storage throughout the day, and synchronize it back at the end of the day. At the moment all data is downloaded through SOAP, and not a subset (only what is needed). How would I know which new information should be sent to the client? Only the server knows what is new, but only the client knows for sure which data it already has. I seem to be doing double work now. The data which is transferred with SOAP basically already are serialized objects. But at the moment I first retrieve all objects through SOAP and the .NET framework automatically deserializes it. Then I serialize all data again myself. It would be more efficient to simply download it to storage, and then deserialize it. The mobile device does not have a lot of memory. In my test data this is not really a problem, but with potentially tenths of thousands of records I can imagine this will become a problem. Currently when I call the SOAP method, it loads all data into memory (as an array) but as described above perhaps it would be better to have it stored into storage directly, and only retrieve from storage the objects that are needed. But how would I store this? An array would serialize to one big XML (or binary) file from which I cannot choose which objects to load. Would I make (possible tenths of thousands) separate files? Also at the end of the day when I want to send the changes back to the server, how would I know which objects to send... since they're not in memory? I hope my troubles are clear and I hope you are able to help me figure out how to implement this the best way. :) Some things are already fixed (like using .NET on the mobile device, using PHP and having a MySQL database server) but other things can most certainly be changed (like using SOAP).

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ComboBox values disappears after selected when objects used for display

- by Gakk

I have a combobox where I want to display objects and have enum values returned. When first opened the combobox displays the items as supposed, but after a value is chosen it seems to disappear from the list. But if the combobox is active I can use the keyboard to navigate up and down between the other values, so they are in the list but only invisible. I have created a little test application to show my problem. When started the application shows the combobox with all the choices (the two first are type of Object, the third is a String): After the blue line is selected and when the combobox is opened again this line is missing: When the line with the text "Green" is selected that line is still showing: If I had chosen the red line the only thing that would still be in the list is the test "Green". I am using .NET Framework 3.5. Any hints or tips to why the elements disappears? Here are all the code needed after starting a blank project in Visual Studio. MainWindow.xaml.cs: using System; using System.Collections.Generic; using System.Diagnostics; namespace Test { public partial class MainWindow { public MainWindow() { InitializeComponent(); } private ColorComboBoxValue _activeColor; public ColorComboBoxValue ActiveColor { get { return _activeColor; } set { _activeColor = value; Debug.WriteLine("ActiveColor: " + _activeColor.Color); } } } public class ColorList : List<ColorComboBoxValue> { } public class ColorComboBoxValue { public Color Color { get; set; } public Object Object { get; set; } } public enum Color { Red, Blue, Green } } MainWindow.xaml: <Window x:Class="Test.MainWindow" x:Name="window" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:System="clr-namespace:System;assembly=mscorlib" xmlns:local="clr-namespace:Test" Title="ComboBoxTest" Height="100" Width="200"> <Window.Resources> <local:ColorList x:Key="ColorList"> <local:ColorComboBoxValue Color="Red"> <local:ColorComboBoxValue.Object> <Path Data="M0,0 L0,30 60,30 60,0 Z" Fill="Red"/> </local:ColorComboBoxValue.Object> </local:ColorComboBoxValue> <local:ColorComboBoxValue Color="Blue"> <local:ColorComboBoxValue.Object> <Path Data="M0,0 L0,30 60,30 60,0 Z" Fill="Blue"/> </local:ColorComboBoxValue.Object> </local:ColorComboBoxValue> <local:ColorComboBoxValue Color="Green"> <local:ColorComboBoxValue.Object> <System:String>Green</System:String> </local:ColorComboBoxValue.Object> </local:ColorComboBoxValue> </local:ColorList> </Window.Resources> <ComboBox ItemsSource="{Binding Source={StaticResource ColorList}}" SelectedItem="{Binding ActiveColor, ElementName=window}"> <ComboBox.ItemTemplate> <DataTemplate> <ContentPresenter Content="{Binding Path=Object}"/> </DataTemplate> </ComboBox.ItemTemplate> </ComboBox> </Window>

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DataGrid : Binding with two different classes with lists ? WPF C#

- by MyRestlessDream

It is my first question on StackOverflow so I hope I am doing nothing wrong ! Sorry if it is the case ! I need some help because I can not find the solution of my problem. Of course I have searched everywhere on the web but I can not find it (can not post the links that I am using because of my low reputation :( ). Moreover, I am new in C# and WPF (and self-learning). I used to work in C++/Qt so I do not know how everything works in WPF. And sorry for my English, I am French. My problem My basic classes are that an Employee can use a computer. The id of the computer and the date of use are stored into the class Connection. I would like to display the list information in a DataGrid and in RowDetailsTemplate like here : http://i.stack.imgur.com/Bvn1z.png So it will do a binding to the Employee class but also to the Connection class with only the last value of the property (here the last value of the list "Computer ID" and the last value of the list "Connection Date" on this last computer). So it is a loop in the different lists. How can I do it ? Is it too much to do ? :( I succeed to get the Employee informations but I do not know how to bind the list of computer. When I am trying, it shows me "(Collection)" so it does not go inside the list :( Summary of Questions How to display/bind a value from a list AND from a different class in a DataGrid ? How to display all the values of a list into the RowDetailsTemplate ? Under Windows 7 and Visual Studio 2010 Pro version. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ EDIT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solution I have used the solution of Stefan Denchev. Here the modification of my class : http://i.stack.imgur.com/Ijx5i.png And the code used: <DataGrid ItemsSource="{Binding}" Name="table"> <DataGrid.Columns> <DataGridTextColumn Header="First Name" Binding="{Binding FirstName}"/> <DataGridTextColumn Header="Last Name" Binding="{Binding LastName}"/> <DataGridTextColumn Header="Gender" Binding="{Binding Gender}"/> <DataGridTextColumn Header="Last computer used" Binding="{Binding LastComputerID}"/> <DataGridTextColumn Header="Last connection date" Binding="{Binding LastDate}"/> </DataGrid.Columns> <DataGrid.RowDetailsTemplate> <DataTemplate> <DataGrid ItemsSource="{Binding ListOfConnection}"> <DataGrid.Columns> <DataGridTextColumn Header="Computer ID" Binding="{Binding ComputerID}"/> <DataGridTemplateColumn> <DataGridTemplateColumn.CellTemplate> <DataTemplate> <ListView ItemsSource="{Binding ListOfDate}"/> </DataTemplate> </DataGridTemplateColumn.CellTemplate> </DataGridTemplateColumn> </DataGrid.Columns> </DataGrid> </DataTemplate> </DataGrid.RowDetailsTemplate> </DataGrid> With in code behind : List<Employee> allEmployees = WorkflowMgr.Instance.AllEmployees; table.DataContext = allEmployees; And it works ! I have tryed to improve my fake example :) Hope it will help to another developer !

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jQuery .find() doesn't return data in IE but does in Firefox and Chrome

- by Steve Hiner

I helped a friend out by doing a little web work for him. Part of what he needed was an easy way to change a couple pieces of text on his site. Rather than having him edit the HTML I decided to provide an XML file with the messages in it and I used jQuery to pull them out of the file and insert them into the page. It works great... In Firefox and Chrome, not so great in IE7. I was hoping one of you could tell me why. I did a fair but of googling but couldn't find what I'm looking for. Here's the XML: <?xml version="1.0" encoding="utf-8" ?> <messages> <message type="HeaderMessage"> This message is put up in the header area. </message> <message type="FooterMessage"> This message is put in the lower left cell. </message> </messages> And here's my jQuery call: <script type="text/javascript"> $(document).ready(function() { $.get('messages.xml', function(d) { //I have confirmed that it gets to here in IE //and it has the xml loaded. //alert(d); gives me a message box with the xml text in it //alert($(d).find('message')); gives me "[object Object]" //alert($(d).find('message')[0]); gives me "undefined" //alert($(d).find('message').Length); gives me "undefined" $(d).find('message').each(function() { //But it never gets to here in IE var $msg = $(this); var type = $msg.attr("type"); var message = $msg.text(); switch (type) { case "HeaderMessage": $("#HeaderMessageDiv").html(message); break; case "FooterMessage": $("#footermessagecell").html(message); break; default: } }); }); }); </script> Is there something I need to do differently in IE? Based on the message box with [object Object] I'm assumed that .find was working in IE but since I can't index into the array with [0] or check it's Length I'm guessing that means .find isn't returning any results. Any reason why that would work perfectly in Firefox and Chrome but fail in IE? I'm a total newbie with jQuery so I hope I haven't just done something stupid. That code above was scraped out of a forum and modified to suit my needs. Since jQuery is cross-platform I figured I wouldn't have to deal with this mess. Edit: I've found that if I load the page in Visual Studio 2008 and run it then it will work in IE. So it turns out it always works when run through the development web server. Now I'm thinking IE just doesn't like doing .find in XML loaded off of my local drive so maybe when this is on an actual web server it will work OK. I have confirmed that it works fine when browsed from a web server. Must be a peculiarity with IE. I'm guessing it's because the web server sets the mime type for the xml data file transfer and without that IE doesn't parse the xml correctly.

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ASP.NET MVC 3 - New Features

- by imran_ku07

Introduction: ASP.NET MVC 3 just released by ASP.NET MVC team which includes some new features, some changes, some improvements and bug fixes. In this article, I will show you the new features of ASP.NET MVC 3. This will help you to get started using the new features of ASP.NET MVC 3. Full details of this announcement is available at Announcing release of ASP.NET MVC 3, IIS Express, SQL CE 4, Web Farm Framework, Orchard, WebMatrix. Description: New Razor View Engine: Razor view engine is one of the most coolest new feature in ASP.NET MVC 3. Razor is speeding things up just a little bit more. It is much smaller and lighter in size. Also it is very easy to learn. You can say ' write less, do more '. You can get start and learn more about Razor at Introducing “Razor” – a new view engine for ASP.NET. Granular Request Validation: Another biggest new feature in ASP.NET MVC 3 is Granular Request Validation. Default request validator will throw an exception when he see < followed by an exclamation(like <!) or < followed by the letters a through z(like <s) or & followed by a pound sign(like &#123) as a part of querystring, posted form, headers and cookie collection. In previous versions of ASP.NET MVC, you can control request validation using ValidateInputAttriubte. In ASP.NET MVC 3 you can control request validation at Model level by annotating your model properties with a new attribute called AllowHtmlAttribute. For details see Granular Request Validation in ASP.NET MVC 3. Sessionless Controller Support: Sessionless Controller is another great new feature in ASP.NET MVC 3. With Sessionless Controller you can easily control your session behavior for controllers. For example, you can make your HomeController's Session as Disabled or ReadOnly, allowing concurrent request execution for single user. For details see Concurrent Requests In ASP.NET MVC and HowTo: Sessionless Controller in MVC3 – what & and why?. Unobtrusive Ajax and Unobtrusive Client Side Validation is Supported: Another cool new feature in ASP.NET MVC 3 is support for Unobtrusive Ajax and Unobtrusive Client Side Validation. This feature allows separation of responsibilities within your web application by separating your html with your script. For details see Unobtrusive Ajax in ASP.NET MVC 3 and Unobtrusive Client Validation in ASP.NET MVC 3. Dependency Resolver: Dependency Resolver is another great feature of ASP.NET MVC 3. It allows you to register a dependency resolver that will be used by the framework. With this approach your application will not become tightly coupled and the dependency will be injected at run time. For details see ASP.NET MVC 3 Service Location. New Helper Methods: ASP.NET MVC 3 includes some helper methods of ASP.NET Web Pages technology that are used for common functionality. These helper methods includes: Chart, Crypto, WebGrid, WebImage and WebMail. For details of these helper methods, please see ASP.NET MVC 3 Release Notes. For using other helper methods of ASP.NET Web Pages see Using ASP.NET Web Pages Helpers in ASP.NET MVC. Child Action Output Caching: ASP.NET MVC 3 also includes another feature called Child Action Output Caching. This allows you to cache only a portion of the response when you are using Html.RenderAction or Html.Action. This cache can be varied by action name, action method signature and action method parameter values. For details see this. RemoteAttribute: ASP.NET MVC 3 allows you to validate a form field by making a remote server call through Ajax. This makes it very easy to perform remote validation at client side and quickly give the feedback to the user. For details see How to: Implement Remote Validation in ASP.NET MVC. CompareAttribute: ASP.NET MVC 3 includes a new validation attribute called CompareAttribute. CompareAttribute allows you to compare the values of two different properties of a model. For details see CompareAttribute in ASP.NET MVC 3. Miscellaneous New Features: ASP.NET MVC 2 includes FormValueProvider, QueryStringValueProvider, RouteDataValueProvider and HttpFileCollectionValueProvider. ASP.NET MVC 3 adds two additional value providers, ChildActionValueProvider and JsonValueProvider(JsonValueProvider is not physically exist). ChildActionValueProvider is used when you issue a child request using Html.Action and/or Html.RenderAction methods, so that your explicit parameter values in Html.Action and/or Html.RenderAction will always take precedence over other value providers. JsonValueProvider is used to model bind JSON data. For details see Sending JSON to an ASP.NET MVC Action Method Argument. In ASP.NET MVC 3, a new property named FileExtensions added to the VirtualPathProviderViewEngine class. This property is used when looking up a view by path (and not by name), so that only views with a file extension contained in the list specified by this new property is considered. For details see VirtualPathProviderViewEngine.FileExtensions Property . ASP.NET MVC 3 installation package also includes the NuGet Package Manager which will be automatically installed when you install ASP.NET MVC 3. NuGet makes it easy to install and update open source libraries and tools in Visual Studio. See this for details. In ASP.NET MVC 2, client side validation will not trigger for overridden model properties. For example, if have you a Model that contains some overridden properties then client side validation will not trigger for overridden properties in ASP.NET MVC 2 but client side validation will work for overridden properties in ASP.NET MVC 3. Client side validation is not supported for StringLengthAttribute.MinimumLength property in ASP.NET MVC 2. In ASP.NET MVC 3 client side validation will work for StringLengthAttribute.MinimumLength property. ASP.NET MVC 3 includes new action results like HttpUnauthorizedResult, HttpNotFoundResult and HttpStatusCodeResult. ASP.NET MVC 3 includes some new overloads of LabelFor and LabelForModel methods. For details see LabelExtensions.LabelForModel and LabelExtensions.LabelFor. In ASP.NET MVC 3, IControllerFactory includes a new method GetControllerSessionBehavior. This method is used to get controller's session behavior. For details see IControllerFactory.GetControllerSessionBehavior Method. In ASP.NET MVC 3, Controller class includes a new property ViewBag which is of type dynamic. This property allows you to access ViewData Dictionary using C # 4.0 dynamic features. For details see ControllerBase.ViewBag Property. ModelMetadata includes a property AdditionalValues which is of type Dictionary. In ASP.NET MVC 3 you can populate this property using AdditionalMetadataAttribute. For details see AdditionalMetadataAttribute Class. In ASP.NET MVC 3 you can also use MvcScaffolding to scaffold your Views and Controller. For details see Scaffold your ASP.NET MVC 3 project with the MvcScaffolding package. If you want to convert your application from ASP.NET MVC 2 to ASP.NET MVC 3 then there is an excellent tool that automatically converts ASP.NET MVC 2 application to ASP.NET MVC 3 application. For details see MVC 3 Project Upgrade Tool. In ASP.NET MVC 2 DisplayAttribute is not supported but in ASP.NET MVC 3 DisplayAttribute will work properly. ASP.NET MVC 3 also support model level validation via the new IValidatableObject interface. ASP.NET MVC 3 includes a new helper method Html.Raw. This helper method allows you to display unencoded HTML. Summary: In this article I showed you the new features of ASP.NET MVC 3. This will help you a lot when you start using ASP MVC 3. I also provide you the links where you can find further details. Hopefully you will enjoy this article too.

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WiX 3 Tutorial: Understanding main WXS and WXI file

- by Mladen Prajdic

In the previous post we’ve taken a look at the WiX solution/project structure and project properties. We’re still playing with our super SuperForm application and today we’ll take a look at the general parts of the main wxs file, SuperForm.wxs, and the wxi include file. For wxs file we’ll just go over the general description of what each part does in the code comments. The more detailed descriptions will be in future posts about features themselves. WXI include file Include files are exactly what their name implies. To include a wxi file into the wxs file you have to put the wxi at the beginning of each .wxs file you wish to include it in. If you’ve ever worked with C++ you can think of the include files as .h files. For example if you include SuperFormVariables.wxi into the SuperForm.wxs, the variables in the wxi won’t be seen in FilesFragment.wxs or RegistryFragment.wxs. You’d have to include it manually into those two wxs files too. For preprocessor variable $(var.VariableName) to be seen by every file in the project you have to include them in the WiX project properties->Build->“Define preprocessor variables” textbox. This is why I’ve chosen not to go this route because in multi developer teams not everyone has the same directory structure and having a single variable would mean each developer would have to checkout the wixproj file to edit the variable. This is pretty much unacceptable by my standards. This is why we’ve added a System Environment variable named SuperFormFilesDir as is shown in the previous Wix Tutorial post. Because the FilesFragment.wxs is autogenerated on every project build we don’t want to change it manually each time by adding the include wxi at the beginning of the file. This way we couldn’t recreate it in each pre-build event. <?xml version="1.0" encoding="utf-8"?><Include>  <?define MajorVersion="1" ?> <?define MinorVersion="0" ?> <?define BuildVersion="0" ?>  <?define Revision="0" ?>  <?define VersionNumber="$(var.MajorVersion).$(var.MinorVersion).$(var.BuildVersion).$(var.Revision)" ?>  <?define UpgradeCode="YOUR-GUID-HERE" ?>  <?define ResourcesDir="$(var.ProjectDir)\Resources" ?>  <?define ExeProcessName="SuperForm.MainApp.exe" ?></Include> For now there’s no way to tell WiX in Visual Studio to have a wxi include file available to the whole project, so you have to include it in each file separately. Only variables set in “Define preprocessor variables” or System Environment variables are accessible to the whole project for now. The main WXS file: SuperForm.wxs We’ll only take a look at the general structure of the main SuperForm.wxs and not its the details. We’ll cover the details in future posts. The code comments should provide plenty info about what each part does in general. Basically there are 5 major parts. The update part, the conditions and actions part, the UI install sequence, the directory structure and the features we want to include. <?xml version="1.0" encoding="UTF-8"?><Wix xmlns="http://schemas.microsoft.com/wix/2006/wi" xmlns:util="http://schemas.microsoft.com/wix/UtilExtension">  <?include $(sys.CURRENTDIR)Includes\SuperFormVariables.wxi ?>  <Product Id="*" Name="!(loc.ProductName) $(var.VersionNumber)" Language="!(loc.LANG)" Version="$(var.VersionNumber)" Manufacturer="!(loc.ManufacturerName)" UpgradeCode="$(var.UpgradeCode)">  <Package InstallerVersion="300" Compressed="yes" InstallScope="perMachine"/> <Media Id="1" Cabinet="media1.cab" EmbedCab="yes" />  <Upgrade Id="$(var.UpgradeCode)"> <UpgradeVersion OnlyDetect="yes" Minimum="$(var.VersionNumber)" IncludeMinimum="no" Property="NEWER_VERSION_FOUND" /> <UpgradeVersion Minimum="0.0.0.0" IncludeMinimum="yes" Maximum="$(var.VersionNumber)" IncludeMaximum="no" Property="OLDER_VERSION_FOUND" /> </Upgrade>  <PropertyRef Id="NETFRAMEWORK35"/>  <Condition Message="!(loc.DotNetFrameworkNeeded)"> <![CDATA[Installed OR NETFRAMEWORK35]]> </Condition> <Condition Message="!(loc.AppNotSupported)"> <![CDATA[Installed OR ((VersionNT >= 501 AND ServicePackLevel >= 2) OR (VersionNT >= 502))]]> </Condition>  <CustomAction Id="NewerVersionFound" Error="!(loc.SuperFormNewerVersionInstalled)" /> <InstallExecuteSequence>  <Custom Action="NewerVersionFound" After="FindRelatedProducts"> <![CDATA[NEWER_VERSION_FOUND]]> </Custom>  <RemoveExistingProducts After="InstallInitialize"/>  <Custom Action="WixCloseApplications" Before="InstallInitialize" /> </InstallExecuteSequence>  <util:CloseApplication Id="CloseSuperForm" CloseMessage="no" Description="!(loc.MustCloseSuperForm)" ElevatedCloseMessage="no" RebootPrompt="no" Target="$(var.ExeProcessName)" />  <UIRef Id="WixUI_InstallDir" /> <UI>  <DialogRef Id="FilesInUse" /> <DialogRef Id="MsiRMFilesInUse" />  </UI>  <Icon Id="SuperFormIcon.ico" SourceFile="$(var.ResourcesDir)\Exclam.ico" /> <Property Id="ARPPRODUCTICON" Value="SuperFormIcon.ico" />   <Directory Id="TARGETDIR" Name="SourceDir"> <Directory Id="ProgramFilesFolder"> <Directory Id="INSTALLLOCATION" Name="!(loc.ProductName)" /> </Directory> </Directory>  <Property Id="WIXUI_INSTALLDIR" Value="INSTALLLOCATION" />  <Feature Id="SuperFormFeature" Title="!(loc.ProductName)" Level="1"> <ComponentGroupRef Id="SuperFormFiles" /> <ComponentRef Id="cmpVersionInRegistry" /> <ComponentRef Id="cmpIsThisUpdateInRegistry" /> </Feature> </Product></Wix> For more info on what certain attributes mean you should look into the WiX Documentation. WiX 3 tutorial by Mladen Prajdic navigation WiX 3 Tutorial: Solution/Project structure and Dev resources WiX 3 Tutorial: Understanding main wxs and wxi file WiX 3 Tutorial: Generating file/directory fragments with Heat.exe

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September 2011 Release of the Ajax Control Toolkit

- by Stephen Walther

I’m happy to announce the release of the September 2011 Ajax Control Toolkit. This release has several important new features including: Date ranges – When using the Calendar extender, you can specify a start and end date and a user can pick only those dates which fall within the specified range. This was the fourth top-voted feature request for the Ajax Control Toolkit at CodePlex. Twitter Control – You can use the new Twitter control to display recent tweets associated with a particular Twitter user or tweets which match a search query. Gravatar Control – You can use the new Gravatar control to display a unique image for each user of your website. Users can upload custom images to the Gravatar.com website or the Gravatar control can display a unique, auto-generated, image for a user. You can download this release this very minute by visiting CodePlex: http://AjaxControlToolkit.CodePlex.com Alternatively, you can execute the following command from the Visual Studio NuGet console: Improvements to the Ajax Control Toolkit Calendar Control The Ajax Control Toolkit Calendar extender control is one of the most heavily used controls from the Ajax Control Toolkit. The developers on the Superexpert team spent the last sprint focusing on improving this control. There are three important changes that we made to the Calendar control: we added support for date ranges, we added support for highlighting today’s date, and we made fixes to several bugs related to time zones and daylight savings. Using Calendar Date Ranges One of the top-voted feature requests for the Ajax Control Toolkit was a request to add support for date ranges to the Calendar control (this was the fourth most voted feature request at CodePlex). With the latest release of the Ajax Control Toolkit, the Calendar extender now supports date ranges. For example, the following page illustrates how you can create a popup calendar which allows a user only to pick dates between March 2, 2009 and May 16, 2009. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="CalendarDateRange.aspx.cs" Inherits="WebApplication1.CalendarDateRange" %> <%@ Register TagPrefix="asp" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <html> <head runat="server"> <title>Calendar Date Range</title> </head> <body> <form id="form1" runat="server"> <asp:ToolkitScriptManager ID="tsm" runat="server" /> <asp:TextBox ID="txtHotelReservationDate" runat="server" /> <asp:CalendarExtender ID="Calendar1" TargetControlID="txtHotelReservationDate" StartDate="3/2/2009" EndDate="5/16/2009" SelectedDate="3/2/2009" runat="server" /> </form> </body> </html> This page contains three controls: an Ajax Control Toolkit ToolkitScriptManager control, a standard ASP.NET TextBox control, and an Ajax Control Toolkit CalendarExtender control. Notice that the Calendar control includes StartDate and EndDate properties which restrict the range of valid dates. The Calendar control shows days, months, and years outside of the valid range as struck out. You cannot select days, months, or years which fall outside of the range. The following video illustrates interacting with the new date range feature: If you want to experiment with a live version of the Ajax Control Toolkit Calendar extender control then you can visit the Calendar Sample Page at the Ajax Control Toolkit Sample Site. Highlighted Today’s Date Another highly requested feature for the Calendar control was support for highlighting today’s date. The Calendar control now highlights the user’s current date regardless of the user’s time zone. Fixes to Time Zone and Daylight Savings Time Bugs We fixed several significant Calendar extender bugs related to time zones and daylight savings time. For example, previously, when you set the Calendar control’s SelectedDate property to the value 1/1/2007 then the selected data would appear as 12/31/2006 or 1/1/2007 or 1/2/2007 depending on the server time zone. For example, if your server time zone was set to Samoa (UTC-11:00), then setting SelectedDate=”1/1/2007” would result in “12/31/2006” being selected in the Calendar. Users of the Calendar extender control found this behavior confusing. After careful consideration, we decided to change the Calendar extender so that it interprets all dates as UTC dates. In other words, if you set StartDate=”1/1/2007” then the Calendar extender parses the date as 1/1/2007 UTC instead of parsing the date according to the server time zone. By interpreting all dates as UTC dates, we avoid all of the reported issues with the SelectedDate property showing the wrong date. Furthermore, when you set the StartDate and EndDate properties, you know that the same StartDate and EndDate will be selected regardless of the time zone associated with the server or associated with the browser. The date 1/1/2007 will always be the date 1/1/2007. The New Twitter Control This release of the Ajax Control Toolkit introduces a new twitter control. You can use the Twitter control to display recent tweets associated with a particular twitter user. You also can use this control to show the results of a twitter search. The following page illustrates how you can use the Twitter control to display recent tweets made by Scott Hanselman: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TwitterProfile.aspx.cs" Inherits="WebApplication1.TwitterProfile" %> <%@ Register TagPrefix="asp" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <html > <head runat="server"> <title>Twitter Profile</title> </head> <body> <form id="form1" runat="server"> <asp:ToolkitScriptManager ID="tsm" runat="server" /> <asp:Twitter ID="Twitter1" ScreenName="shanselman" runat="server" /> </form> </body> </html> This page includes two Ajax Control Toolkit controls: the ToolkitScriptManager control and the Twitter control. The Twitter control is set to display tweets from Scott Hanselman (shanselman): You also can use the Twitter control to display the results of a search query. For example, the following page displays all recent tweets related to the Ajax Control Toolkit: Twitter limits the number of times that you can interact with their API in an hour. Twitter recommends that you cache results on the server (https://dev.twitter.com/docs/rate-limiting). By default, the Twitter control caches results on the server for a duration of 5 minutes. You can modify the cache duration by assigning a value (in seconds) to the Twitter control's CacheDuration property. The Twitter control wraps a standard ASP.NET ListView control. You can customize the appearance of the Twitter control by modifying its LayoutTemplate, StatusTemplate, AlternatingStatusTemplate, and EmptyDataTemplate. To learn more about the new Twitter control, visit the live Twitter Sample Page. The New Gravatar Control The September 2011 release of the Ajax Control Toolkit also includes a new Gravatar control. This control makes it easy to display a unique image for each user of your website. A Gravatar is associated with an email address. You can visit Gravatar.com and upload an image and associate the image with your email address. That way, every website which uses Gravatars (such as the www.ASP.NET website) will display your image next to your name. For example, I visited the Gravatar.com website and associated an image of a Koala Bear with the email address [email protected]. The following page illustrates how you can use the Gravatar control to display the Gravatar image associated with the [email protected] email address: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="GravatarDemo.aspx.cs" Inherits="WebApplication1.GravatarDemo" %> <%@ Register TagPrefix="asp" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <title>Gravatar Demo</title> </head> <body> <form id="form1" runat="server"> <asp:ToolkitScriptManager ID="tsm" runat="server" /> <asp:Gravatar ID="Gravatar1" Email="[email protected]" runat="server" /> </form> </body> </html> The page above simply displays the Gravatar image associated with the [email protected] email address: If a user has not uploaded an image to Gravatar.com then you can auto-generate a unique image for the user from the user email address. The Gravatar control supports four types of auto-generated images: Identicon -- A different geometric pattern is generated for each unrecognized email. MonsterId -- A different image of a monster is generated for each unrecognized email. Wavatar -- A different image of a face is generated for each unrecognized email. Retro -- A different 8-bit arcade-style face is generated for each unrecognized email. For example, there is no Gravatar image associated with the email address [email protected]. The following page displays an auto-generated MonsterId for this email address: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="GravatarMonster.aspx.cs" Inherits="WebApplication1.GravatarMonster" %> <%@ Register TagPrefix="asp" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <title>Gravatar Monster</title> </head> <body> <form id="form1" runat="server"> <asp:ToolkitScriptManager ID="tsm" runat="server" /> <asp:Gravatar ID="Gravatar1" Email="[email protected]" DefaultImageBehavior="MonsterId" runat="server" /> </form> </body> </html> The page above generates the following image automatically from the supplied email address: To learn more about the properties of the new Gravatar control, visit the live Gravatar Sample Page. ASP.NET Connections Talk on the Ajax Control Toolkit If you are interested in learning more about the changes that we are making to the Ajax Control Toolkit then please come to my talk on the Ajax Control Toolkit at the upcoming ASP.NET Connections conference. In the talk, I will present a summary of the changes that we have made to the Ajax Control Toolkit over the last several months and discuss our future plans. Do you have ideas for new Ajax Control Toolkit controls? Ideas for improving the toolkit? Come to my talk – I would love to hear from you. You can register for the ASP.NET Connections conference by visiting the following website: Register for ASP.NET Connections Summary The previous release of the Ajax Control Toolkit – the July 2011 Release – has had over 100,000 downloads. That is a huge number of developers who are working with the Ajax Control Toolkit. We are really excited about the new features which we added to the Ajax Control Toolkit in the latest September sprint. We hope that you find the updated Calender control, the new Twitter control, and the new Gravatar control valuable when building your ASP.NET Web Forms applications.

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Version Assemblies with TFS 2010 Continuous Integration

- by Steve Michelotti

When I first heard that TFS 2010 had moved to Workflow Foundation for Team Build, I was *extremely* skeptical. I’ve loved MSBuild and didn’t quite understand the reasons for this change. In fact, given that I’ve been exclusively using Cruise Control for Continuous Integration (CI) for the last 5+ years of my career, I was skeptical of TFS for CI in general. However, after going through the learning process for TFS 2010 recently, I’m starting to become a believer. I’m also starting to see some of the benefits with Workflow Foundation for the overall processing because it gives you constructs not available in MSBuild such as parallel tasks, better control flow constructs, and a slightly better customization story. The first customization I had to make to the build process was to version the assemblies of my solution. This is not new. In fact, I’d recommend reading Mike Fourie’s well known post on Versioning Code in TFS before you get started. This post describes several foundational aspects of versioning assemblies regardless of your version of TFS. The main points are: 1) don’t use source control operations for your version file, 2) use a schema like <Major>.<Minor>.<IncrementalNumber>.0, and 3) do not keep AssemblyVersion and AssemblyFileVersion in sync. To do this in TFS 2010, the best post I’ve found has been Jim Lamb’s post of building a custom TFS 2010 workflow activity. Overall, this post is excellent but the primary issue I have with it is that the assembly version numbers produced are based in a date and look like this: “2010.5.15.1”. This is definitely not what I want. I want to be able to communicate to the developers and stakeholders that we are producing the “1.1 release” or “1.2 release” – which would have an assembly version number of “1.1.317.0” for example. In this post, I’ll walk through the process of customizing the assembly version number based on this method – customizing the concepts in Lamb’s post to suit my needs. I’ll also be combining this with the concepts of Fourie’s post – particularly with regards to the standards around how to version the assemblies. The first thing I’ll do is add a file called SolutionAssemblyVersionInfo.cs to the root of my solution that looks like this: 1: using System; 2: using System.Reflection; 3: [assembly: AssemblyVersion("1.1.0.0")] 4: [assembly: AssemblyFileVersion("1.1.0.0")] I’ll then add that file as a Visual Studio link file to each project in my solution by right-clicking the project, “Add – Existing Item…” then when I click the SolutionAssemblyVersionInfo.cs file, making sure I “Add As Link”: Now the Solution Explorer will show our file. We can see that it’s a “link” file because of the black arrow in the icon within all our projects. Of course you’ll need to remove the AssemblyVersion and AssemblyFileVersion attributes from the AssemblyInfo.cs files to avoid the duplicate attributes since they now leave in the SolutionAssemblyVersionInfo.cs file. This is an extremely common technique so that all the projects in our solution can be versioned as a unit. At this point, we’re ready to write our custom activity. The primary consideration is that I want the developer and/or tech lead to be able to easily be in control of the Major.Minor and then I want the CI process to add the third number with a unique incremental number. We’ll leave the fourth position always “0” for now – it’s held in reserve in case the day ever comes where we need to do an emergency patch to Production based on a branched version. Writing the Custom Workflow Activity Similar to Lamb’s post, I’m going to write two custom workflow activities. The “outer” activity (a xaml activity) will be pretty straight forward. It will check if the solution version file exists in the solution root and, if so, delegate the replacement of version to the AssemblyVersionInfo activity which is a CodeActivity highlighted in red below: Notice that the arguments of this activity are the “solutionVersionFile” and “tfsBuildNumber” which will be passed in. The tfsBuildNumber passed in will look something like this: “CI_MyApplication.4” and we’ll need to grab the “4” (i.e., the incremental revision number) and put that in the third position. Then we’ll need to honor whatever was specified for Major.Minor in the SolutionAssemblyVersionInfo.cs file. For example, if the SolutionAssemblyVersionInfo.cs file had “1.1.0.0” for the AssemblyVersion (as shown in the first code block near the beginning of this post), then we want to resulting file to have “1.1.4.0”. Before we do anything, let’s put together a unit test for all this so we can know if we get it right: 1: [TestMethod] 2: public void Assembly_version_should_be_parsed_correctly_from_build_name() 3: { 4: // arrange 5: const string versionFile = "SolutionAssemblyVersionInfo.cs"; 6: WriteTestVersionFile(versionFile); 7: var activity = new VersionAssemblies(); 8: var arguments = new Dictionary<string, object> { 9: { "tfsBuildNumber", "CI_MyApplication.4"}, 10: { "solutionVersionFile", versionFile} 11: }; 12: 13: // act 14: var result = WorkflowInvoker.Invoke(activity, arguments); 15: 16: // assert 17: Assert.AreEqual("1.2.4.0", (string)result["newAssemblyFileVersion"]); 18: var lines = File.ReadAllLines(versionFile); 19: Assert.IsTrue(lines.Contains("[assembly: AssemblyVersion(\"1.2.0.0\")]")); 20: Assert.IsTrue(lines.Contains("[assembly: AssemblyFileVersion(\"1.2.4.0\")]")); 21: } 22: 23: private void WriteTestVersionFile(string versionFile) 24: { 25: var fileContents = "using System.Reflection;\n" + 26: "[assembly: AssemblyVersion(\"1.2.0.0\")]\n" + 27: "[assembly: AssemblyFileVersion(\"1.2.0.0\")]"; 28: File.WriteAllText(versionFile, fileContents); 29: } At this point, the code for our AssemblyVersion activity is pretty straight forward: 1: [BuildActivity(HostEnvironmentOption.Agent)] 2: public class AssemblyVersionInfo : CodeActivity 3: { 4: [RequiredArgument] 5: public InArgument<string> FileName { get; set; } 6: 7: [RequiredArgument] 8: public InArgument<string> TfsBuildNumber { get; set; } 9: 10: public OutArgument<string> NewAssemblyFileVersion { get; set; } 11: 12: protected override void Execute(CodeActivityContext context) 13: { 14: var solutionVersionFile = this.FileName.Get(context); 15: 16: // Ensure that the file is writeable 17: var fileAttributes = File.GetAttributes(solutionVersionFile); 18: File.SetAttributes(solutionVersionFile, fileAttributes & ~FileAttributes.ReadOnly); 19: 20: // Prepare assembly versions 21: var majorMinor = GetAssemblyMajorMinorVersionBasedOnExisting(solutionVersionFile); 22: var newBuildNumber = GetNewBuildNumber(this.TfsBuildNumber.Get(context)); 23: var newAssemblyVersion = string.Format("{0}.{1}.0.0", majorMinor.Item1, majorMinor.Item2); 24: var newAssemblyFileVersion = string.Format("{0}.{1}.{2}.0", majorMinor.Item1, majorMinor.Item2, newBuildNumber); 25: this.NewAssemblyFileVersion.Set(context, newAssemblyFileVersion); 26: 27: // Perform the actual replacement 28: var contents = this.GetFileContents(newAssemblyVersion, newAssemblyFileVersion); 29: File.WriteAllText(solutionVersionFile, contents); 30: 31: // Restore the file's original attributes 32: File.SetAttributes(solutionVersionFile, fileAttributes); 33: } 34: 35: #region Private Methods 36: 37: private string GetFileContents(string newAssemblyVersion, string newAssemblyFileVersion) 38: { 39: var cs = new StringBuilder(); 40: cs.AppendLine("using System.Reflection;"); 41: cs.AppendFormat("[assembly: AssemblyVersion(\"{0}\")]", newAssemblyVersion); 42: cs.AppendLine(); 43: cs.AppendFormat("[assembly: AssemblyFileVersion(\"{0}\")]", newAssemblyFileVersion); 44: return cs.ToString(); 45: } 46: 47: private Tuple<string, string> GetAssemblyMajorMinorVersionBasedOnExisting(string filePath) 48: { 49: var lines = File.ReadAllLines(filePath); 50: var versionLine = lines.Where(x => x.Contains("AssemblyVersion")).FirstOrDefault(); 51: 52: if (versionLine == null) 53: { 54: throw new InvalidOperationException("File does not contain [assembly: AssemblyVersion] attribute"); 55: } 56: 57: return ExtractMajorMinor(versionLine); 58: } 59: 60: private static Tuple<string, string> ExtractMajorMinor(string versionLine) 61: { 62: var firstQuote = versionLine.IndexOf('"') + 1; 63: var secondQuote = versionLine.IndexOf('"', firstQuote); 64: var version = versionLine.Substring(firstQuote, secondQuote - firstQuote); 65: var versionParts = version.Split('.'); 66: return new Tuple<string, string>(versionParts[0], versionParts[1]); 67: } 68: 69: private string GetNewBuildNumber(string buildName) 70: { 71: return buildName.Substring(buildName.LastIndexOf(".") + 1); 72: } 73: 74: #endregion 75: } At this point the final step is to incorporate this activity into the overall build template. Make a copy of the DefaultTempate.xaml – we’ll call it DefaultTemplateWithVersioning.xaml. Before the build and labeling happens, drag the VersionAssemblies activity in. Then set the LabelName variable to “BuildDetail.BuildDefinition.Name + "-" + newAssemblyFileVersion since the newAssemblyFileVersion was produced by our activity. Configuring CI Once you add your solution to source control, you can configure CI with the build definition window as shown here. The main difference is that we’ll change the Process tab to reflect a different build number format and choose our custom build process file: When the build completes, we’ll see the name of our project with the unique revision number: If we look at the detailed build log for the latest build, we’ll see the label being created with our custom task: We can now look at the history labels in TFS and see the project name with the labels (the Assignment activity I added to the workflow): Finally, if we look at the physical assemblies that are produced, we can right-click on any assembly in Windows Explorer and see the assembly version in its properties: Full Traceability We now have full traceability for our code. There will never be a question of what code was deployed to Production. You can always see the assembly version in the properties of the physical assembly. That can be traced back to a label in TFS where the unique revision number matches. The label in TFS gives you the complete snapshot of the code in your source control repository at the time the code was built. This type of process for full traceability has been used for many years for CI – in fact, I’ve done similar things with CCNet and SVN for quite some time. This is simply the TFS implementation of that pattern. The new features that TFS 2010 give you to make these types of customizations in your build process are quite easy once you get over the initial curve.

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Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1

- by Bobby Diaz

Update: Live demo and source code now available! The recent wave of earthquakes (no pun intended) being reported in the news got me wondering about the frequency and severity of earthquakes around the world. Since I’ve been doing a lot of Silverlight development lately, I decided to scratch my curiosity with a nice little Bing Maps application that will show the location and relative strength of recent seismic activity. Here is a list of technologies this application will utilize, so be sure to have everything downloaded and installed if you plan on following along. Silverlight 3 WCF RIA Services Bing Maps Silverlight Control * Managed Extensibility Framework (optional) MVVM Light Toolkit (optional) log4net (optional) * If you are new to Bing Maps or have not signed up for a Developer Account, you will need to visit www.bingmapsportal.com to request a Bing Maps key for your application. Getting Started We start out by creating a new Silverlight Application called EarthquakeLocator and specify that we want to automatically create the Web Application Project with RIA Services enabled. I cleaned up the web app by removing the Default.aspx and EarthquakeLocatorTestPage.html. Then I renamed the EarthquakeLocatorTestPage.aspx to Default.aspx and set it as my start page. I also set the development server to use a specific port, as shown below. RIA Services Next, I created a Services folder in the EarthquakeLocator.Web project and added a new Domain Service Class called EarthquakeService.cs. This is the RIA Services Domain Service that will provide earthquake data for our client application. I am not using LINQ to SQL or Entity Framework, so I will use the <empty domain service class> option. We will be pulling data from an external Atom feed, but this example could just as easily pull data from a database or another web service. This is an important distinction to point out because each scenario I just mentioned could potentially use a different Domain Service base class (i.e. LinqToSqlDomainService<TDataContext>). Now we can start adding Query methods to our EarthquakeService that pull data from the USGS web site. Here is the complete code for our service class: using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.ServiceModel.Syndication; using System.Web.DomainServices; using System.Web.Ria; using System.Xml; using log4net; using EarthquakeLocator.Web.Model; namespace EarthquakeLocator.Web.Services { /// <summary> /// Provides earthquake data to client applications. /// </summary> [EnableClientAccess()] public class EarthquakeService : DomainService { private static readonly ILog log = LogManager.GetLogger(typeof(EarthquakeService)); // USGS Data Feeds: http://earthquake.usgs.gov/earthquakes/catalogs/ private const string FeedForPreviousDay = "http://earthquake.usgs.gov/earthquakes/catalogs/1day-M2.5.xml"; private const string FeedForPreviousWeek = "http://earthquake.usgs.gov/earthquakes/catalogs/7day-M2.5.xml"; /// <summary> /// Gets the earthquake data for the previous week. /// </summary> /// <returns>A queryable collection of <see cref="Earthquake"/> objects.</returns> public IQueryable<Earthquake> GetEarthquakes() { var feed = GetFeed(FeedForPreviousWeek); var list = new List<Earthquake>(); if ( feed != null ) { foreach ( var entry in feed.Items ) { var quake = CreateEarthquake(entry); if ( quake != null ) { list.Add(quake); } } } return list.AsQueryable(); } /// <summary> /// Creates an <see cref="Earthquake"/> object for each entry in the Atom feed. /// </summary> /// <param name="entry">The Atom entry.</param> /// <returns></returns> private Earthquake CreateEarthquake(SyndicationItem entry) { Earthquake quake = null; string title = entry.Title.Text; string summary = entry.Summary.Text; string point = GetElementValue<String>(entry, "point"); string depth = GetElementValue<String>(entry, "elev"); string utcTime = null; string localTime = null; string depthDesc = null; double? magnitude = null; double? latitude = null; double? longitude = null; double? depthKm = null; if ( !String.IsNullOrEmpty(title) && title.StartsWith("M") ) { title = title.Substring(2, title.IndexOf(',')-3).Trim(); magnitude = TryParse(title); } if ( !String.IsNullOrEmpty(point) ) { var values = point.Split(' '); if ( values.Length == 2 ) { latitude = TryParse(values[0]); longitude = TryParse(values[1]); } } if ( !String.IsNullOrEmpty(depth) ) { depthKm = TryParse(depth); if ( depthKm != null ) { depthKm = Math.Round((-1 * depthKm.Value) / 100, 2); } } if ( !String.IsNullOrEmpty(summary) ) { summary = summary.Replace("</p>", ""); var values = summary.Split( new string[] { "<p>" }, StringSplitOptions.RemoveEmptyEntries); if ( values.Length == 3 ) { var times = values[1].Split( new string[] { "<br>" }, StringSplitOptions.RemoveEmptyEntries); if ( times.Length > 0 ) { utcTime = times[0]; } if ( times.Length > 1 ) { localTime = times[1]; } depthDesc = values[2]; depthDesc = "Depth: " + depthDesc.Substring(depthDesc.IndexOf(":") + 2); } } if ( latitude != null && longitude != null ) { quake = new Earthquake() { Id = entry.Id, Title = entry.Title.Text, Summary = entry.Summary.Text, Date = entry.LastUpdatedTime.DateTime, Url = entry.Links.Select(l => Path.Combine(l.BaseUri.OriginalString, l.Uri.OriginalString)).FirstOrDefault(), Age = entry.Categories.Where(c => c.Label == "Age") .Select(c => c.Name).FirstOrDefault(), Magnitude = magnitude.GetValueOrDefault(), Latitude = latitude.GetValueOrDefault(), Longitude = longitude.GetValueOrDefault(), DepthInKm = depthKm.GetValueOrDefault(), DepthDesc = depthDesc, UtcTime = utcTime, LocalTime = localTime }; } return quake; } private T GetElementValue<T>(SyndicationItem entry, String name) { var el = entry.ElementExtensions.Where(e => e.OuterName == name).FirstOrDefault(); T value = default(T); if ( el != null ) { value = el.GetObject<T>(); } return value; } private double? TryParse(String value) { double d; if ( Double.TryParse(value, out d) ) { return d; } return null; } /// <summary> /// Gets the feed at the specified URL. /// </summary> /// <param name="url">The URL.</param> /// <returns>A <see cref="SyndicationFeed"/> object.</returns> public static SyndicationFeed GetFeed(String url) { SyndicationFeed feed = null; try { log.Debug("Loading RSS feed: " + url); using ( var reader = XmlReader.Create(url) ) { feed = SyndicationFeed.Load(reader); } } catch ( Exception ex ) { log.Error("Error occurred while loading RSS feed: " + url, ex); } return feed; } } } The only method that will be generated in the client side proxy class, EarthquakeContext, will be the GetEarthquakes() method. The reason being that it is the only public instance method and it returns an IQueryable<Earthquake> collection that can be consumed by the client application. GetEarthquakes() calls the static GetFeed(String) method, which utilizes the built in SyndicationFeed API to load the external data feed. You will need to add a reference to the System.ServiceModel.Web library in order to take advantage of the RSS/Atom reader. The API will also allow you to create your own feeds to serve up in your applications. Model I have also created a Model folder and added a new class, Earthquake.cs. The Earthquake object will hold the various properties returned from the Atom feed. Here is a sample of the code for that class. Notice the [Key] attribute on the Id property, which is required by RIA Services to uniquely identify the entity. using System; using System.Collections.Generic; using System.Linq; using System.Runtime.Serialization; using System.ComponentModel.DataAnnotations; namespace EarthquakeLocator.Web.Model { /// <summary> /// Represents an earthquake occurrence and related information. /// </summary> [DataContract] public class Earthquake { /// <summary> /// Gets or sets the id. /// </summary> /// <value>The id.</value> [Key] [DataMember] public string Id { get; set; } /// <summary> /// Gets or sets the title. /// </summary> /// <value>The title.</value> [DataMember] public string Title { get; set; } /// <summary> /// Gets or sets the summary. /// </summary> /// <value>The summary.</value> [DataMember] public string Summary { get; set; } // additional properties omitted } } View Model The recent trend to use the MVVM pattern for WPF and Silverlight provides a great way to separate the data and behavior logic out of the user interface layer of your client applications. I have chosen to use the MVVM Light Toolkit for the Earthquake Locator, but there are other options out there if you prefer another library. That said, I went ahead and created a ViewModel folder in the Silverlight project and added a EarthquakeViewModel class that derives from ViewModelBase. Here is the code: using System; using System.Collections.ObjectModel; using System.ComponentModel.Composition; using System.ComponentModel.Composition.Hosting; using Microsoft.Maps.MapControl; using GalaSoft.MvvmLight; using EarthquakeLocator.Web.Model; using EarthquakeLocator.Web.Services; namespace EarthquakeLocator.ViewModel { /// <summary> /// Provides data for views displaying earthquake information. /// </summary> public class EarthquakeViewModel : ViewModelBase { [Import] public EarthquakeContext Context; /// <summary> /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class. /// </summary> public EarthquakeViewModel() { var catalog = new AssemblyCatalog(GetType().Assembly); var container = new CompositionContainer(catalog); container.ComposeParts(this); Initialize(); } /// <summary> /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class. /// </summary> /// <param name="context">The context.</param> public EarthquakeViewModel(EarthquakeContext context) { Context = context; Initialize(); } private void Initialize() { MapCenter = new Location(20, -170); ZoomLevel = 2; } #region Private Methods private void OnAutoLoadDataChanged() { LoadEarthquakes(); } private void LoadEarthquakes() { var query = Context.GetEarthquakesQuery(); Context.Earthquakes.Clear(); Context.Load(query, (op) => { if ( !op.HasError ) { foreach ( var item in op.Entities ) { Earthquakes.Add(item); } } }, null); } #endregion Private Methods #region Properties private bool autoLoadData; /// <summary> /// Gets or sets a value indicating whether to auto load data. /// </summary> /// <value><c>true</c> if auto loading data; otherwise, <c>false</c>.</value> public bool AutoLoadData { get { return autoLoadData; } set { if ( autoLoadData != value ) { autoLoadData = value; RaisePropertyChanged("AutoLoadData"); OnAutoLoadDataChanged(); } } } private ObservableCollection<Earthquake> earthquakes; /// <summary> /// Gets the collection of earthquakes to display. /// </summary> /// <value>The collection of earthquakes.</value> public ObservableCollection<Earthquake> Earthquakes { get { if ( earthquakes == null ) { earthquakes = new ObservableCollection<Earthquake>(); } return earthquakes; } } private Location mapCenter; /// <summary> /// Gets or sets the map center. /// </summary> /// <value>The map center.</value> public Location MapCenter { get { return mapCenter; } set { if ( mapCenter != value ) { mapCenter = value; RaisePropertyChanged("MapCenter"); } } } private double zoomLevel; /// <summary> /// Gets or sets the zoom level. /// </summary> /// <value>The zoom level.</value> public double ZoomLevel { get { return zoomLevel; } set { if ( zoomLevel != value ) { zoomLevel = value; RaisePropertyChanged("ZoomLevel"); } } } #endregion Properties } } The EarthquakeViewModel class contains all of the properties that will be bound to by the various controls in our views. Be sure to read through the LoadEarthquakes() method, which handles calling the GetEarthquakes() method in our EarthquakeService via the EarthquakeContext proxy, and also transfers the loaded entities into the view model’s Earthquakes collection. Another thing to notice is what’s going on in the default constructor. I chose to use the Managed Extensibility Framework (MEF) for my composition needs, but you can use any dependency injection library or none at all. To allow the EarthquakeContext class to be discoverable by MEF, I added the following partial class so that I could supply the appropriate [Export] attribute: using System; using System.ComponentModel.Composition; namespace EarthquakeLocator.Web.Services { /// <summary> /// The client side proxy for the EarthquakeService class. /// </summary> [Export] public partial class EarthquakeContext { } } One last piece I wanted to point out before moving on to the user interface, I added a client side partial class for the Earthquake entity that contains helper properties that we will bind to later: using System; namespace EarthquakeLocator.Web.Model { /// <summary> /// Represents an earthquake occurrence and related information. /// </summary> public partial class Earthquake { /// <summary> /// Gets the location based on the current Latitude/Longitude. /// </summary> /// <value>The location.</value> public string Location { get { return String.Format("{0},{1}", Latitude, Longitude); } } /// <summary> /// Gets the size based on the Magnitude. /// </summary> /// <value>The size.</value> public double Size { get { return (Magnitude * 3); } } } } View Now the fun part! Usually, I would create a Views folder to place all of my View controls in, but I took the easy way out and added the following XAML code to the default MainPage.xaml file. Be sure to add the bing prefix associating the Microsoft.Maps.MapControl namespace after adding the assembly reference to your project. The MVVM Light Toolkit project templates come with a ViewModelLocator class that you can use via a static resource, but I am instantiating the EarthquakeViewModel directly in my user control. I am setting the AutoLoadData property to true as a way to trigger the LoadEarthquakes() method call. The MapItemsControl found within the <bing:Map> control binds its ItemsSource property to the Earthquakes collection of the view model, and since it is an ObservableCollection<T>, we get the automatic two way data binding via the INotifyCollectionChanged interface. <UserControl x:Class="EarthquakeLocator.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl" xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel" mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" > <UserControl.Resources> <DataTemplate x:Key="EarthquakeTemplate"> <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1" Width="{Binding Size}" Height="{Binding Size}" bing:MapLayer.Position="{Binding Location}" bing:MapLayer.PositionOrigin="Center"> <ToolTipService.ToolTip> <StackPanel> <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" /> <TextBlock Text="{Binding UtcTime}" /> <TextBlock Text="{Binding LocalTime}" /> <TextBlock Text="{Binding DepthDesc}" /> </StackPanel> </ToolTipService.ToolTip> </Ellipse> </DataTemplate> </UserControl.Resources> <UserControl.DataContext> <vm:EarthquakeViewModel AutoLoadData="True" /> </UserControl.DataContext> <Grid x:Name="LayoutRoot"> <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--" Center="{Binding MapCenter, Mode=TwoWay}" ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}"> <bing:MapItemsControl ItemsSource="{Binding Earthquakes}" ItemTemplate="{StaticResource EarthquakeTemplate}" /> </bing:Map> </Grid> </UserControl> The EarthquakeTemplate defines the Ellipse that will represent each earthquake, the Width and Height that are determined by the Magnitude, the Position on the map, and also the tooltip that will appear when we mouse over each data point. Running the application will give us the following result (shown with a tooltip example): That concludes this portion of our show but I plan on implementing additional functionality in later blog posts. Be sure to come back soon to see the next installments in this series. Enjoy! Additional Resources USGS Earthquake Data Feeds Brad Abrams shows how RIA Services and MVVM can work together

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Installing UCMA 3.0 and Creating a Communications Server "14"Trusted Application Pool

A lot of setup and administration tasks have gotten a lot easier in Communications Server 14; one of them is building an application server to develop and run your UCMA 3.0 applications on. In this post, Ill walk you through installing the UCMA 3.0 Core SDK and creating a Trusted Application Pool on the server, thus adding it to the Communications Server 14 topology and allowing you to host and run UCMA 3.0 applications on it. Note: These instructions will change slightly as the bits get updated for the eventual Beta release I will update this post as soon as I get a chance to run this setup on a more recent build. Im doing the install on a simple Communications Server 14 topology consisting of the following Windows Server 2008 R2 Hyper-V images: DC Domain Controller ExchangeUM Exchange Server 2010 CS-SE Microsoft Communications Server 2010 Standard Edition TS Development machine Ill walk through setting up UCMA 3.0 on the TS VM, which is a fully patched Windows Server 2008 R2 machine that is joined to the Fabrikam domain. Im also running Visual Studio 2010 on this VM because I intend to use it as a development machine. In a future post, Ill walk through installing just the UCMA 3.0 run time to build a true production UCMA application server. Im making a couple of assumptions here: You have an existing CS 2010 site and cluster configured(well look at this in a future post) Youre starting with a fully patched Windows Server 2008 R2 machine The machine is joined to your domain This walkthrough was done in my Fabrikam VM environment but can easily be modified for your own environment. Installing the UCMA 3.0 SDK Lets start by installing the UCMA 3.0 SDK. Run UcmaSdkWebDownload.msi to kick off the SDK installer package extract process. The installed package is extracted to C: >> Program Files >> Microsoft UCMA 3.0 >> SDK Installer Package. Browse there and run setup.exe. Click Install to install the UCMA 3.0 Core SDK and Workflow SDK. Install Communications Server Core Components UCMA 3.0 introduces a new concept called Auto-provisioning, which is most easily explained from the developer point of view. Remember what your app.config looked it in UCMA 2.0? You had to store the application GRUU, the trusted contact SIP Uri, the port for your application, and the name of the certificate authority. Thats all gone with auto-provisioning all you need in your app.config is your ApplicationId, e.g.: urn:application:MyApplication. How does CS 2010 do this? All of the applications configuration data is associated with the applications id. UCMA also queries a replicated copy of the Central Management Database to retrieve the applications configuration data and also the configuration data for any endpoints. In this step, well run Bootstrapper.exe to install the CS Core components, this checked for the following components and installs them if they are not already present: VcRedist Sqlexpress Sqlnativeclient Sqlbackcompat Ucmaredist OcsCore.msi Open a command window at C: >> Program Files >> Microsoft Communications Server 2010 >> Deployment and run the following command: Bootstrapper.exe /BootstrapReplica /MinCache /SourceDirectory:"%ProgramFiles%\Microsoft UCMA 3.0\SDK Installer Package\Prereq\BootstrapperCache" Create a New Trusted Application Pool The next step is to create a new trusted application pool for the new server. Fire up the Communications Server Management Shell from Start >> Microsoft Communications Server 2010 >> Communications Server Management Shell and enter the following PowerShell command: New-CsTrustedApplicationPool -Identity <FQDN of Server> -Registrar <FQDN of CS Server> -Site <CS Site Name> Verify that the new server was added to the CS topology by running the following PowerShell command: (Get-CsTopology -AsXml).ToString() > Topology.xml This created a file called Topology.xml in the directory that you ran the command from. Open the file and find the Clusters section and look for a node for the new server. The Cluster Fqdn is the name of your server, and note the name of the Site that this Cluster is a part of. <Cluster Fqdn="appsrv.fabrikam.com" RequiresReplication="true" RequiresSetup="true"> <ClusterId SiteId="UcMarketing2" Number="5" /> <Machine OrdinalInCluster="1" Fqdn="appsrv.fabrikam.com"> <NetInterface InterfaceSide="Primary" InterfaceNumber="1" IPAddress="0.0.0.0" /> </Machine> </Cluster> Configure CS Management Store Replication At this point, we have the CS Core components installed and the server configured as a trusted application pool. We now need to set up replication so that the Central Management Store replicates down to the new server. From the Communications Server Management Shell, run the following PowerShell command to enable the Replica service on the new server: Enable-CSReplica The Replica service is enabled, but hasn't done anything yet. This can be verified by running the following PowerShell command to check the replication status for the various servers in the topology: Get-CSManagementStoreReplicationStatus You can see in the screenshot below that the UpToDate property of the new server is still False Run the following PowerShell command to force the replication to run: Invoke-CSManagementStoreReplicationStatus Run Get-CSManagementStoreReplicationStatus again to verify that the new service is now up to date Request and Set a New Certificate The last step in the process is to request a new certificate from the certificate authority on the domain and assign it to the new server. From the Communications Server Management Shell, run the following PowerShell command to request a new certificate: Request-CSCertificate -Action new -Type default -CA <Domain Controller FQDN>\<Certificate Authority> Setting the -Verbose switch on the cmdlet creates an Xml file with its output. Open the Xml file and copy the thumbprint of the generated certificate. <?xml version="1.0" encoding="utf-8"?> <Action Name="Request-CsCertificate" Time="20100512T212258"> <Action Name="Request-CsCertificate" Time="20100512T212258"> <Info Title="Connection" Time="20100512T212258">Data Source=(local)\rtclocal;Initial Catalog=xds;Integrated Security=True</Info> <Action Time="20100512T212258"> <Info Title="Certificate use" Time="20100512T212258">urn:certref:default</Info> <Info Title="Subject distinguished name" Time="20100512T212258">CN="appsrv2.fabrikam.com"</Info> <Info Time="20100512T212259">The certificate request is submitted to the Certification Authority dc.fabrikam.com\FabrikamCA.</Info> <Info Time="20100512T212259">The certificate was issued.</Info> <Info Time="20100512T212259">The certificate was imported with thumbprint AFC3C46E459C1A39AD06247676F3555826DBF705.</Info> <Complete Time="20100512T212259" /> </Action> <Info Title="command status" Time="20100512T212259">Command execution processing completed</Info> <Action Name="DeploymentXdsCmdlet.SaveCachedItems" Time="20100512T212259"> <Info Time="20100512T212259">0 updates</Info> <Complete Time="20100512T212259" /> </Action> <Info Title="command status" Time="20100512T212259">Command has completed</Info> </Action> </Action> Run the following PowerShell command to set the certificate: Set-CsCertificate -Type Default -Thumbprint <Thumbprint> Wrapping Up You now have a new UCMA 3.0 application server in your Communications Server 2010 server topology. You can provision trusted applications and trusted application endpoints on the new server using the Communications Server 2010 Management Shell. Well take a look at how to do that in another post. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

- by Joe Mayo

One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow. In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <fieldset> <legend>Twitter Friends</legend> <div> <%= Html.DropDownListFor( twendVM => twendVM.FriendNames, Model.FriendNames, "<All Friends>") %> </div> <div> <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets) .Name("TwitterFriendsGrid") .Columns(cols => { cols.Template(col => { %> <img src="<%= col.ImageUrl %>" alt="<%= col.ScreenName %>" /> <% }); cols.Bound(col => col.ScreenName); cols.Bound(col => col.Tweet); }) .Render(); %> </div> </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View. Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below, so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList. This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates. This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>. In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects. You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library. Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal. Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

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Azure - Part 4 - Table Storage Service in Windows Azure

- by Shaun

In Windows Azure platform there are 3 storage we can use to save our data on the cloud. They are the Table, Blob and Queue. Before the Chinese New Year Microsoft announced that Azure SDK 1.1 had been released and it supports a new type of storage – Drive, which allows us to operate NTFS files on the cloud. I will cover it in the coming few posts but now I would like to talk a bit about the Table Storage. Concept of Table Storage Service The most common development scenario is to retrieve, create, update and remove data from the data storage. In the normal way we communicate with database. When we attempt to move our application over to the cloud the most common requirement should be have a storage service. Windows Azure provides a in-build service that allow us to storage the structured data, which is called Windows Azure Table Storage Service. The data stored in the table service are like the collection of entities. And the entities are similar to rows or records in the tradtional database. An entity should had a partition key, a row key, a timestamp and set of properties. You can treat the partition key as a group name, the row key as a primary key and the timestamp as the identifer for solving the concurrency problem. Different with a table in a database, the table service does not enforce the schema for tables, which means you can have 2 entities in the same table with different property sets. The partition key is being used for the load balance of the Azure OS and the group entity transaction. As you know in the cloud you will never know which machine is hosting your application and your data. It could be moving based on the transaction weight and the number of the requests. If the Azure OS found that there are many requests connect to your Book entities with the partition key equals “Novel” it will move them to another idle machine to increase the performance. So when choosing the partition key for your entities you need to make sure they indecate the category or gourp information so that the Azure OS can perform the load balance as you wish. Consuming the Table Although the table service looks like a database, you cannot access it through the way you are using now, neither ADO.NET nor ODBC. The table service exposed itself by ADO.NET Data Service protocol, which allows you can consume it through the RESTful style by Http requests. The Azure SDK provides a sets of classes for us to connect it. There are 2 classes we might need: TableServiceContext and TableServiceEntity. The TableServiceContext inherited from the DataServiceContext, which represents the runtime context of the ADO.NET data service. It provides 4 methods mainly used by us: CreateQuery: It will create a IQueryable instance from a given type of entity. AddObject: Add the specified entity into Table Service. UpdateObject: Update an existing entity in the Table Service. DeleteObject: Delete an entity from the Table Service. Beofre you operate the table service you need to provide the valid account information. It’s something like the connect string of the database but with your account name and the account key when you created the storage service on the Windows Azure Development Portal. After getting the CloudStorageAccount you can create the CloudTableClient instance which provides a set of methods for using the table service. A very useful method would be CreateTableIfNotExist. It will create the table container for you if it’s not exsited. And then you can operate the eneities to that table through the methods I mentioned above. Let me explain a bit more through an exmaple. We always like code rather than sentence. Straightforward Accessing to the Table Here I would like to build a WCF service on the Windows Azure platform, and for now just one requirement: it would allow the client to create an account entity on the table service. The WCF service would have a method named Register and accept an instance of the account which the client wants to create. After perform some validation it will add the entity into the table service. So the first thing I should do is to create a Cloud Application on my VIstial Studio 2010 RC. (The Azure SDK 1.1 only supports VS2008 and VS2010 RC.) The solution should be like this below. Then I added a configuration items for the storage account through the Settings section under the cloud project. (Double click the Services file under Roles folder and navigate to the Setting section.) This setting will be used when to retrieve my storage account information. Since for now I just in the development phase I will select “UseDevelopmentStorage=true”. And then I navigated to the WebRole.cs file under my WCF project. If you have read my previous posts you would know that this file defines the process when the application start, and terminate on the cloud. What I need to do is to when the application start, set the configuration publisher to load my config file with the config name I specified. So the code would be like below. I removed the original service and contract created by the VS template and add my IAccountService contract and its implementation class - AccountService. And I add the service method Register with the parameters: email, password and it will return a boolean value to indicates the result which is very simple. At this moment if I press F5 the application will be established on my local development fabric and I can see my service runs well through the browser. Let’s implement the service method Rigister, add a new entity to the table service. As I said before the entities you want to store in the table service must have 3 properties: partition key, row key and timespan. You can create a class with these 3 properties. The Azure SDK provides us a base class for that named TableServiceEntity in Microsoft.WindowsAzure.StorageClient namespace. So what we need to do is more simply, create a class named Account and let it derived from the TableServiceEntity. And I need to add my own properties: Email, Password, DateCreated and DateDeleted. The DateDeleted is a nullable date time value to indecate whether this entity had been deleted and when. Do you notice that I missed something here? Yes it’s the partition key and row key I didn’t assigned. The TableServiceEntity base class defined 2 constructors one was a parameter-less constructor which will be used to fill values into the properties from the table service when retrieving data. The other was one with 2 parameters: partition key and row key. As I said below the partition key may affect the load balance and the row key must be unique so here I would like to use the email as the parition key and the email plus a Guid as the row key. OK now we finished the entity class we need to store onto the table service. The next step is to create a data access class for us to add it. Azure SDK gives us a base class for it named TableServiceContext as I mentioned below. So let’s create a class for operate the Account entities. The TableServiceContext need the storage account information for its constructor. It’s the combination of the storage service URI that we will create on Windows Azure platform, and the relevant account name and key. The TableServiceContext will use this information to find the related address and verify the account to operate the storage entities. Hence in my AccountDataContext class I need to override this constructor and pass the storage account into it. All entities will be saved in the table storage with one or many tables which we call them “table containers”. Before we operate an entity we need to make sure that the table container had been created on the storage. There’s a method we can use for that: CloudTableClient.CreateTableIfNotExist. So in the constructor I will perform it firstly to make sure all method will be invoked after the table had been created. Notice that I passed the storage account enpoint URI and the credentials to specify where my storage is located and who am I. Another advise is that, make your entity class name as the same as the table name when create the table. It will increase the performance when you operate it over the cloud especially querying. Since the Register WCF method will add a new account into the table service, here I will create a relevant method to add the account entity. Before implement, I should add a reference - System.Data.Services.Client to the project. This reference provides some common method within the ADO.NET Data Service which can be used in the Windows Azure Table Service. I will use its AddObject method to create my account entity. Since the table service are not fully implemented the ADO.NET Data Service, there are some methods in the System.Data.Services.Client that TableServiceContext doesn’t support, such as AddLinks, etc. Then I implemented the serivce method to add the account entity through the AccountDataContext. You can see in the service implmentation I load the storage account information through my configuration file and created the account table entity from the parameters. Then I created the AccountDataContext. If it’s my first time to invoke this method the constructor of the AccountDataContext will create a table container for me. Then I use Add method to add the account entity into the table. Next, let’s create a farely simple client application to test this service. I created a windows console application and added a service reference to my WCF service. The metadata information of the WCF service cannot be retrieved if it’s deployed on the Windows Azure even though the <serviceMetadata httpGetEnabled="true"/> had been set. If we need to get its metadata we can deploy it on the local development service and then changed the endpoint to the address which is on the cloud. In the client side app.config file I specified the endpoint to the local development fabric address. And the just implement the client to let me input an email and a password then invoke the WCF service to add my acocunt. Let’s run my application and see the result. Of course it should return TRUE to me. And in the local SQL Express I can see the data had been saved in the table. Summary In this post I explained more about the Windows Azure Table Storage Service. I also created a small application for demostration of how to connect and consume it through the ADO.NET Data Service Managed Library provided within the Azure SDK. I only show how to create an eneity in the storage service. In the next post I would like to explain about how to query the entities with conditions thruogh LINQ. I also would like to refactor my AccountDataContext class to make it dyamic for any kinds of entities. Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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Rendering ASP.NET MVC Views to String

- by Rick Strahl

It's not uncommon in my applications that I require longish text output that does not have to be rendered into the HTTP output stream. The most common scenario I have for 'template driven' non-Web text is for emails of all sorts. Logon confirmations and verifications, email confirmations for things like orders, status updates or scheduler notifications - all of which require merged text output both within and sometimes outside of Web applications. On other occasions I also need to capture the output from certain views for logging purposes. Rather than creating text output in code, it's much nicer to use the rendering mechanism that ASP.NET MVC already provides by way of it's ViewEngines - using Razor or WebForms views - to render output to a string. This is nice because it uses the same familiar rendering mechanism that I already use for my HTTP output and it also solves the problem of where to store the templates for rendering this content in nothing more than perhaps a separate view folder. The good news is that ASP.NET MVC's rendering engine is much more modular than the full ASP.NET runtime engine which was a real pain in the butt to coerce into rendering output to string. With MVC the rendering engine has been separated out from core ASP.NET runtime, so it's actually a lot easier to get View output into a string. Getting View Output from within an MVC Application If you need to generate string output from an MVC and pass some model data to it, the process to capture this output is fairly straight forward and involves only a handful of lines of code. The catch is that this particular approach requires that you have an active ControllerContext that can be passed to the view. This means that the following approach is limited to access from within Controller methods. Here's a class that wraps the process and provides both instance and static methods to handle the rendering:/// <summary> /// Class that renders MVC views to a string using the /// standard MVC View Engine to render the view. /// /// Note: This class can only be used within MVC /// applications that have an active ControllerContext. /// </summary> public class ViewRenderer { /// <summary> /// Required Controller Context /// </summary> protected ControllerContext Context { get; set; } public ViewRenderer(ControllerContext controllerContext) { Context = controllerContext; } /// <summary> /// Renders a full MVC view to a string. Will render with the full MVC /// View engine including running _ViewStart and merging into _Layout /// </summary> /// <param name="viewPath"> /// The path to the view to render. Either in same controller, shared by /// name or as fully qualified ~/ path including extension /// </param> /// <param name="model">The model to render the view with</param> /// <returns>String of the rendered view or null on error</returns> public string RenderView(string viewPath, object model) { return RenderViewToStringInternal(viewPath, model, false); } /// <summary> /// Renders a partial MVC view to string. Use this method to render /// a partial view that doesn't merge with _Layout and doesn't fire /// _ViewStart. /// </summary> /// <param name="viewPath"> /// The path to the view to render. Either in same controller, shared by /// name or as fully qualified ~/ path including extension /// </param> /// <param name="model">The model to pass to the viewRenderer</param> /// <returns>String of the rendered view or null on error</returns> public string RenderPartialView(string viewPath, object model) { return RenderViewToStringInternal(viewPath, model, true); } public static string RenderView(string viewPath, object model, ControllerContext controllerContext) { ViewRenderer renderer = new ViewRenderer(controllerContext); return renderer.RenderView(viewPath, model); } public static string RenderPartialView(string viewPath, object model, ControllerContext controllerContext) { ViewRenderer renderer = new ViewRenderer(controllerContext); return renderer.RenderPartialView(viewPath, model); } protected string RenderViewToStringInternal(string viewPath, object model, bool partial = false) { // first find the ViewEngine for this view ViewEngineResult viewEngineResult = null; if (partial) viewEngineResult = ViewEngines.Engines.FindPartialView(Context, viewPath); else viewEngineResult = ViewEngines.Engines.FindView(Context, viewPath, null); if (viewEngineResult == null) throw new FileNotFoundException(Properties.Resources.ViewCouldNotBeFound); // get the view and attach the model to view data var view = viewEngineResult.View; Context.Controller.ViewData.Model = model; string result = null; using (var sw = new StringWriter()) { var ctx = new ViewContext(Context, view, Context.Controller.ViewData, Context.Controller.TempData, sw); view.Render(ctx, sw); result = sw.ToString(); } return result; } } The key is the RenderViewToStringInternal method. The method first tries to find the view to render based on its path which can either be in the current controller's view path or the shared view path using its simple name (PasswordRecovery) or alternately by its full virtual path (~/Views/Templates/PasswordRecovery.cshtml). This code should work both for Razor and WebForms views although I've only tried it with Razor Views. Note that WebForms Views might actually be better for plain text as Razor adds all sorts of white space into its output when there are code blocks in the template. The Web Forms engine provides more accurate rendering for raw text scenarios. Once a view engine is found the view to render can be retrieved. Views in MVC render based on data that comes off the controller like the ViewData which contains the model along with the actual ViewData and ViewBag. From the View and some of the Context data a ViewContext is created which is then used to render the view with. The View picks up the Model and other data from the ViewContext internally and processes the View the same it would be processed if it were to send its output into the HTTP output stream. The difference is that we can override the ViewContext's output stream which we provide and capture into a StringWriter(). After rendering completes the result holds the output string. If an error occurs the error behavior is similar what you see with regular MVC errors - you get a full yellow screen of death including the view error information with the line of error highlighted. It's your responsibility to handle the error - or let it bubble up to your regular Controller Error filter if you have one. To use the simple class you only need a single line of code if you call the static methods. Here's an example of some Controller code that is used to send a user notification to a customer via email in one of my applications:[HttpPost] public ActionResult ContactSeller(ContactSellerViewModel model) { InitializeViewModel(model); var entryBus = new busEntry(); var entry = entryBus.LoadByDisplayId(model.EntryId); if ( string.IsNullOrEmpty(model.Email) ) entryBus.ValidationErrors.Add("Email address can't be empty.","Email"); if ( string.IsNullOrEmpty(model.Message)) entryBus.ValidationErrors.Add("Message can't be empty.","Message"); model.EntryId = entry.DisplayId; model.EntryTitle = entry.Title; if (entryBus.ValidationErrors.Count > 0) { ErrorDisplay.AddMessages(entryBus.ValidationErrors); ErrorDisplay.ShowError("Please correct the following:"); } else { string message = ViewRenderer.RenderView("~/views/template/ContactSellerEmail.cshtml",model, ControllerContext); string title = entry.Title + " (" + entry.DisplayId + ") - " + App.Configuration.ApplicationName; AppUtils.SendEmail(title, message, model.Email, entry.User.Email, false, false)) } return View(model); } Simple! The view in this case is just a plain MVC view and in this case it's a very simple plain text email message (edited for brevity here) that is created and sent off:@model ContactSellerViewModel @{ Layout = null; }re: @Model.EntryTitle @Model.ListingUrl @Model.Message ** SECURITY ADVISORY - AVOID SCAMS ** Avoid: wiring money, cross-border deals, work-at-home ** Beware: cashier checks, money orders, escrow, shipping ** More Info: @(App.Configuration.ApplicationBaseUrl)scams.html Obviously this is a very simple view (I edited out more from this page to keep it brief) - but other template views are much more complex HTML documents or long messages that are occasionally updated and they are a perfect fit for Razor rendering. It even works with nested partial views and _layout pages. Partial Rendering Notice that I'm rendering a full View here. In the view I explicitly set the Layout=null to avoid pulling in _layout.cshtml for this view. This can also be controlled externally by calling the RenderPartial method instead: string message = ViewRenderer.RenderPartialView("~/views/template/ContactSellerEmail.cshtml",model, ControllerContext); with this line of code no layout page (or _viewstart) will be loaded, so the output generated is just what's in the view. I find myself using Partials most of the time when rendering templates, since the target of templates usually tend to be emails or other HTML fragment like output, so the RenderPartialView() method is definitely useful to me. Rendering without a ControllerContext The preceding class is great when you're need template rendering from within MVC controller actions or anywhere where you have access to the request Controller. But if you don't have a controller context handy - maybe inside a utility function that is static, a non-Web application, or an operation that runs asynchronously in ASP.NET - which makes using the above code impossible. I haven't found a way to manually create a Controller context to provide the ViewContext() what it needs from outside of the MVC infrastructure. However, there are ways to accomplish this, but they are a bit more complex. It's possible to host the RazorEngine on your own, which side steps all of the MVC framework and HTTP and just deals with the raw rendering engine. I wrote about this process in Hosting the Razor Engine in Non-Web Applications a long while back. It's quite a process to create a custom Razor engine and runtime, but it allows for all sorts of flexibility. There's also a RazorEngine CodePlex project that does something similar. I've been meaning to check out the latter but haven't gotten around to it since I have my own code to do this. The trick to hosting the RazorEngine to have it behave properly inside of an ASP.NET application and properly cache content so templates aren't constantly rebuild and reparsed. Anyway, in the same app as above I have one scenario where no ControllerContext is available: I have a background scheduler running inside of the app that fires on timed intervals. This process could be external but because it's lightweight we decided to fire it right inside of the ASP.NET app on a separate thread. In my app the code that renders these templates does something like this:var model = new SearchNotificationViewModel() { Entries = entries, Notification = notification, User = user }; // TODO: Need logging for errors sending string razorError = null; var result = AppUtils.RenderRazorTemplate("~/views/template/SearchNotificationTemplate.cshtml", model, razorError); which references a couple of helper functions that set up my RazorFolderHostContainer class:public static string RenderRazorTemplate(string virtualPath, object model,string errorMessage = null) { var razor = AppUtils.CreateRazorHost(); var path = virtualPath.Replace("~/", "").Replace("~", "").Replace("/", "\\"); var merged = razor.RenderTemplateToString(path, model); if (merged == null) errorMessage = razor.ErrorMessage; return merged; } /// <summary> /// Creates a RazorStringHostContainer and starts it /// Call .Stop() when you're done with it. /// /// This is a static instance /// </summary> /// <param name="virtualPath"></param> /// <param name="binBasePath"></param> /// <param name="forceLoad"></param> /// <returns></returns> public static RazorFolderHostContainer CreateRazorHost(string binBasePath = null, bool forceLoad = false) { if (binBasePath == null) { if (HttpContext.Current != null) binBasePath = HttpContext.Current.Server.MapPath("~/"); else binBasePath = AppDomain.CurrentDomain.BaseDirectory; } if (_RazorHost == null || forceLoad) { if (!binBasePath.EndsWith("\\")) binBasePath += "\\"; //var razor = new RazorStringHostContainer(); var razor = new RazorFolderHostContainer(); razor.TemplatePath = binBasePath; binBasePath += "bin\\"; razor.BaseBinaryFolder = binBasePath; razor.UseAppDomain = false; razor.ReferencedAssemblies.Add(binBasePath + "ClassifiedsBusiness.dll"); razor.ReferencedAssemblies.Add(binBasePath + "ClassifiedsWeb.dll"); razor.ReferencedAssemblies.Add(binBasePath + "Westwind.Utilities.dll"); razor.ReferencedAssemblies.Add(binBasePath + "Westwind.Web.dll"); razor.ReferencedAssemblies.Add(binBasePath + "Westwind.Web.Mvc.dll"); razor.ReferencedAssemblies.Add("System.Web.dll"); razor.ReferencedNamespaces.Add("System.Web"); razor.ReferencedNamespaces.Add("ClassifiedsBusiness"); razor.ReferencedNamespaces.Add("ClassifiedsWeb"); razor.ReferencedNamespaces.Add("Westwind.Web"); razor.ReferencedNamespaces.Add("Westwind.Utilities"); _RazorHost = razor; _RazorHost.Start(); //_RazorHost.Engine.Configuration.CompileToMemory = false; } return _RazorHost; } The RazorFolderHostContainer essentially is a full runtime that mimics a folder structure like a typical Web app does including caching semantics and compiling code only if code changes on disk. It maps a folder hierarchy to views using the ~/ path syntax. The host is then configured to add assemblies and namespaces. Unfortunately the engine is not exactly like MVC's Razor - the expression expansion and code execution are the same, but some of the support methods like sections, helpers etc. are not all there so templates have to be a bit simpler. There are other folder hosts provided as well to directly execute templates from strings (using RazorStringHostContainer). The following is an example of an HTML email template @inherits RazorHosting.RazorTemplateFolderHost <ClassifiedsWeb.SearchNotificationViewModel> <html> <head> <title>Search Notifications</title> <style> body { margin: 5px;font-family: Verdana, Arial; font-size: 10pt;} h3 { color: SteelBlue; } .entry-item { border-bottom: 1px solid grey; padding: 8px; margin-bottom: 5px; } </style> </head> <body> Hello @Model.User.Name,<br /> <p>Below are your Search Results for the search phrase:</p> <h3>@Model.Notification.SearchPhrase</h3> <small>since @TimeUtils.ShortDateString(Model.Notification.LastSearch)</small> <hr /> You can see that the syntax is a little different. Instead of the familiar @model header the raw Razor @inherits tag is used to specify the template base class (which you can extend). I took a quick look through the feature set of RazorEngine on CodePlex (now Github I guess) and the template implementation they use is closer to MVC's razor but there are other differences. In the end don't expect exact behavior like MVC templates if you use an external Razor rendering engine. This is not what I would consider an ideal solution, but it works well enough for this project. My biggest concern is the overhead of hosting a second razor engine in a Web app and the fact that here the differences in template rendering between 'real' MVC Razor views and another RazorEngine really are noticeable. You win some, you lose some It's extremely nice to see that if you have a ControllerContext handy (which probably addresses 99% of Web app scenarios) rendering a view to string using the native MVC Razor engine is pretty simple. Kudos on making that happen - as it solves a problem I see in just about every Web application I work on. But it is a bummer that a ControllerContext is required to make this simple code work. It'd be really sweet if there was a way to render views without being so closely coupled to the ASP.NET or MVC infrastructure that requires a ControllerContext. Alternately it'd be nice to have a way for an MVC based application to create a minimal ControllerContext from scratch - maybe somebody's been down that path. I tried for a few hours to come up with a way to make that work but gave up in the soup of nested contexts (MVC/Controller/View/Http). I suspect going down this path would be similar to hosting the ASP.NET runtime requiring a WorkerRequest. Brrr…. The sad part is that it seems to me that a View should really not require much 'context' of any kind to render output to string. Yes there are a few things that clearly are required like paths to the virtual and possibly the disk paths to the root of the app, but beyond that view rendering should not require much. But, no such luck. For now custom RazorHosting seems to be the only way to make Razor rendering go outside of the MVC context… Resources Full ViewRenderer.cs source code from Westwind.Web.Mvc library Hosting the Razor Engine for Non-Web Applications RazorEngine on GitHub© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET ASP.NET MVC Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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jQuery Templates and Data Linking (and Microsoft contributing to jQuery)

- by ScottGu

The jQuery library has a passionate community of developers, and it is now the most widely used JavaScript library on the web today. Two years ago I announced that Microsoft would begin offering product support for jQuery, and that we’d be including it in new versions of Visual Studio going forward. By default, when you create new ASP.NET Web Forms and ASP.NET MVC projects with VS 2010 you’ll find jQuery automatically added to your project. A few weeks ago during my second keynote at the MIX 2010 conference I announced that Microsoft would also begin contributing to the jQuery project. During the talk, John Resig -- the creator of the jQuery library and leader of the jQuery developer team – talked a little about our participation and discussed an early prototype of a new client templating API for jQuery. In this blog post, I’m going to talk a little about how my team is starting to contribute to the jQuery project, and discuss some of the specific features that we are working on such as client-side templating and data linking (data-binding). Contributing to jQuery jQuery has a fantastic developer community, and a very open way to propose suggestions and make contributions. Microsoft is following the same process to contribute to jQuery as any other member of the community. As an example, when working with the jQuery community to improve support for templating to jQuery my team followed the following steps: We created a proposal for templating and posted the proposal to the jQuery developer forum (http://forum.jquery.com/topic/jquery-templates-proposal and http://forum.jquery.com/topic/templating-syntax ). After receiving feedback on the forums, the jQuery team created a prototype for templating and posted the prototype at the Github code repository (http://github.com/jquery/jquery-tmpl ). We iterated on the prototype, creating a new fork on Github of the templating prototype, to suggest design improvements. Several other members of the community also provided design feedback by forking the templating code. There has been an amazing amount of participation by the jQuery community in response to the original templating proposal (over 100 posts in the jQuery forum), and the design of the templating proposal has evolved significantly based on community feedback. The jQuery team is the ultimate determiner on what happens with the templating proposal – they might include it in jQuery core, or make it an official plugin, or reject it entirely. My team is excited to be able to participate in the open source process, and make suggestions and contributions the same way as any other member of the community. jQuery Template Support Client-side templates enable jQuery developers to easily generate and render HTML UI on the client. Templates support a simple syntax that enables either developers or designers to declaratively specify the HTML they want to generate. Developers can then programmatically invoke the templates on the client, and pass JavaScript objects to them to make the content rendered completely data driven. These JavaScript objects can optionally be based on data retrieved from a server. Because the jQuery templating proposal is still evolving in response to community feedback, the final version might look very different than the version below. This blog post gives you a sense of how you can try out and use templating as it exists today (you can download the prototype by the jQuery core team at http://github.com/jquery/jquery-tmpl or the latest submission from my team at http://github.com/nje/jquery-tmpl). jQuery Client Templates You create client-side jQuery templates by embedding content within a <script type="text/html"> tag. For example, the HTML below contains a <div> template container, as well as a client-side jQuery “contactTemplate” template (within the <script type="text/html"> element) that can be used to dynamically display a list of contacts: The {{= name }} and {{= phone }} expressions are used within the contact template above to display the names and phone numbers of “contact” objects passed to the template. We can use the template to display either an array of JavaScript objects or a single object. The JavaScript code below demonstrates how you can render a JavaScript array of “contact” object using the above template. The render() method renders the data into a string and appends the string to the “contactContainer” DIV element: When the page is loaded, the list of contacts is rendered by the template. All of this template rendering is happening on the client-side within the browser: Templating Commands and Conditional Display Logic The current templating proposal supports a small set of template commands - including if, else, and each statements. The number of template commands was deliberately kept small to encourage people to place more complicated logic outside of their templates. Even this small set of template commands is very useful though. Imagine, for example, that each contact can have zero or more phone numbers. The contacts could be represented by the JavaScript array below: The template below demonstrates how you can use the if and each template commands to conditionally display and loop the phone numbers for each contact: If a contact has one or more phone numbers then each of the phone numbers is displayed by iterating through the phone numbers with the each template command: The jQuery team designed the template commands so that they are extensible. If you have a need for a new template command then you can easily add new template commands to the default set of commands. Support for Client Data-Linking The ASP.NET team recently submitted another proposal and prototype to the jQuery forums (http://forum.jquery.com/topic/proposal-for-adding-data-linking-to-jquery). This proposal describes a new feature named data linking. Data Linking enables you to link a property of one object to a property of another object - so that when one property changes the other property changes. Data linking enables you to easily keep your UI and data objects synchronized within a page. If you are familiar with the concept of data-binding then you will be familiar with data linking (in the proposal, we call the feature data linking because jQuery already includes a bind() method that has nothing to do with data-binding). Imagine, for example, that you have a page with the following HTML <input> elements: The following JavaScript code links the two INPUT elements above to the properties of a JavaScript “contact” object that has a “name” and “phone” property: When you execute this code, the value of the first INPUT element (#name) is set to the value of the contact name property, and the value of the second INPUT element (#phone) is set to the value of the contact phone property. The properties of the contact object and the properties of the INPUT elements are also linked – so that changes to one are also reflected in the other. Because the contact object is linked to the INPUT element, when you request the page, the values of the contact properties are displayed: More interesting, the values of the linked INPUT elements will change automatically whenever you update the properties of the contact object they are linked to. For example, we could programmatically modify the properties of the “contact” object using the jQuery attr() method like below: Because our two INPUT elements are linked to the “contact” object, the INPUT element values will be updated automatically (without us having to write any code to modify the UI elements): Note that we updated the contact object above using the jQuery attr() method. In order for data linking to work, you must use jQuery methods to modify the property values. Two Way Linking The linkBoth() method enables two-way data linking. The contact object and INPUT elements are linked in both directions. When you modify the value of the INPUT element, the contact object is also updated automatically. For example, the following code adds a client-side JavaScript click handler to an HTML button element. When you click the button, the property values of the contact object are displayed using an alert() dialog: The following demonstrates what happens when you change the value of the Name INPUT element and click the Save button. Notice that the name property of the “contact” object that the INPUT element was linked to was updated automatically: The above example is obviously trivially simple. Instead of displaying the new values of the contact object with a JavaScript alert, you can imagine instead calling a web-service to save the object to a database. The benefit of data linking is that it enables you to focus on your data and frees you from the mechanics of keeping your UI and data in sync. Converters The current data linking proposal also supports a feature called converters. A converter enables you to easily convert the value of a property during data linking. For example, imagine that you want to represent phone numbers in a standard way with the “contact” object phone property. In particular, you don’t want to include special characters such as ()- in the phone number - instead you only want digits and nothing else. In that case, you can wire-up a converter to convert the value of an INPUT element into this format using the code below: Notice above how a converter function is being passed to the linkFrom() method used to link the phone property of the “contact” object with the value of the phone INPUT element. This convertor function strips any non-numeric characters from the INPUT element before updating the phone property. Now, if you enter the phone number (206) 555-9999 into the phone input field then the value 2065559999 is assigned to the phone property of the contact object: You can also use a converter in the opposite direction also. For example, you can apply a standard phone format string when displaying a phone number from a phone property. Combining Templating and Data Linking Our goal in submitting these two proposals for templating and data linking is to make it easier to work with data when building websites and applications with jQuery. Templating makes it easier to display a list of database records retrieved from a database through an Ajax call. Data linking makes it easier to keep the data and user interface in sync for update scenarios. Currently, we are working on an extension of the data linking proposal to support declarative data linking. We want to make it easy to take advantage of data linking when using a template to display data. For example, imagine that you are using the following template to display an array of product objects: Notice the {{link name}} and {{link price}} expressions. These expressions enable declarative data linking between the SPAN elements and properties of the product objects. The current jQuery templating prototype supports extending its syntax with custom template commands. In this case, we are extending the default templating syntax with a custom template command named “link”. The benefit of using data linking with the above template is that the SPAN elements will be automatically updated whenever the underlying “product” data is updated. Declarative data linking also makes it easier to create edit and insert forms. For example, you could create a form for editing a product by using declarative data linking like this: Whenever you change the value of the INPUT elements in a template that uses declarative data linking, the underlying JavaScript data object is automatically updated. Instead of needing to write code to scrape the HTML form to get updated values, you can instead work with the underlying data directly – making your client-side code much cleaner and simpler. Downloading Working Code Examples of the Above Scenarios You can download this .zip file to get with working code examples of the above scenarios. The .zip file includes 4 static HTML page: Listing1_Templating.htm – Illustrates basic templating. Listing2_TemplatingConditionals.htm – Illustrates templating with the use of the if and each template commands. Listing3_DataLinking.htm – Illustrates data linking. Listing4_Converters.htm – Illustrates using a converter with data linking. You can un-zip the file to the file-system and then run each page to see the concepts in action. Summary We are excited to be able to begin participating within the open-source jQuery project. We’ve received lots of encouraging feedback in response to our first two proposals, and we will continue to actively contribute going forward. These features will hopefully make it easier for all developers (including ASP.NET developers) to build great Ajax applications. Hope this helps, Scott P.S. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu]

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500 Metro Style WP7 Icons

- by Bil Simser

I was inspired by The Noun Project, a project that offers up “Metro-style” icons in SVG format. The project is licensed under a public domain license and while it’s a great project, all of the content is in SVG format. Jon Galloway has a great post (from 2007) talking about the differences between SVG and XAML so I highly recommend that for some background. I thought it would be helpful to the WPF/Windows Phone 7/Silverlight community to provide the content in alternative formats for use in your applications. The Goods I’ve put together a package of the 500 icons (502 actually) in PNG, XAML and the original SVG format along with a couple of sample projects so you can see them in action. There’s a WPF desktop app: And a Windows Phone 7 app: Building It To get all the content first I wrote up a quick program to suck the original SVG files. Luckily they’re all in a common path just named 1.SVG, 2.SVG, and so on. Easy sleazy to grab the contents. Once I had 500 SVG files I used the latest copy of XamlTune, an open source CodePlex project that has a command line conversion tool to convert the directory of SVG files into XAML (the tool also created a PNG file of each SVG so that’s just icing on the cake). Conversions The conversion from SVG to XAML isn’t 100%. While you can just drop the content into a WPF app, it doesn’t work that way for WP7. There are just some small adjustments I made to each format so you’ll have to do the same. Follow the information below or refer to the sample applications. As a sample, here’s an icon we want to use: Here’s the original SVG file: <svg version="1.0" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" width="100px" height="94.616px" viewBox="0 0 100 94.616" enable-background="new 0 0 100 94.616" xml:space="preserve"> <path d="M25.076,15.639c4.324,0.009,7.824-3.488,7.82-7.82C32.9,3.512,29.4,0.012,25.076,0c-4.313,0.012-7.814,3.512-7.821,7.819 C17.262,12.15,20.763,15.648,25.076,15.639L25.076,15.639z"/> <path d="M4.593,43.388h6.861l4.137-15.135h1.716L13.22,43.388h24.318l-4.389-15.135h1.817l2.32,7.415 c1.08,3.131,3.852,3.851,6.003,1.162l8.375-10.142c2.651-3.42-2.104-7.021-4.844-4.035l-4.993,5.952 c0.007,0.095-0.96-3.278-0.96-3.278c-1.135-3.978-4.918-7.903-10.595-7.922H19.576c-5.071,0.019-9.043,4.434-9.888,7.214 L4.593,43.388L4.593,43.388z"/> <polygon points="56.206,22.753 56.206,7.163 49.192,7.163 49.192,22.753 56.206,22.753 "/> <path d="M79.87,15.738c4.332-0.014,7.831-3.516,7.82-7.82c0.011-4.332-3.488-7.833-7.82-7.82c-4.306-0.013-7.806,3.488-7.821,7.82 C72.064,12.222,75.564,15.725,79.87,15.738L79.87,15.738z"/> <path d="M89.759,89.556v-43.19h5.751V22.804c0.007-3.079-2.757-5.448-6.71-5.449H70.436c-3.65,0.001-4.539,1.186-5.551,2.168 L49.597,37.889c-3.098,3.848,2.428,8.333,5.55,4.743L69.88,25.226v64.43c-0.019,6.475,9.06,6.686,9.081,0.201v-36.58h1.765v36.379 C80.748,96.109,89.772,96.13,89.759,89.556L89.759,89.556z"/> <polygon points="100,54.035 100,45.155 0,45.155 0,54.035 100,54.035 "/> </svg> Here’s the XAML that XamlTune created. It can be used in any WPF app without any changes: <Canvas Name="Layer_1" Width="100" Height="94.616" ClipToBounds="True" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M25.076,15.639C29.4,15.648 32.9,12.151 32.896,7.819 32.9,3.512 29.4,0.012 25.076,0 20.763,0.012 17.262,3.512 17.255,7.819 17.262,12.15 20.763,15.648 25.076,15.639L25.076,15.639z" /> </Path.Data> </Path> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M4.593,43.388L11.454,43.388 15.591,28.253 17.307,28.253 13.22,43.388 37.538,43.388 33.149,28.253 34.966,28.253 37.286,35.668C38.366,38.799,41.138,39.519,43.289,36.83L51.664,26.688C54.315,23.268,49.56,19.667,46.82,22.653L41.827,28.605C41.834,28.7 40.867,25.327 40.867,25.327 39.732,21.349 35.949,17.424 30.272,17.405L19.576,17.405C14.505,17.424,10.533,21.839,9.688,24.619L4.593,43.388 4.593,43.388z" /> </Path.Data> </Path> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M56.206,22.753L56.206,7.163 49.192,7.163 49.192,22.753 56.206,22.753z" /> </Path.Data> </Path> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M79.87,15.738C84.202,15.724 87.701,12.222 87.69,7.918 87.701,3.586 84.202,0.0849999999999991 79.87,0.097999999999999 75.564,0.084999999999999 72.064,3.586 72.049,7.918 72.064,12.222 75.564,15.725 79.87,15.738L79.87,15.738z" /> </Path.Data> </Path> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M89.759,89.556L89.759,46.366 95.51,46.366 95.51,22.804C95.517,19.725,92.753,17.356,88.8,17.355L70.436,17.355C66.786,17.356,65.897,18.541,64.885,19.523L49.597,37.889C46.499,41.737,52.025,46.222,55.147,42.632L69.88,25.226 69.88,89.656C69.861,96.131,78.94,96.342,78.961,89.857L78.961,53.277 80.726,53.277 80.726,89.656C80.748,96.109,89.772,96.13,89.759,89.556L89.759,89.556z" /> </Path.Data> </Path> <Path Fill="#FF000000"> <Path.Data> <PathGeometry FillRule="Nonzero" Figures="M100,54.035L100,45.155 0,45.155 0,54.035 100,54.035z" /> </Path.Data> </Path> </Canvas> The XAML works AS-IS in a WPF application but there are some changes I did to get it to work in a WP7 app. Here’s the modified XAML in a WP7 application: <Canvas Grid.Row="0" Grid.Column="0" Name="Icon_1" Width="100" Height="94.616"> <Path Fill="#FF000000" Data="M25.076,15.639C29.4,15.648 32.9,12.151 32.896,7.819 32.9,3.512 29.4,0.012 25.076,0 20.763,0.012 17.262,3.512 17.255,7.819 17.262,12.15 20.763,15.648 25.076,15.639L25.076,15.639z"> </Path> <Path Fill="#FF000000" Data="M4.593,43.388L11.454,43.388 15.591,28.253 17.307,28.253 13.22,43.388 37.538,43.388 33.149,28.253 34.966,28.253 37.286,35.668C38.366,38.799,41.138,39.519,43.289,36.83L51.664,26.688C54.315,23.268,49.56,19.667,46.82,22.653L41.827,28.605C41.834,28.7 40.867,25.327 40.867,25.327 39.732,21.349 35.949,17.424 30.272,17.405L19.576,17.405C14.505,17.424,10.533,21.839,9.688,24.619L4.593,43.388 4.593,43.388z"> </Path> <Path Fill="#FF000000" Data="M56.206,22.753L56.206,7.163 49.192,7.163 49.192,22.753 56.206,22.753z"> </Path> <Path Fill="#FF000000" Data="M79.87,15.738C84.202,15.724 87.701,12.222 87.69,7.918 87.701,3.586 84.202,0.0849999999999991 79.87,0.097999999999999 75.564,0.084999999999999 72.064,3.586 72.049,7.918 72.064,12.222 75.564,15.725 79.87,15.738L79.87,15.738z"> </Path> <Path Fill="#FF000000" Data="M89.759,89.556L89.759,46.366 95.51,46.366 95.51,22.804C95.517,19.725,92.753,17.356,88.8,17.355L70.436,17.355C66.786,17.356,65.897,18.541,64.885,19.523L49.597,37.889C46.499,41.737,52.025,46.222,55.147,42.632L69.88,25.226 69.88,89.656C69.861,96.131,78.94,96.342,78.961,89.857L78.961,53.277 80.726,53.277 80.726,89.656C80.748,96.109,89.772,96.13,89.759,89.556L89.759,89.556z"> </Path> <Path Fill="#FF000000" Data="M100,54.035L100,45.155 0,45.155 0,54.035 100,54.035z"> </Path> </Canvas> All I did was take the data portion and put it directly into a Data attribute on the Path. Note that while it does show up in the app (on the emulator or device) it wouldn’t show up in Visual Studio for me. Maybe some XAML guru out there can tell me why. You can just as easily use the PNG files in WP7 but if you want the crispness of vector graphics, go for the XAML version. Of course with XamlTune being open source you could always modify the output of that program to cater it to your app. If you do make a change that’s worthy please consider submitting a patch to the project so everyone can benefit. Hope this helps and happy programming! Resources and Links Sample Project and Icons XamlTune an open source project to convert SVG to XAML The Noun Project source of the original files Jon Galloways post on SVG and XAML StackOverflow question on converting SVG to XAML

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A Taxonomy of Numerical Methods v1

- by JoshReuben

Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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Day 2 - Game Design Documentation

- by dapostolov

So yesterday I didn't cut any code for my game but I was able to do a tiny bit of research on the XNA Game Development Technology and the communities out there and do you know what? I feel I'm a bit closer to my goal. The bad news is today I didn't cut code either. However, not all is lost because I wanted to get my ideas on paper and today I just did that. Today, I began to jot down notes about the game and how I felt the visual elements would interact with each other. Unlike my workplace, my personal level of documentation is nothing more than a task list or a mind map of my ideas; it helps me streamline my solutions quiet effectively and circumvent the long process of articulating each thought to the n-th degree. I truly dislike documentation (because I have an extremely hard time articulating my thought and solutions); however, because I tend to do a really good job with documentation I tend to get stuck writing the buggers. But as a generalist remark: 'No Developer likes documentation.' For now let's stick with my basic notes and call this post a living document. Here are my notes, fresh, from after watching the new first episode of Merlin second season! Actually, a quick recommendation to anyone who is reading this (if anyone is): I truly recommend you envelope yourself in the medium or task you're trying to tackle. Be one with moment and feel it! For instance: Are you writing a fantasy script / game? What would the music of the genre sound like? For me the Conan the Barbarian soundtrack by Basil Poledouris is frackin awesome. There are many other good CD's out there, which I listen to (some who even use medival instruments, but Conan I keep returning to. It's a creative trigger for me. Ask yourself what would the imagery look like? Time to surf google for artist renditions of fantasy! What would the game feel like? Start playing some of your favorite games that inspire you, be wary though, have some self control and don't let it absorb your time. Anyhow, onto the documentation... Screens, Scenes, and Sprites. Oh My! (groan...) The first thing that came to mind were the screens, I thought the following would suffice: Menu Screen Character Customisation Screen Loading Screen? Battle Ground The Menu Screen Ok. So, the thought here is when the game loads a huge title is displayed: Wizard Wars. The player is prompted with 3 menu items: 1 Player Game, 2 Player Game, and Exit. Since I'm targetting the PC platform, as a non-networked game to start, I picture myself running my mouse over each menu option and the visual element of the menu item changes, along with a sound to indicate that I am over a curent menu item. And as I move my mouse away, it changes back, and possibly an exit mouse sound. Maybe on the screen somewhere is a brazier alit with a magical tome open right beside it, OR, maybe the tome is the menu! I hear the menu music as mellow, not obtrusive or piercing. On a menu item select, a confirmation sound bellows to indicate the players selection. The Esc key will always return me to the previous screens or desktop. The menu screen must feel...dark, like a really important ritual is about to happen and thus the music should build up. 1 Player Game - > Customize Character(s) 2 Player Game - > Customize Character(s) Exit - > Back to Windows Notes: So the first thing I pick up here are a couple things: First and foremost, my artistic abilities suck crap, so I may have to hire an artist (now that i've said that, lets get techy) graphical objects will be positioned within a scene on each screen / window. Menu items will be represented grapically, possibly animated, and have sound / animation effects triggered by user input or a time line. I have an animated scene involving a brazier or fire on a stick IF I was to move this game to the xbox, I'd have to track which menu item is currently selected (unless I do a mouse pointer type thing.) WindowObject has a scene A Scene has many GameObjects GameObject has a position graphic or animation MenuObject is a GameObject which has a mouse in, mouse out, and click event which either does something graphically (animation), does something with sound, or moves to another screen. Character Customisation Screen With either the 1 or 2 player option selected, both selections will come to this screen; a wizard requires a name, powers, and vestements of course! Player one will configure his character first and then player two. I considered a split screen for PC but to have two people fighting over a keyboard would probably suck. For XBox, a split screen could work; maybe when I get into the networking portion (phase 2 blog?) of this game I will remove the 2 player option for PC and provide only multiplayer and I will leave 2 player for xbox...hmm... Anyhow...I picture the creation process as follows: Name: (textbox / keyboard entry) - for xbox, this would have to be different. Robe Color: (color box, or something) Stats: Speed, Oomph, and Health. (as sliders) 1 as minimum and 10 as maximum. Ok, Back, and Cancel buttons / options. Each stat has a benefit which are listed below. The idea is the player decides if he wants his wizard to run fast, be a tank and ... hit with a purse.Regardless, the player will have a pool of 12 points to use. Ideally, A balanced wizard will have 5 in each attribute. Spells? The only spell of choice is a ball of fire which comes without question. The music and screen should still feel like a ritual. The Character Speed Basically, how fast your character moves and casts. Oomph (Best Monster Truck Voice): PURE POWAH!!! The damage output of your fireball. Health How much damage you can take. Notes: I realise the game dynamics may sound uninteresting at the moment; but I think after a couple releases, we could have some other grand ideas such as: saved profiles, gold to upgrade arsenal of spells, talents, etc...but for now...a vanilla fireball thrower mage will suffice for this experiment. OK. So... a MenuObject may need to be loosely coupled to allow future items such as networking? may be a button? a CharacterObject has a name speed oomph health and a funky robe color. cap on the three stats (1-10) an arsenal of 1 spell (possibly could expand this) The Loading Screen As is. The Battleground Screen For now, I'm keeping the screen as max resolution for the PC. The screen isn't going to move or even be a split screen. I'm not aiming high here because I want to see what level of change is involved when new features / concepts are added to game content. I'm interested to find out if we could apply techniques such as MVC or MVVM to this type of development or is it too tightly coupled? This reminds me when when my best friend and I were brainstorming our game idea (this is going back a while...1994, 6?) and he cringed at the thought of bringing business technology into games, especially when I suggested a database to store character information and COM / DCOM as the medium, but it seems I wasn't far off (reflecting); just like his implementation of a xml "config file" for dynamic direct-x menus back before .net in 1999...anyhow...i digress... The Battle One screen, two characters lobing balls of fire at each other...It doesn't get better than that. Every so often a scroll appears...and the fireballs bounce off walls, or the wizard has rapid fire, or even scrolls of healing! The scroll options are endless. Two bars at the top, each the color of the wizard (with their name beside the bar) indicate how much health they have. Possibly the appearance of the scrolls means the battle is taking too long? I'm thinking 1 player controls: up, down, left, right and space to fire the button. Or even possibly, mouse click and shift - mouse button to fire a spell in the direction they are facing. Two player controls: a, s, d, f and space AND arrows (up, down, left, right) and Del key or Crtl. The game ends when a player has 0 health and a dialog box appears asking for a rematch / reconfigure / exit. Health goes down when a fireball (friendly or not), connects with a wizard. When a wizard connects with a scroll, a countdown clock / icon appears near the health bar and the wizard begins to glow. For the most part, a wizard can have only scroll 1 effect on him at a time. Notes: Ok, there's alot to cover here. a CharacterObject is a GameObject it travels at a set velocity it travels in a direction it has sounds (walking, running, casting, impact, dying, laughing, whistling, other?) it has animations (walking, running, casting, impact, dying, laughing, idle, other?) it has a lifespan (determined by health) it is alive or dead it has a position a ScrollObject is a GameObject it carries a transferance of points "damage" (or healing, bad scroll effect?) (determinde by caster) it carries a transferance of "other" it is stationary it has a sound on impact it has a stationary animation it has an impact animation / or transfers an impact animation it has a fade animation? it has a lifespan (determined by game) it is alive or dead it has a position a WallObject is a GameObject it has a sound on fireball impact? it is a still image / stationary it has an impact animation / or transfers an impact animation it is dead it has a position A FireBall is a GameObject it carries a transferance of poinst "damage" (or healing, bad scroll effect?) (determinde by caster) it travels at a set velocity it travels in a direction it has a sound it has a travel animation it has an impact animation / or transfers an impact animation it has a fade animation? it has a lifespan (determined by caster) it is alive or dead it has a position As I look at this, I can see some common attributes in each object that I can carry up to the GameObject. I think I'm going to end the documentation here, it's taken me a bit of time to type this all out, tomorrow. I'll load up my IDE and my paint studio to get some good old fashioned cowboy hacking going! D.

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