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• How to manage maintenance/bug-fix branches in Subversion when third-party installers are involved?

  - by Mike Spross

  We have a suite of related products written in VB6, with some C# and VB.NET projects, and all the source is kept in a single Subversion repository. We haven't been using branches in Subversion (although we do tag releases now), and simply do all development in trunk, creating new releases when the trunk is stable enough. This causes no end of grief when we release a new version, issues are found with it, and we have already begun working on new features or major changes to the trunk. In the past, we would address this in one of two ways, depending on the severity of the issues and how stable we thought the trunk was: Hurry to stabilize the trunk, fix the issues, and then release a maintenance update based on the HEAD revision, but this had the side effect of releases that fixed the bugs but introduced new issues because of half-finished features or bugfixes that were in trunk. Make customers wait until the next official release, which is usually a few months. We want to change our policies to better deal with this situation. I was considering creating a "maintenance branch" in Subversion whenever I tag an official release. Then, new development would continue in trunk, and I can periodically merge specific fixes from trunk into the maintenance branch, and create a maintenance release when enough fixes are accumulated, while we continue to work on the next major update in parallel. I know we could also have a more stable trunk and create a branch for new updates instead, but keeping current development in trunk seems simpler to me. The major problem is that while we can easily branch the source code from a release tag and recompile it to get the binaries for that release, I'm not sure how to handle the setup and installer projects. We use QSetup to create all of our setup programs, and right now when we need to modify a setup project, we just edit the project file in-place (all the setup projects and any dependencies that we don't compile ourselves are stored on a separate server, and we make sure to always compile the setup projects on that machine only). However, since we may add or remove files to the setup as our code changes, there is no guarantee that today's setup projects will work with yesterday's source code. I was going to put all the QSetup projects in Subversion to deal with this, but I see some problems with this approach. I want the creation of setup programs to be as automated as possible, and at the very least, I want a separate build machine where I can build the release that I want (grabbing the code from Subversion first), grab the setup project for that release from Subversion, recompile the setup, and then copy the setup to another place on the network for QA testing and eventual release to customers. However, when someone needs to change a setup project (to add a new dependency that trunk now requires or to make other changes), there is a problem. If they treat it like a source file and check it out on their own machine to edit it, they won't be able to add files to the project unless they first copy the files they need to add to the build machine (so they are available to other developers), then copy all the other dependencies from the build machine to their machine, making sure to match the folder structure exactly. The issue here is that QSetup uses absolute paths for any files added to a setup project. However, this means installing a bunch of setup dependencies onto development machines, which seems messy (and which could destabilize the development environment if someone accidentally runs the setup project on their machine). Also, how do we manage third-party dependencies? For example, if the current maintenance branch used MSXML 3.0 and the trunk now requires MSXML 4.0, we can't go back and create a maintenance release if we have already replaced the MSXML library on the build machine with the latest version (assuming both versions have the same filename). The only solution I can think is to either put all the third-party dependencies in Subversion along with the source code, or to make sure we put different library versions in separate folders (i.e. C:\Setup\Dependencies\MSXML\v3.0 and C:\Setup\Dependencies\MSXML\v4.0). Is one way "better" or more common than the other? Are there any best practices for dealing with this situation? Basically, if we release v2.0 of our software, we want to be able to release v2.0.1, v2.0.2, and v.2.0.3 while we work on v2.1, but the whole setup/installation project and setup dependency issue is making this more complicated than the the typical "just create a branch in Subversion and recompile as needed" answer.

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• Part 3 of 4 : Tips/Tricks for Silverlight Developers.

  - by mbcrump

  Part 1 | Part 2 | Part 3 | Part 4 I wanted to create a series of blog post that gets right to the point and is aimed specifically at Silverlight Developers. The most important things I want this series to answer is : What is it?  Why do I care? How do I do it? I hope that you enjoy this series. Let’s get started: Tip/Trick #11) What is it? Underline Text in a TextBlock. Why do I care? I’ve seen people do some crazy things to get underlined text in a Silverlight Application. In case you didn’t know there is a property for that. How do I do it: On a TextBlock you have a property called TextDecorations. You can easily set this property in XAML or CodeBehind with the following snippet: <UserControl x:Class="SilverlightApplication19.MainPage" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400"> <Grid x:Name="LayoutRoot" Background="White"> <TextBlock Name="txtTB" Text="MichaelCrump.NET" TextDecorations="Underline" /> </Grid> </UserControl> or you can do it in CodeBehind… txtTB.TextDecorations = TextDecorations.Underline;   Tip/Trick #12) What is it? Get the browser information from a Silverlight Application. Why do I care? This will allow you to program around certain browser conditions that otherwise may not be aware of. How do I do it: It is very easy to extract Browser Information out a Silverlight Application by using the BrowserInformation class. You can copy/paste this code snippet to have access to all of them. string strBrowserName = HtmlPage.BrowserInformation.Name; string strBrowserMinorVersion = HtmlPage.BrowserInformation.BrowserVersion.Minor.ToString(); string strIsCookiesEnabled = HtmlPage.BrowserInformation.CookiesEnabled.ToString(); string strPlatform = HtmlPage.BrowserInformation.Platform; string strProductName = HtmlPage.BrowserInformation.ProductName; string strProductVersion = HtmlPage.BrowserInformation.ProductVersion; string strUserAgent = HtmlPage.BrowserInformation.UserAgent; string strBrowserVersion = HtmlPage.BrowserInformation.BrowserVersion.ToString(); string strBrowserMajorVersion = HtmlPage.BrowserInformation.BrowserVersion.Major.ToString(); Tip/Trick #13) What is it? Always check the minRuntimeVersion after creating a new Silverlight Application. Why do I care? Whenever you create a new Silverlight Application and host it inside of an ASP.net website you will notice Visual Studio generates some code for you as shown below. The minRuntimeVersion value is set by the SDK installed on your system. Be careful, if you are playing with beta’s like “Lightswitch” because you will have a higher version of the SDK installed. So when you create a new Silverlight 4 project and deploy it your customers they will get a prompt telling them they need to upgrade Silverlight. They also will not be able to upgrade to your version because its not released to the public yet. How do I do it: Open up the .aspx or .html file Visual Studio generated and look for the line below. Make sure it matches whatever version you are actually targeting. Tip/Trick #14) What is it? The VisualTreeHelper class provides useful methods for involving nodes in a visual tree. Why do I care? It’s nice to have the ability to “walk” a visual tree or to get the rendered elements of a ListBox. I have it very useful for debugging my Silverlight application. How do I do it: Many examples exist on the web, but say that you have a huge Silverlight application and want to find the parent object of a control.  In the code snippet below, we would get 3 MessageBoxes with (StackPanel first, Grid second and UserControl Third). This is a tiny application, but imagine how helpful this would be on a large project. <UserControl x:Class="SilverlightApplication18.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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400"> <Grid x:Name="LayoutRoot" Background="White"> <StackPanel> <Button Content="Button" Height="23" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" /> </StackPanel> </Grid> </UserControl> private void button1_Click(object sender, RoutedEventArgs e) { DependencyObject obj = button1; while ((obj = VisualTreeHelper.GetParent(obj)) != null) { MessageBox.Show(obj.GetType().ToString()); } } Tip/Trick #15) What is it? Add ChildWindows to your Silverlight Application. Why do I care? ChildWindows are a great way to direct a user attention to a particular part of your application. This could be used when saving or entering data. How do I do it: Right click your Silverlight Application and click Add then New Item. Select Silverlight Child Window as shown below. Add an event and call the ChildWindow with the following snippet below: private void button1_Click(object sender, RoutedEventArgs e) { ChildWindow1 cw = new ChildWindow1(); cw.Show(); } Your main application can still process information but this screen forces the user to select an action before proceeding. The code behind of the ChildWindow will look like the following: namespace SilverlightApplication18 { public partial class ChildWindow1 : ChildWindow { public ChildWindow1() { InitializeComponent(); } private void OKButton_Click(object sender, RoutedEventArgs e) { this.DialogResult = true; //TODO: Add logic to save what the user entered. } private void CancelButton_Click(object sender, RoutedEventArgs e) { this.DialogResult = false; } } } Thanks for reading and please come back for Part 4.  Subscribe to my feed CodeProject

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• Designing an API with compile-time option to remove first parameter to most functions and use a glob

  - by tomlogic

  I'm trying to design a portable API in ANSI C89/ISO C90 to access a wireless networking device on a serial interface. The library will have multiple network layers, and various versions need to run on embedded devices as small as an 8-bit micro with 32K of code and 2K of data, on up to embedded devices with a megabyte or more of code and data. In most cases, the target processor will have a single network interface and I'll want to use a single global structure with all state information for that device. I don't want to pass a pointer to that structure through the network layers. In a few cases (e.g., device with more resources that needs to live on two networks) I will interface to multiple devices, each with their own global state, and will need to pass a pointer to that state (or an index to a state array) through the layers. I came up with two possible solutions, but neither one is particularly pretty. Keep in mind that the full driver will potentially be 20,000 lines or more, cover multiple files, and contain hundreds of functions. The first solution requires a macro that discards the first parameter for every function that needs to access the global state: // network.h typedef struct dev_t { int var; long othervar; char name[20]; } dev_t; #ifdef IF_MULTI #define foo_function( x, a, b, c) _foo_function( x, a, b, c) #define bar_function( x) _bar_function( x) #else extern dev_t DEV; #define IFACE (&DEV) #define foo_function( x, a, b, c) _foo_function( a, b, c) #define bar_function( x) _bar_function( ) #endif int bar_function( dev_t *IFACE); int foo_function( dev_t *IFACE, int a, long b, char *c); // network.c #ifndef IF_MULTI dev_t DEV; #endif int bar_function( dev_t *IFACE) { memset( IFACE, 0, sizeof *IFACE); return 0; } int foo_function( dev_t *IFACE, int a, long b, char *c) { bar_function( IFACE); IFACE->var = a; IFACE->othervar = b; strcpy( IFACE->name, c); return 0; } The second solution defines macros to use in the function declarations: // network.h typedef struct dev_t { int var; long othervar; char name[20]; } dev_t; #ifdef IF_MULTI #define DEV_PARAM_ONLY dev_t *IFACE #define DEV_PARAM DEV_PARAM_ONLY, #else extern dev_t DEV; #define IFACE (&DEV) #define DEV_PARAM_ONLY void #define DEV_PARAM #endif int bar_function( DEV_PARAM_ONLY); // I don't like the missing comma between DEV_PARAM and arg2... int foo_function( DEV_PARAM int a, long b, char *c); // network.c #ifndef IF_MULTI dev_t DEV; #endif int bar_function( DEV_PARAM_ONLY) { memset( IFACE, 0, sizeof *IFACE); return 0; } int foo_function( DEV_PARAM int a, long b, char *c) { bar_function( IFACE); IFACE->var = a; IFACE->othervar = b; strcpy( IFACE->name, c); return 0; } The C code to access either method remains the same: // multi.c - example of multiple interfaces #define IF_MULTI #include "network.h" dev_t if0, if1; int main() { foo_function( &if0, -1, 3.1415926, "public"); foo_function( &if1, 42, 3.1415926, "private"); return 0; } // single.c - example of a single interface #include "network.h" int main() { foo_function( 11, 1.0, "network"); return 0; } Is there a cleaner method that I haven't figured out? I lean toward the second since it should be easier to maintain, and it's clearer that there's some macro magic in the parameters to the function. Also, the first method requires prefixing the function names with "_" when I want to use them as function pointers. I really do want to remove the parameter in the "single interface" case to eliminate unnecessary code to push the parameter onto the stack, and to allow the function to access the first "real" parameter in a register instead of loading it from the stack. And, if at all possible, I don't want to have to maintain two separate codebases. Thoughts? Ideas? Examples of something similar in existing code? (Note that using C++ isn't an option, since some of the planned targets don't have a C++ compiler available.)

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• jQuery doesn't work after an Ajax post

  - by user1758979

  I'm using jQuery to sort a list of entries, between <LI></LI> tags, and then an Ajax post to validate the order and 'update' the page with the content returned. $.ajax({url: "./test.php?id=<?php echo $id; ?>&action=modify", contenttype: "application/x-www-form-urlencoded;charset=utf-8", data: {myJson: data}, type: 'post', success: function(data) { $('html').html(data); OnloadFunction (); } }); Then, I lose the ability to sort the list (I'm not sure if clear...). I tried to move the content of the $(document).ready inside the OnloadFunction (), and call it with <script>OnloadFunction ();</script> inside the block dealing with the modifications to do : $action= $_GET['action']; if ($action == "modify") { // Code here } but it doesn't work... I can't figure out how to do that. Could anyone help ? I stripped out the main part of the code to keep only the essential (filename: test.php) <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <script type="text/javascript" src="jquery-1.8.2.min.js"></script> <script type="text/javascript" src="jquery-ui-1.9.0.custom.min.js"></script> <script> $(document).ready(function(){ //alert("I am ready"); OnloadFunction (); }); function OnloadFunction () { $(function() { $("#SortColumn ul").sortable({ opacity: 0.6, cursor: 'move', update: function() {} }); }); //alert('OnloadFunction ends'); } function valider(){ var SortedId = new Array(); SortIdNb = 0; $('#SortColumn ul li').each(function() { SortedId.push(this.id); }); var data = { /* Real code contains an array with the <li> id */ CheckedId: "CheckedId", SortedId: SortedId, }; data = JSON.stringify(data); $.ajax({url: "./test.php?id=<?php echo $id; ?>&action=modify", contenttype: "application/x-www-form-urlencoded;charset=utf-8", data: {myJson: data}, type: 'post', success: function(data) { //alert(data); $('html').html(data); OnloadFunction (); } }); } </script> </head> <body> <? $action= $_GET['action']; $id = $_GET['id']; if ($id == 0) {$id=1;} $id += 1; if ($action == "modify") { echo "action: modify<br>"; echo "id (àvèc aççént$): ".$id."<br>"; // "(àvèc aççént$)" to check characters because character set is incorrect after the ajax post $data = json_decode($_POST['myJson'], true); // PHP code here to treat the new list send via the post and update the database print_r($data); } ?> <!-- PHP code here to get the following list from the database --> <div id="SortColumn"> <ul> <li id="recordsArray_1">recordsArray_1</li> <li id="recordsArray_2">recordsArray_2</li> <li id="recordsArray_3">recordsArray_3</li> <li id="recordsArray_4">recordsArray_4</li> <li id="recordsArray_5">recordsArray_5</li> </ul> </div> <input type="button" value="Modifier" onclick="valider();"> </body> </html>

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• Is multithreading the right way to go for my case?

  - by Julien Lebosquain

  Hello, I'm currently designing a multi-client / server application. I'm using plain good old sockets because WCF or similar technology is not what I need. Let me explain: it isn't the classical case of a client simply calling a service; all clients can 'interact' with each other by sending a packet to the server, which will then do some action, and possible re-dispatch an answer message to one or more clients. Although doable with WCF, the application will get pretty complex with hundreds of different messages. For each connected client, I'm of course using asynchronous methods to send and receive bytes. I've got the messages fully working, everything's fine. Except that for each line of code I'm writing, my head just burns because of multithreading issues. Since there could be around 200 clients connected at the same time, I chose to go the fully multithreaded way: each received message on a socket is immediately processed on the thread pool thread it was received, not on a single consumer thread. Since each client can interact with other clients, and indirectly with shared objects on the server, I must protect almost every object that is mutable. I first went with a ReaderWriterLockSlim for each resource that must be protected, but quickly noticed that there are more writes overall than reads in the server application, and switched to the well-known Monitor to simplify the code. So far, so good. Each resource is protected, I have helper classes that I must use to get a lock and its protected resource, so I can't use an object without getting a lock. Moreover, each client has its own lock that is entered as soon as a packet is received from its socket. It's done to prevent other clients from making changes to the state of this client while it has some messages being processed, which is something that will happen frequently. Now, I don't just need to protect resources from concurrent accesses. I must keep every client in sync with the server for some collections I have. One tricky part that I'm currently struggling with is the following: I have a collection of clients. Each client has its own unique ID. When a client connects, it must receive the IDs of every connected client, and each one of them must be notified of the newcomer's ID. When a client disconnects, every other client must know it so that its ID is no longer valid for them. Every client must always have, at a given time, the same clients collection as the server so that I can assume that everybody knows everybody. This way if I'm sending a message to client #1 telling "Client #2 has done something", I know that it will always be correctly interpreted: Client 1 will never wonder "but who is Client 2 anyway?". My first attempt for handling the connection of a new client (let's call it X) was this pseudo-code (remember that newClient is already locked here): lock (clients) { foreach (var client in clients) { lock (client) { client.Send("newClient with id X has connected"); } } clients.Add(newClient); newClient.Send("the list of other clients"); } Now imagine that in the same time, another client has sent a packet that translates into a message that must be broadcasted to every connected client, the pseudo-code will be something like this (remember that the current client - let's call it Y - is already locked here): lock (clients) { foreach (var client in clients) { lock (client) { client.Send("something"); } } } An obvious deadlock occurs here: on one thread X is locked, the clients lock has been entered, started looping through the clients, and at one moment must get Y's lock... which is already acquired on the second thread, itself waiting for the clients collection lock to be released! This is not the only case like this in the server application. There are other collections which must be kept in sync with the clients, some properties on a client can be changed by another one, etc. I tried other types of locks, lock-free mechanisms and a bunch of other things. Either there were obvious deadlocks when I'm using too much locks for safety, or obvious race conditions otherwise. When I finally find a good middle point between the two, it usually comes with very subtle race conditions / dead locks and other multi-threading issues... my head hurts very quickly since for any single line of code I'm writing I have to review almost the whole application to ensure everything will behave correctly with any number of threads. So here's my final question: how would you resolve this specific case, the general case, and more importantly: aren't I going the wrong way here? I have little problems with the .NET framework, C#, simple concurrency or algorithms in general. Still, I'm lost here. I know I could use only one thread processing the incoming requests and everything will be fine. However, that won't scale well at all with more clients... But I'm thinking more and more to go this simple way. What do you think? Thanks in advance to you, StackOverflow people which have taken the time to read this huge question. I really had to explain the whole context if I want to get some help.

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• how can we generate the bit greater than 60000?

  - by thinthinyu

  we can now generate about 50000bits. my code cannot generate more than 60000 bit..please help me............m_B is member variable and type is CString. // LFSR_ECDlg.cpp : implementation file // #include "stdafx.h" #include "myecc.h" #include "LFSR_ECDlg.h" #include "MyClass.h" #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif extern MyClass mycrv; ///////////////////////////////////////////////////////////////////////////// // LFSR_ECDlg dialog LFSR_ECDlg::LFSR_ECDlg(CWnd* pParent /*=NULL*/) : CDialog(LFSR_ECDlg::IDD, pParent) { //{{AFX_DATA_INIT(LFSR_ECDlg) m_C1 = 0; m_C2 = 0; m_B = _T(""); m_p = _T(""); m_Qty = 0; m_time = _T(""); //}}AFX_DATA_INIT } void LFSR_ECDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(LFSR_ECDlg) DDX_Text(pDX, IDC_C1, m_C1); DDX_Text(pDX, IDC_C2, m_C2); DDX_Text(pDX, IDC_Sequence, m_B); DDX_Text(pDX, IDC_Sequence2, m_p); DDX_Text(pDX, IDC_QTY, m_Qty); DDV_MinMaxLong(pDX, m_Qty, 0, 2147483647); DDX_Text(pDX, IDC_time, m_time); //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(LFSR_ECDlg, CDialog) //{{AFX_MSG_MAP(LFSR_ECDlg) ON_WM_SETCURSOR() ON_EN_CHANGE(IDC_Sequence, OnGeneratorLFSR) ON_MESSAGE(WM_MYPAINTMESSAGE,PaintMyCaption)//by ttyu ON_BN_CLICKED(IDC_save, Onsave) //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // LFSR_ECDlg message handlers bool LFSR_ECDlg::CheckDataEntry() { //if((m_Px>=mycrv.p)|(m_Py>=mycrv.p)) {AfxMessageBox("Seed [P] is invalid!");return false;}//by ttyu if((m_C1<=0) | (m_C1>mycrv.n)) {AfxMessageBox("Constant c1 is not valid!");return false;} if((m_C2<=0 )| (m_C2>mycrv.n)) {AfxMessageBox("Constant c2 is not valid!");return false;} return true; } void LFSR_ECDlg::OnOK() { UpdateData(true); static int stime,etime,dtime; CString txt; m_time=""; CTime t(CTime::GetCurrentTime()); CString txt1; txt1=""; //ms = t.GetDay(); // TODO: Add extra validation here stime=t.GetTime(); txt1.Format("%d",stime); AfxMessageBox (txt1); txt=""; if (CheckDataEntry()) OnGeneratorLFSR(); etime=t.GetTime(); CString txt2; txt2=""; txt2.Format("%d",etime); AfxMessageBox (txt2); dtime=etime-stime; txt.Format("%f",dtime); m_time+=txt; // UpdateData(false); //rtime.Format("%s, %s %d, %d.",day,month,dd,yy); //CDialog::OnOK(); } void LFSR_ECDlg::OnCancel() { // TODO: Add extra cleanup here CDialog::OnCancel(); } void LFSR_ECDlg::OnGeneratorLFSR() { // TODO: If this is a RICHEDIT control, the control will not // send this notification unless you override the CDialog::OnInitDialog() // function and call CRichEditCtrl().SetEventMask() // with the ENM_CHANGE flag ORed into the mask. // TODO: Add your control notification handler code here point P0,P1,P2; P0 = mycrv.G; P1 = mycrv.MulPoint(P0,2); int C1=m_C1, C2=m_C2, n=m_Qty, k=0; int q= (mycrv.p-1) / 2; m_p = ""; m_B = ""; CString txt; for(int i=0;i<n;i++) { txt=""; if(P0==mycrv.O) txt.Format("O"); else txt.Format("(%d, %d)",P0.x,P0.y); m_p +=txt; m_p += 13; m_p += 10; if((P0.y >= 0)&&(P0.y <= q)) m_B += "0"; else if(P0 == mycrv.O) m_B += "0"; else m_B += "1"; //m_B += 13;//by ttyu // m_B += 10;//by ttyu P2 = mycrv.AddPoints(mycrv.MulPoint(P1,C2), mycrv.MulPoint(P0,C1)); P0 = P1; P1 = P2; } } BOOL LFSR_ECDlg::OnInitDialog() { CDialog::OnInitDialog(); // TODO: Add extra initialization here //code for dlg bar CString str="LFSR_EC"; m_cap.SetCaption (str); m_cap.Install (this,WM_MYPAINTMESSAGE); ////////////////////////////// return TRUE; // return TRUE unless you set the focus to a control // EXCEPTION: OCX Property Pages should return FALSE } LRESULT LFSR_ECDlg::PaintMyCaption(WPARAM wp, LPARAM lp) { m_cap.PaintCaption(wp,lp); return 0; } BOOL LFSR_ECDlg::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message) { // TODO: Add your message handler code here and/or call default return CDialog::OnSetCursor(pWnd, nHitTest, message); } void LFSR_ECDlg::Onsave() { this->UpdateData(); CFile bitstream; char strFilter[] = { "Stream Records (*.mpl)|*.mpl| (*.pis)|*.pis|All Files (*.*)|*.*||" }; CFileDialog FileDlg(FALSE, ".mpl", NULL, 0, strFilter); //insertion//by TTT CFile cf_object; if( FileDlg.DoModal() == IDOK ){ cf_object.Open( FileDlg.GetFileName(), CFile::modeCreate|CFile::modeWrite); //char szText[100]; //strcpy(szText, "File Write Test"); CString txt; txt=""; txt.Format("%s",m_B);//by ANO AfxMessageBox (txt);//by ANO int mB_size=m_B.GetLength(); cf_object.Write (m_B,mB_size); //insertion end /* if( FileDlg.DoModal() == IDOK ) { if( bitstream.Open(FileDlg.GetFileName(), CFile::modeCreate | CFile::modeWrite) == FALSE ) return; CArchive ar(&bitstream, CArchive::store); CString txt; txt=""; txt.Format("%s",m_B);//by ANO AfxMessageBox (txt);//by ANO //txt=m_B;//by ANO ar <<txt;//by ANO ar.Close(); } else return; bitstream.Close(); */ // TODO: Add your control notification handler code here } }

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• Silverlight 4 Twitter Client &ndash; Part 3

  - by Max

  Finally Silverlight 4 RC is released and also that Windows 7 Phone Series will rely heavily on Silverlight platform for apps platform. its a really good news for Silverlight developers and designers. More information on this here. You can use SL 4 RC with VS 2010. SL 4 RC does not come with VS 2010, you need to download it separately and install it. So for the next part, be ready with VS 2010 and SL4 RC, we will start using them and not With this momentum, let us go to the next part of our twitter client tutorial. This tutorial will cover setting your status in Twitter and also retrieving your 1) As everything in Silverlight is asynchronous, we need to have some visual representation showing that something is going on in the background. So what I did was to create a progress bar with indeterminate animation. The XAML is here below. <ProgressBar Maximum="100" Width="300" Height="50" Margin="20" Visibility="Collapsed" IsIndeterminate="True" Name="progressBar1" VerticalAlignment="Center" HorizontalAlignment="Center" /> 2) I will be toggling this progress bar to show the background work. So I thought of writing this small method, which I use to toggle the visibility of this progress bar. Just pass a bool to this method and this will toggle it based on its current visibility status. public void toggleProgressBar(bool Option){ if (Option) { if (progressBar1.Visibility == System.Windows.Visibility.Collapsed) progressBar1.Visibility = System.Windows.Visibility.Visible; } else { if (progressBar1.Visibility == System.Windows.Visibility.Visible) progressBar1.Visibility = System.Windows.Visibility.Collapsed; }} 3) Now let us create a grid to hold a textbox and a update button. The XAML will look like something below <Grid HorizontalAlignment="Center"> <Grid.RowDefinitions> <RowDefinition Height="50"></RowDefinition> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="400"></ColumnDefinition> <ColumnDefinition Width="200"></ColumnDefinition> </Grid.ColumnDefinitions> <TextBox Name="TwitterStatus" Width="380" Height="50"></TextBox> <Button Name="UpdateStatus" Content="Update" Grid.Row="1" Grid.Column="2" Width="200" Height="50" Click="UpdateStatus_Click"></Button></Grid> 4) The click handler for this update button will be again using the Web Client to post values. Posting values using Web Client. The code is: private void UpdateStatus_Click(object sender, RoutedEventArgs e){ toggleProgressBar(true); string statusupdate = "status=" + TwitterStatus.Text; WebRequest.RegisterPrefix("https://", System.Net.Browser.WebRequestCreator.ClientHttp);  WebClient myService = new WebClient(); myService.AllowReadStreamBuffering = true; myService.UseDefaultCredentials = false; myService.Credentials = new NetworkCredential(GlobalVariable.getUserName(), GlobalVariable.getPassword());  myService.UploadStringCompleted += new UploadStringCompletedEventHandler(myService_UploadStringCompleted); myService.UploadStringAsync(new Uri("https://twitter.com/statuses/update.xml"), statusupdate);  this.Dispatcher.BeginInvoke(() => ClearTextBoxValue());} 5) In the above code, we have a event handler which will be fired on this request is completed – !! Remember SL is Asynch !! So in the myService_UploadStringCompleted, we will just toggle the progress bar and change some status text to say that its done. The code for this will be StatusMessage is just another textblock conveniently positioned in the page.  void myService_UploadStringCompleted(object sender, UploadStringCompletedEventArgs e){ if (e.Error != null) { StatusMessage.Text = "Status Update Failed: " + e.Error.Message.ToString(); } else { toggleProgressBar(false); TwitterCredentialsSubmit(); }} 6) Now let us look at fetching the friends updates of the logged in user and displaying it in a datagrid. So just define a data grid and set its autogenerate columns as true. 7) Let us first create a data structure for use with fetching the friends timeline. The code is something like below: namespace MaxTwitter.Classes{ public class Status { public Status() {} public string ID { get; set; } public string Text { get; set; } public string Source { get; set; } public string UserID { get; set; } public string UserName { get; set; } }} You can add as many fields as you want, for the list of fields, have a look at here. It will ask for your Twitter username and password, just provide them and this will display the xml file. Go through them pick and choose your desired fields and include in your Data Structure. 8) Now the web client request for this is similar to the one we saw in step 4. Just change the uri in the last but one step to https://twitter.com/statuses/friends_timeline.xml Be sure to change the event handler to something else and within that we will use XLINQ to fetch the required details for us. Now let us how this event handler fetches details. public void parseXML(string text){ XDocument xdoc; if(text.Length> 0) xdoc = XDocument.Parse(text); else xdoc = XDocument.Parse(@"I USED MY OWN LOCAL COPY OF XML FILE HERE FOR OFFLINE TESTING"); statusList = new List<Status>(); statusList = (from status in xdoc.Descendants("status") select new Status { ID = status.Element("id").Value, Text = status.Element("text").Value, Source = status.Element("source").Value, UserID = status.Element("user").Element("id").Value, UserName = status.Element("user").Element("screen_name").Value, }).ToList(); //MessageBox.Show(text); //this.Dispatcher.BeginInvoke(() => CallDatabindMethod(StatusCollection)); //MessageBox.Show(statusList.Count.ToString()); DataGridStatus.ItemsSource = statusList; StatusMessage.Text = "Datagrid refreshed."; toggleProgressBar(false);} in the event handler, we call this method with e.Result.ToString() Parsing XML files using LINQ is super cool, I love it.   I am stopping it here for  this post. Will post the completed files in next post, as I’ve worked on a few more features in this page and don’t want to confuse you. See you soon in my next post where will play with Twitter lists. Have a nice day! Technorati Tags: Silverlight,LINQ,XLINQ,Twitter API,Twitter,Network Credentials

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• Re-opening closed dialog puts it in the start position after moving it

  - by semmelbroesel

  I'm using multiple instances of the JQuery-UI dialog along with draggable and resizable. Whenever I drag or resize one of the dialog boxes, the position and dimensions of the current box are saved to a database and then loaded the next time the page opens. This is working well. However, when I close a dialog box and re-open it using a button, jQuery sets the position of the box back to its original location in the center of the screen. Furthermore, I use a show effect to slide the box off to the left on closing and in from the left on re-opening. I found two ways to update its position when the slide in animation is done, however, it still slides into the center of the screen, and I have yet to find a way to get it to slide in towards the location it is supposed to have. Here are the parts of the code that play a part in this: $('.box').dialog({ closeOnEscape: false, hide: { effect: "drop", direction: 'left' }, beforeClose: function (evt, ui){ var $this = $(this); SavePos($this); // saves the dimensions to db }, dragStop: function() { var $this = $(this); SavePos($this); }, resizeStop: function() { var $this = $(this); SavePos($this); }, open: function() { var $this = $(this); $this.dialog('option', { show: { effect: "drop", direction: 'left'} } ); if (init) // meaning only load this code when the page has finished initializing { // tried it both ways - set the position before and after the effect - no success UpdatePos($this.attr('id')); // I tried this section with promise() and effect / complete - I found no difference $this.parent().promise().done(function() { UpdatePos($this.attr('id')); }); } } }); function UpdatePos(key) { // boxpos is an object holding the position for each box by the box's id var $this = $('#' + key); //console.log('updating pos for box ' + boxid); if ($this && $this.hasClass('ui-dialog-content')) { //console.log($this.dialog('widget').css('left')); $this.dialog('option', { width: boxpos[key].width, height: boxpos[key].height }); $this.dialog('widget').css({ left: boxpos[key].left + 'px', top: boxpos[key].top + 'px' }); //console.log('finished updating pos'); //console.log($this.dialog('widget').css('left')); } } The button that re-opens the box has this code on it to make that happen: var $box = $('#boxid'); if ($box) { if ($box.dialog('isOpen')) { $box.dialog('moveToTop'); } else { $box.dialog("open") } } I don't know what jQuery-UI does to the box as it hides it (other than display:none) or to make it slide in, so maybe there's something I'm missing here that might help... Basically, I need JQuery to remember the box' position and put the box back into that location when it is re-opened. It took me days to make it this far, but this is one obstacle I have yet to overcome. Maybe there's a different way I can re-open the box? Thanks! EDIT: Forgot - this issue ONLY happens when I use my UpdatePos function to set the location of a box (i.e. on page load). When I drag a box with my mouse, close it, and re-open it, everything works. So I'm guessing there's one more storage location for the box' position that I'm missing here... EDIT2: After more messing with it, my code for debugging now looks like this: open: function() { var $this = $(this); console.log('box open'); console.log($this.dialog('widget').position()); // { top=0, left=-78.5} console.log($this.dialog('widget').css('left')); $this.dialog('option', { show: { effect: "drop", direction: 'left'} } ); if (init) { UpdatePos($this.attr('id')); $this.parent().promise().done(function() { console.log($this.dialog('widget').position()); // { top=313, left=641.5} console.log($this.dialog('widget').css('left')); UpdatePos($this.attr('id')); console.log($this.dialog('widget').position()); // { top=121, left=107} console.log($this.dialog('widget').css('left')); }); } The results I'm getting are: box open Object { top=0, left=-78.5} -78.5px Object { top=313, left=641.5} 641.5px Object { top=121, left=107} 107px So looks to me as if the widget is being moved off screen (left=-78.5) and then moved for the animation, and then my code moves it into the location that it should be in (121/107). The position() results for $box.position() or $box.dialog().position() do not change during this debugging section. Maybe this will help someone here - I'm still out of ideas here... ... and I just discovered that when I drag the item around myself, then close and re-open it, it is very unpredictable. Sometimes, it will end up in the correct location horizontally, but not vertically. Sometimes, it will end up back in the center of the screen...

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• Does this language feature already exist?

  - by Pindatjuh

  I'm currently developing a new language for programming in a continuous environment (compare it to electrical engineering), and I've got some ideas on a certain language construction. Let me explain the feature by explanation and then by definition: x = a U b; Where x is a variable and a and b are other variables (or static values). This works like a union between a and b; no duplicates and no specific order. with(x) { // regular 'with' usage; using the global interpretation of "x" x = 5; // will replace the original definition of "x = a U b;" } with(x = a) { // this code block is executed when the "x" variable // has the "a" variable assigned. All references in // this code-block to "x" are references to "a". So saying: x = 5; // would only change the variable "a". If the variable "a" // later on changes, x still equals to 5, in this fashion: // 'x = a U b U 5;' // '[currentscope] = 5;' // thus, 'a = 5;' } with(x = b) { // same but with "b" } with(x != a) { // here the "x" variable refers to any variable // but "a"; thus saying x = 5; // is equal to the rewriting of // 'x = a U b U 5;' // 'b = 5;' (since it was the scope of this block) } with(x = (a U b)) { // guaranteed that "x" is 'a U b'; interacting with "x" // will interact with both "a" and "b". x = 5; // makes both "a" and "b" equal to 5; also the "x" variable // is updated to contain: // 'x = a U b U 5;' // '[currentscope] = 5;' // 'a U b = 5;' // and thus: 'a = 5; b = 5;'. } // etc. In the above, all code-blocks are executed, but the "scope" changes in each block how x is interpreted. In the first block, x is guaranteed to be a: thus interacting with x inside that block will interact on a. The second and the third code-block are only equal in this situation (because not a: then there only remains b). The last block guarantees that x is at least a or b. Further more; U is not the "bitwise or operator", but I've called it the "and/or"-operator. Its definition is: "U" = "and" U "or" (On my blog, http://cplang.wordpress.com/2009/12/19/binop-and-or/, there is more (mathematical) background information on this operator. It's loosely based on sets. Using different syntax, changed it in this question.) Update: more examples. print = "Hello world!" U "How are you?"; // this will print // both values, but the // order doesn't matter. // 'userkey' is a variable containing a key. with(userkey = "a") { print = userkey; // will only print "a". } with(userkey = ("shift" U "a")) { // pressed both "shift" and the "a" key. print = userkey; // will "print" shift and "a", even // if the user also pressed "ctrl": // the interpretation of "userkey" is changed, // such that it only contains the matched cases. } with((userkey = "shift") U (userkey = "a")) { // same as if-statement above this one, showing the distributivity. } x = 5 U 6 U 7; y = x + x; // will be: // y = (5 U 6 U 7) + (5 U 6 U 7) // = 10 U 11 U 12 U 13 U 14 somewantedkey = "ctrl" U "alt" U "space" with(userkey = somewantedkey) { // must match all elements of "somewantedkey" // (distributed the Boolean equals operated) // thus only executed when all the defined keys are pressed } with(somewantedkey = userkey) { // matches only one of the provided "somewantedkey" // thus when only "space" is pressed, this block is executed. } Update2: more examples and some more context. with(x = (a U b)) { // this } // can be written as with((x = a) U (x = b)) { // this: changing the variable like x = 5; // will be rewritten as: // a = 5 and b = 5 } Some background information: I'm building a language which is "time-independent", like Java is "platform-independant". Everything stated in the language is "as is", and is continuously actively executed. This means; the programmer does not know in which order (unless explicitly stated using constructions) elements are, nor when statements are executed. The language is completely separated from the "time"-concept, i.e. it's continuously executed: with(a < 5) { a++; } // this is a loop-structure; // how and when it's executed isn't known however. with(a) { // everytime the "a" variable changes, this code-block is executed. b = 4; with(b < 3) { // runs only three times. } with(b > 0) { b = b - 1; // runs four times } } Update 3: After pondering on the type of this language feature; it closely resemblances Netbeans Platform's Lookup, where each "with"-statement a synchronized agent is, working on it's specific "filter" of objects. Instead of type-based, this is variable-based (fundamentally quite the same; just a different way of identifiying objects). I greatly thank all of you for providing me with very insightful information and links/hints to great topics I can research. Thanks. I do not know if this construction already exists, so that's my question: does this language feature already exist?

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• Objects in Java ArrayList don't get updated.

  - by Sbm007

  This is going to be a very long post, hopefully you can understand what I'm talking about and I appreciate any help. Thanks Basically, I've created a personal, non-commercial project (which I don't plan to release) that can read ZIP and RAR files. It can only read the contents in the archive, the folders inside, the files inside the folders and its properties (such as last modified date, last modified time, CRC checksum, uncompressed size, compressed size and file name). It can't extract files either, so it's really a ZIP/RAR viewer if you may. Anyway that's slightly irrelevant to my problem but I thought I'd give you some background info. Now for my problem: I can successfully list all the folders and files inside a ZIP archive, so now I want to take that raw input and link it together in some useful way. I made 2 classes: ArchiveFile (represents a file inside a ZIP) and ArchiveFolder (represents a folder inside a ZIP). They both have some useful methods such as getLastModifiedDate, getName, getPath and so on. But the difference is that ArchiveFolder can hold an ArrayList of ArchiveFile's and additional ArchiveFolder's (think of this as files and folders inside a folder). Now I want to populate my raw input into one root ArchiveFolder, which will have all the files in the root dir of the ZIP in the ArchiveFile's ArrayList and any additional folders in the root dir of the ZIP in the ArchiveFolder's ArrayList (and this process can continue on like this like a chain reaction (more files/folders in that ArchiveFolder etc etc). So I came up with the following code: while (archive.hasMore()) { String path = ""; ArchiveFolder current = root; String[] contents = archive.getName().split("/"); for (int x = 0; x < contents.length; ++x) { if (x == (contents.length - 1) && !archive.getName().endsWith("/")) { // If on last item and item is a file path += contents[x]; // Update final path ArchiveFile file = new ArchiveFile(path, contents[x], archive.getUncompressedSize(), archive.getCompressedSize(), archive.getModifiedTime(), archive.getModifiedDate(), archive.getCRC()); current.addFile(file); // Create and add the file to the current ArchiveFolder } else if (x == (contents.length - 1)) { // Else if we are on last item and it is a folder path += contents[x] + "/"; // Update final path ArchiveFolder folder = new ArchiveFolder(path, contents[x], archive.getModifiedTime(), archive.getModifiedDate()); current.addFolder(folder); // Create and add this folder to the current ArchiveFile } else { // Else if we are still traversing through the path path += contents[x] + "/"; // Update path ArchiveFolder folder = new ArchiveFolder(path, contents[x]); current.addFolder(folder); // Create and add folder (remember we do not know the modified date/time as all we know is the path, so we can deduce the name only) current = folder; // Update current ArchiveFolder to the newly created one for the next iteration of the for loop } } archive.getNext(); } Assume that root is the root ArchiveFolder (initially empty). And that archive.getName() returns the name of the current file OR folder in the following fashion: file.txt or folder1/file2.txt or folder4/folder2/ (this is a empty folder) etc. So basically the relative path from the root of the ZIP archive. Please read through the comments in the above code to familiarize yourself with it. Also assume that the addFolder method in an ArchiveFile, only adds the folder if it doesn't exist already (so there are no multiple folders) and it also updates the time and date of an existing folder if it is blank (ie it was a intermediate folder we only knew the name of, but now we know its details). The code for addFolder is (pretty self-explanitory): public void addFolder(ArchiveFolder folder) { int loc = folders.indexOf(folder); // folders is the ArrayList containing ArchiveFolder's if (loc == -1) { folders.add(folder); } else { ArchiveFolder real = folders.get(loc); if (real.time == null) { real.setTime(folder.getTime()); real.setDate(folder.getDate()); } } } So I can't see anything wrong with the code, it works and after finishing, the root ArchiveFolder contains all the files in the root of the ZIP as I want it to, and it contains all the direcories in the root folder as I want it to. So you'd think it works as expected, but no the ArchiveFolder's in the root folder don't contain the data inside those 'child' folders, it's just a blank folder with no additional files and folders (while it does really contain some more files/folders when viewed in WinZip). After debugging using Eclipse, the for loop does iterate through all the files (even those not included above), so this led me to believe that there is a problem with this line of the code: current = folder; What it does is, it updates the current folder (used as an intermediate by the loop) to the newly added folder. I thought Java passed by reference and thus all new operations and new additions in future ArchiveFile's and ArchiveFolder's are automatically updated, and parent ArchiveFolder's will be updated accordingly. But that does not appear to be the case? I know this is a long ass post and I really hope anyone can help me out with this. Thanks in advance.

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• Accessing local variable doesn't improve performance

  - by NicMagnier

  The short version Why is this code: var index = (Math.floor(y / scale) * img.width + Math.floor(x / scale)) * 4; More performant than this one? var index = Math.floor(ref_index) * 4; The long version This week, the author of Impact js published an article about some rendering issue: http://www.phoboslab.org/log/2012/09/drawing-pixels-is-hard In the article there was the source of a function to scale an image by accessing pixels in the canvas. I wanted to suggest some traditional ways to optimize this kind of code so that the scaling would be shorter at loading time. But after testing it my result was most of the time worst that the original function. Guessing this was the JavaScript engine that was doing some smart optimization I tried to understand a bit more what was going on so I did a bunch of test. But my results are quite confusing and I would need some help to understand what's going on. I have a test page here: http://www.mx981.com/stuff/resize_bench/test.html jsPerf: http://jsperf.com/local-variable-due-to-the-scope-lookup To start the test, click the picture and the results will appear in the console. There are three different versions: The original code: for( var y = 0; y < heightScaled; y++ ) { for( var x = 0; x < widthScaled; x++ ) { var index = (Math.floor(y / scale) * img.width + Math.floor(x / scale)) * 4; var indexScaled = (y * widthScaled + x) * 4; scaledPixels.data[ indexScaled ] = origPixels.data[ index ]; scaledPixels.data[ indexScaled+1 ] = origPixels.data[ index+1 ]; scaledPixels.data[ indexScaled+2 ] = origPixels.data[ index+2 ]; scaledPixels.data[ indexScaled+3 ] = origPixels.data[ index+3 ]; } } jsPerf: http://jsperf.com/so-accessing-local-variable-doesn-t-improve-performance One of my attempt to optimize it: var ref_index = 0; var ref_indexScaled = 0 var ref_step = 1 / scale; for( var y = 0; y < heightScaled; y++ ) { for( var x = 0; x < widthScaled; x++ ) { var index = Math.floor(ref_index) * 4; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+1 ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+2 ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+3 ]; ref_index+= ref_step; } } jsPerf: http://jsperf.com/so-accessing-local-variable-doesn-t-improve-performance The same optimized code but with recalculating the index variable each time (Hybrid) var ref_index = 0; var ref_indexScaled = 0 var ref_step = 1 / scale; for( var y = 0; y < heightScaled; y++ ) { for( var x = 0; x < widthScaled; x++ ) { var index = (Math.floor(y / scale) * img.width + Math.floor(x / scale)) * 4; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+1 ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+2 ]; scaledPixels.data[ ref_indexScaled++ ] = origPixels.data[ index+3 ]; ref_index+= ref_step; } } jsPerf: http://jsperf.com/so-accessing-local-variable-doesn-t-improve-performance The only difference in the two last one is the calculation of the 'index' variable. And to my surprise the optimized version is slower in most browsers (except opera). Results of personal testing (not the jsPerf tests): Opera Original: 8668ms Optimized: 932ms Hybrid: 8696ms Chrome Original: 139ms Optimized: 145ms Hybrid: 136ms Safari Original: 433ms Optimized: 853ms Hybrid: 451ms Firefox Original: 343ms Optimized: 422ms Hybrid: 350ms After digging around, it seems an usual good practice is to access mainly local variable due to the scope lookup. Because The optimized version only call one local variable it should be faster that the Hybrid code which call multiple variable and object in addition to the various operation involved. So why the "optimized" version is slower? I thought that it might be because some JavaScript engine don't optimize the Optimized version because it is not hot enough but after using --trace-opt in chrome, it seems all version are properly compiled by V8. At this point I am a bit clueless and wonder if somebody would know what is going on? I did also some more test cases in this page: http://www.mx981.com/stuff/resize_bench/index.html

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• 501 Error during Libjingle PCP on Amazone EC2 running Openfire

  - by AeroBuffalo

  I am trying to implement Google's Libjingle (version: 0.6.14) PCP example and I am getting a 501: feature not implemented error during execution. Specifically, the error occurs after each "account" has connected, been authenticated and began communicating with the other. An abbreviated log of the interaction is provided at the end. I have set up my own jabber server (using OpenFire on an Amazon EC2 server), have opened all of the necessary ports and have added each "account" to the other's roster. The server has been set to allow for file transfers. My being new to working with servers, I am not sure why this error is occur and how to go about fixing it. Thanks in advance, AeroBuffalo P.S. Let me know if there is any additional information needed (i.e. the full program log for either/both ends). Receiving End: [018:217] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:17:15 2012 [018:217] <iq to="[email protected]/pcp" type="set" id="5"> [018:217] <jingle xmlns="urn:xmpp:jingle:1" action="session-initiate" sid="402024303" initiator="[email protected]/pcp"> [018:217] <content name="securetunnel" creator="initiator"> [018:217] <description xmlns="http://www.google.com/talk/securetunnel"> [018:217] <type>send:winein.jpeg</type> [018:217] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [018:217] </description> [018:217] <transport xmlns="http://www.google.com/transport/p2p"/> [018:217] </content> [018:217] </jingle> [018:217] <session xmlns="http://www.google.com/session" type="initiate" id="402024303" initiator="[email protected]/pcp"> [018:217] <description xmlns="http://www.google.com/talk/securetunnel"> [018:217] <type>send:winein.jpeg</type> [018:217] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [018:217] </description></session> [018:217] </iq> [018:217] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [018:217] <presence to="[email protected]/pcp" from="forgesend" type="error"> [018:217] <error code="404" type="cancel"> [018:217] <remote-server-not-found xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [018:217] </error></presence> [018:218] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [018:218] <presence to="[email protected]/pcp" from="forgesend" type="error"> [018:218] <error code="404" type="cancel"> [018:218] <remote-server-not-found xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [018:218] </error></presence> [018:264] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [018:264] <iq type="result" id="3" to="[email protected]/pcp"> [018:264] <query xmlns="google:jingleinfo"> [018:264] <stun> [018:264] <server host="stun.xten.net" udp="3478"/> [018:264] <server host="jivesoftware.com" udp="3478"/> [018:264] <server host="igniterealtime.org" udp="3478"/> [018:264] <server host="stun.fwdnet.net" udp="3478"/> [018:264] </stun> [018:264] <publicip ip="65.101.207.121"/> [018:264] </query></iq> [018:420] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [018:420] <iq to="[email protected]/pcp" type="set" id="5" from="[email protected]/pcp"> [018:420] <jingle xmlns="urn:xmpp:jingle:1" action="session-initiate" sid="3548650675" initiator="[email protected]/pcp"> [018:420] <content name="securetunnel" creator="initiator"> [018:420] <description xmlns="http://www.google.com/talk/securetunnel"> [018:420] <type>recv:wineout.jpeg</type> [018:420] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [018:420] </description> [018:420] <transport xmlns="http://www.google.com/transport/p2p"/> [018:420] </content></jingle> [018:420] <session xmlns="http://www.google.com/session" type="initiate" id="3548650675" initiator="[email protected]/pcp"> [018:420] <description xmlns="http://www.google.com/talk/securetunnel"> [018:420] <type>recv:wineout.jpeg</type> [018:420] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [018:420] </description></session></iq> [018:421] TunnelSessionClientBase::OnSessionCreate: received=1 [018:421] Session:3548650675 Old state:STATE_INIT New state:STATE_RECEIVEDINITIATE Type:http://www.google.com/talk/securetunnel Transport:http://www.google.com/transport/p2p [018:421] TunnelSession::OnSessionState(Session::STATE_RECEIVEDINITIATE) [018:421] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:17:15 2012 [018:421] <iq to="[email protected]/pcp" id="5" type="result"/> [018:465] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [018:465] <iq to="[email protected]/pcp" id="5" type="result" from="[email protected]/pcp"/> [198:665] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:20:15 2012 [198:665] <iq type="get" id="162-10" from="forgejabber.com" to="[email protected]/pcp"> [198:665] <ping xmlns="urn:xmpp:ping"/> [198:665] /iq> [198:665] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:20:15 2012 [198:665] <iq type="error" id="162-10" to="forgejabber.com"> [198:665] <ping xmlns="urn:xmpp:ping"/> [198:665] <error code="501" type="cancel"> [198:665] <feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [198:665] </error> [198:665] </iq> Sender: [019:043] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:17:15 2012 [019:043] <iq type="get" id="3"> [019:043] <query xmlns="google:jingleinfo"/> [019:043] </iq> [019:043] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:17:15 2012 [019:043] <iq to="[email protected]/pcp" type="set" id="5"> [019:043] <jingle xmlns="urn:xmpp:jingle:1" action="session-initiate" sid="3548650675" initiator="[email protected]/pcp"> [019:043] <content name="securetunnel" creator="initiator"> [019:043] <description xmlns="http://www.google.com/talk/securetunnel"> [019:043] <type>recv:wineout.jpeg</type> [019:043] <client-cert>--BEGIN CERTIFICATE----END CERTIFICATE--</client-cert> [019:043] </description> [019:043] <transport xmlns="http://www.google.com/transport/p2p"/> [019:043] </content> [019:043] </jingle> [019:043] <session xmlns="http://www.google.com/session" type="initiate" id="3548650675" initiator="[email protected]/pcp"> [019:043] <description xmlns="http://www.google.com/talk/securetunnel"> [019:043] <type>recv:wineout.jpeg</type> [019:043] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [019:043] </description></session></iq> [019:043] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [019:043] <presence to="[email protected]/pcp" from="forgereceive" type="error"> [019:043] <error code="404" type="cancel"> [019:043] <remote-server-not-found xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [019:043] </error></presence> [019:044] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [019:044] <presence to="[email protected]/pcp" from="forgereceive" type="error"> [019:044] <error code="404" type="cancel"> [019:044] <remote-server-not-found xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [019:044] </error></presence> [019:044] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [019:044] <iq to="[email protected]/pcp" type="set" id="5" from="[email protected]/pcp"> [019:044] <jingle xmlns="urn:xmpp:jingle:1" action="session-initiate" sid="402024303" initiator="[email protected]/pcp"> [019:044] <content name="securetunnel" creator="initiator"> [019:044] <description xmlns="http://www.google.com/talk/securetunnel"> [019:044] <type>send:winein.jpeg</type> [019:044] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [019:044] </description> [019:044] <transport xmlns="http://www.google.com/transport/p2p"/> [019:044] </content></jingle> [019:044] <session xmlns="http://www.google.com/session" type="initiate" id="402024303" initiator="[email protected]/pcp"> [019:044] <description xmlns="http://www.google.com/talk/securetunnel"> [019:044] <type>send:winein.jpeg</type> [019:044] <client-cert>--BEGIN CERTIFICATE--END CERTIFICATE--</client-cert> [019:044] </description></session></iq> [019:044] TunnelSessionClientBase::OnSessionCreate: received=1 [019:044] Session:402024303 Old state:STATE_INIT New state:STATE_RECEIVEDINITIATE Type:http://www.google.com/talk/securetunnel Transport:http://www.google.com/transport/p2p [019:044] TunnelSession::OnSessionState(Session::STATE_RECEIVEDINITIATE) [019:044] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:17:15 2012 [019:044] <iq to="[email protected]/pcp" id="5" type="result"/> [019:088] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [019:088] <iq type="result" id="3" to="[email protected]/pcp"> [019:088] <query xmlns="google:jingleinfo"> [019:088] <stun> [019:088] <server host="stun.xten.net" udp="3478"/> [019:088] <server host="jivesoftware.com" udp="3478"/> [019:088] <server host="igniterealtime.org" udp="3478"/> [019:088] <server host="stun.fwdnet.net" udp="3478"/> [019:088] </stun> [019:088] <publicip ip="65.101.207.121"/> [019:088] </query> [019:088] </iq> [019:183] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:17:15 2012 [019:183] <iq to="[email protected]/pcp" id="5" type="result" from="[email protected]/pcp"/> [199:381] RECV <<<<<<<<<<<<<<<<<<<<<<<<< : Thu Jul 5 14:20:15 2012 [199:381] <iq type="get" id="474-11" from="forgejabber.com" to="[email protected]/pcp"> [199:381] <ping xmlns="urn:xmpp:ping"/> [199:381] </iq> [199:381] SEND >>>>>>>>>>>>>>>>>>>>>>>>> : Thu Jul 5 14:20:15 2012 [199:381] <iq type="error" id="474-11" to="forgejabber.com"> [199:381] <ping xmlns="urn:xmpp:ping"/> [199:381] <error code="501" type="cancel"> [199:381] <feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/> [199:382] </error></iq>

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• How to keep multiple connectionString passwords safe, separate, and easy to deploy?

  - by Funka

  I know there are plenty of questions here already about this topic (I've read through as many as I could find), but I haven't yet been able to figure out how best to satisfy my particular criteria. Here are the goals: The ASP.NET application will run on a few different web servers, including localhost workstations for development. This means encrypting web.config using a machine key is out. The application will decide which connection string to use based on the server name (using a switch statement). For example, "localhost" and "dev.example.com" will use the DevDatabaseConnectionString, "test.example.com" will use the TestDatabaseConnectionString, and "www.example.com" will use the ProdDatabaseConnectionString, for example. Ideally, the exact same executables and web.config should be able to run on any of these environments, without needing to tailor or configure each environment separately every time that we deploy (something that seems like it would be easy to forget/mess up one day during a deployment, which is why we moved away from having just one connectionstring that has to be changed on each target). Deployment is currently accomplished via FTP. We will not have command-line access to the production web server. This means using aspnet_regiis.exe is out. (I could run on localhost, however, if this would still work.) We would prefer to not have to recompile the application whenever a password changes, so using web.config (or db.config or whatever) seems to make the most sense. A developer should not be able to decrypt the production database password. If a developer checks the source code out onto their localhost laptop (which would determine that it should be using the DevDatabaseConnectionString, remember?) and the laptop gets lost or stolen, it should not be possible to get at the other connection strings. Thus, having a single RSA private key to un-encrypt all three passwords cannot be considered. (Contrary to #3 above, it does seem like we'd need to have three separate key files if we went this route; these could be installed once per machine, and should the wrong key file get deployed to the wrong server, the worst that should happen is that the app can't decrypt anything---and not allow the wrong host to access the wrong database!) I know this is probably a subjective question (asking for a "best" way to do something), but given the criteria I've mentioned, I'm hoping that a single best answer will indeed arise. Thank you!

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• How to get compatibility between C# and SQL2k8 AES Encryption?

  - by Victor Rodrigues

  I have an AES encryption being made on two columns: one of these columns is stored at a SQL Server 2000 database; the other is stored at a SQL Server 2008 database. As the first column's database (2000) doesn't have native functionality for encryption / decryption, we've decided to do the cryptography logic at application level, with .NET classes, for both. But as the second column's database (2008) allow this kind of functionality, we'd like to make the data migration using the database functions to be faster, since the data migration in SQL 2k is much smaller than this second and it will last more than 50 hours because of being made at application level. My problem started at this point: using the same key, I didn't achieve the same result when encrypting a value, neither the same result size. Below we have the full logic in both sides.. Of course I'm not showing the key, but everything else is the same: private byte[] RijndaelEncrypt(byte[] clearData, byte[] Key) { var memoryStream = new MemoryStream(); Rijndael algorithm = Rijndael.Create(); algorithm.Key = Key; algorithm.IV = InitializationVector; var criptoStream = new CryptoStream(memoryStream, algorithm.CreateEncryptor(), CryptoStreamMode.Write); criptoStream.Write(clearData, 0, clearData.Length); criptoStream.Close(); byte[] encryptedData = memoryStream.ToArray(); return encryptedData; } private byte[] RijndaelDecrypt(byte[] cipherData, byte[] Key) { var memoryStream = new MemoryStream(); Rijndael algorithm = Rijndael.Create(); algorithm.Key = Key; algorithm.IV = InitializationVector; var criptoStream = new CryptoStream(memoryStream, algorithm.CreateDecryptor(), CryptoStreamMode.Write); criptoStream.Write(cipherData, 0, cipherData.Length); criptoStream.Close(); byte[] decryptedData = memoryStream.ToArray(); return decryptedData; } This is the SQL Code sample: open symmetric key columnKey decryption by password = N'{pwd!!i_ll_not_show_it_here}' declare @enc varchar(max) set @enc = dbo.VarBinarytoBase64(EncryptByKey(Key_GUID('columnKey'), 'blablabla')) select LEN(@enc), @enc This varbinaryToBase64 is a tested sql function we use to convert varbinary to the same format we use to store strings in the .net application. The result in C# is: eg0wgTeR3noWYgvdmpzTKijkdtTsdvnvKzh+uhyN3Lo= The same result in SQL2k8 is: AI0zI7D77EmqgTQrdgMBHAEAAACyACXb+P3HvctA0yBduAuwPS4Ah3AB4Dbdj2KBGC1Dk4b8GEbtXs5fINzvusp8FRBknF15Br2xI1CqP0Qb/M4w I just didn't get yet what I'm doing wrong. Do you have any ideas? EDIT: One point I think is crucial: I have one Initialization Vector at my C# code, 16 bytes. This IV is not set at SQL symmetric key, could I do this? But even not filling the IV in C#, I get very different results, both in content and length.

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• Settings designer file complains when protecting configuration for connectionStrings in App.Config i

  - by Joe

  Hi, I am trying to encrypt Configuration Information Using Protected Configuration in Visual Studio 2010. I have the following info speicifed in the App.Config file: <connectionStrings configProtectionProvider="TheProviderName"> <EncryptedData> <CipherData> <CipherValue>VALUE GOES HERE</CipherValue> </CipherData> </EncryptedData> </connectionStrings> <appSettings configProtectionProvider="TheProviderName"> <EncryptedData> <CipherData> <CipherValue>VALUE GOES HERE</CipherValue> </CipherData> </EncryptedData> </appSettings> However, when I then go to the Settings area of the Projects Properties to view the settings in the Designer, I get prompted with the following error "An error occured while reading the App.config file. The file might be corrupted or contain invalid XML." I understand that my changes are causing the error, however, is there anyway I can bypass that the information is not read into at design view? (Of course the best way would be to make the tags be recognized by the designer, is there any way to do this?) I tried adding <connectionStrings configProtectionProvider="TheProviderName" xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0"> to connectionStrings as well as to the appSettings, but with no luck, the intellisense is bypassed in the config file, but the designer still complains. I would be satisfied if the designer would not complain about this "error", which is not actually an error because Microsoft states here that it should work. ASP.NET 2.0 provides a new feature, called protected configuration, that enables you to encrypt sensitive information in a configuration file. Although primarily designed for ASP.NET, protected configuration can also be used to encrypt configuration file sections in Windows applications. For a detailed description of the new protected configuration capabilities, see Encrypting Configuration Information Using Protected Configuration. And yes, it does work to encrypt it and to decrypt it and use it, it is just very annoying and frustrating that the designer complains about it. Anyone who knows which xsd file that is used (if used) to verify the contents of the App.config file in the design view? Any help appreciated.

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• Webservice for uploading data: security considerations

  - by Philip Daubmeier

  Hi everyone! Im not sure about what authentification method I should use for my webservice. I've searched on SO, and found nothing that helped me. Preliminary Im building an application that uploads data from a local database to a server (running my webservice), where all records are merged and stored in a central database. I am currently binary serializing a DataTable, that holds a small fragment of the local database, where all uninteresting stuff is already filtered out. The byte[] (serialized DataTable), together with the userid and a hash of the users password is then uploaded to the webservice via SOAP. The application together with the webservice already work exactly like intended. The Problem The issue I am thinking about is now: What is if someone just sniffs the network traffic, 'steals' the users id and password hash to send his own SOAP message with modified data that corrupts my database? Options The approaches to solving that problem, I already thought of, are: Using ssl + certificates for establishing the connection: I dont really want to use ssl, I would prefer a simpler solution. After all, every information that is transfered to the webservice can be seen on the website later on. What I want to say is: there is no secret/financial/business-critical information, that has to be hidden. I think ssl would be sort of an overkill for that task. Encrypting the byte[]: I think that would be a performance killer, considering that the goal of the excercise was simply to authenticate the user. Hashing the users password together with the data: I kind of like the idea: Creating a checksum from the data, concatenating that checksum with the password-hash and hashing this whole thing again. That would assure the data was sent from this specific user, and the data wasnt modified. The actual question So, what do you think is the best approach in terms of meeting the following requirements? Rather simple solution (As it doesnt have to be super secure; no secret/business-critical information transfered) Easily implementable retrospectively (Dont want to write it all again :) ) Doesnt impact to much on performance What do you think of my prefered solution, the last one in the list above? Is there any alternative solution I didnt mention, that would fit better? You dont have to answer every question in detail. Just push me in the right direction. I very much appreciate every well-grounded opinion. Thanks in advance!

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• NoSQL with RavenDB and ASP.NET MVC - Part 1

  - by shiju

   A while back, I have blogged NoSQL with MongoDB, NoRM and ASP.NET MVC Part 1 and Part 2 on how to use MongoDB with an ASP.NET MVC application. The NoSQL movement is getting big attention and RavenDB is the latest addition to the NoSQL and document database world. RavenDB is an Open Source (with a commercial option) document database for the .NET/Windows platform developed  by Ayende Rahien.  Raven stores schema-less JSON documents, allow you to define indexes using Linq queries and focus on low latency and high performance. RavenDB is .NET focused document database which comes with a fully functional .NET client API  and supports LINQ. RavenDB comes with two components, a server and a client API. RavenDB is a REST based system, so you can write your own HTTP cleint API. As a .NET developer, RavenDB is becoming my favorite document database. Unlike other document databases, RavenDB is supports transactions using System.Transactions. Also it's supports both embedded and server mode of database. You can access RavenDB site at http://ravendb.netA demo App with ASP.NET MVCLet's create a simple demo app with RavenDB and ASP.NET MVC. To work with RavenDB, do the following steps. Go to http://ravendb.net/download and download the latest build.Unzip the downloaded file.Go to the /Server directory and run the RavenDB.exe. This will start the RavenDB server listening on localhost:8080You can change the port of RavenDB  by modifying the "Raven/Port" appSetting value in the RavenDB.exe.config file.When running the RavenDB, it will automatically create a database in the /Data directory. You can change the directory name data by modifying "Raven/DataDirt" appSetting value in the RavenDB.exe.config file.RavenDB provides a browser based admin tool. When the Raven server is running, You can be access the browser based admin tool and view and edit documents and index using your browser admin tool. The web admin tool available at http://localhost:8080The below is the some screen shots of web admin tool     Working with ASP.NET MVC  To working with RavenDB in our demo ASP.NET MVC application, do the following steps Step 1 - Add reference to Raven Cleint API In our ASP.NET MVC application, Add a reference to the Raven.Client.Lightweight.dll from the Client directory. Step 2 - Create DocumentStoreThe document store would be created once per application. Let's create a DocumentStore on application start-up in the Global.asax.cs. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); The above code will create a Raven DB document store and will be listening the server locahost at port 8080    Step 3 - Create DocumentSession on BeginRequest   Let's create a DocumentSession on BeginRequest event in the Global.asax.cs. We are using the document session for every unit of work. In our demo app, every HTTP request would be a single Unit of Work (UoW). BeginRequest += (sender, args) =>   HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); Step 4 - Destroy the DocumentSession on EndRequest  EndRequest += (o, eventArgs) => {     var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable;     if (disposable != null)         disposable.Dispose(); };  At the end of HTTP request, we are destroying the DocumentSession  object.The below  code block shown all the code in the Global.asax.cs  private const string RavenSessionKey = "RavenMVC.Session"; private static DocumentStore documentStore;   protected void Application_Start() { //Create a DocumentStore in Application_Start //DocumentStore should be created once per application and stored as a singleton. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); AreaRegistration.RegisterAllAreas(); RegisterRoutes(RouteTable.Routes); //DI using Unity 2.0 ConfigureUnity(); }   public MvcApplication() { //Create a DocumentSession on BeginRequest   //create a document session for every unit of work BeginRequest += (sender, args) =>     HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); //Destroy the DocumentSession on EndRequest EndRequest += (o, eventArgs) => { var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable; if (disposable != null) disposable.Dispose(); }; }   //Getting the current DocumentSession public static IDocumentSession CurrentSession {   get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } }  We have setup all necessary code in the Global.asax.cs for working with RavenDB. For our demo app, Let’s write a domain class  public class Category {       public string Id { get; set; }       [Required(ErrorMessage = "Name Required")]     [StringLength(25, ErrorMessage = "Must be less than 25 characters")]     public string Name { get; set;}     public string Description { get; set; }   } We have created simple domain entity Category. Let's create repository class for performing CRUD operations against our domain entity Category.  public interface ICategoryRepository {     Category Load(string id);     IEnumerable<Category> GetCategories();     void Save(Category category);     void Delete(string id);       }    public class CategoryRepository : ICategoryRepository {     private IDocumentSession session;     public CategoryRepository()     {             session = MvcApplication.CurrentSession;     }     //Load category based on Id     public Category Load(string id)     {         return session.Load<Category>(id);     }     //Get all categories     public IEnumerable<Category> GetCategories()     {         var categories= session.LuceneQuery<Category>()                 .WaitForNonStaleResults()             .ToArray();         return categories;       }     //Insert/Update category     public void Save(Category category)     {         if (string.IsNullOrEmpty(category.Id))         {             //insert new record             session.Store(category);         }         else         {             //edit record             var categoryToEdit = Load(category.Id);             categoryToEdit.Name = category.Name;             categoryToEdit.Description = category.Description;         }         //save the document session         session.SaveChanges();     }     //delete a category     public void Delete(string id)     {         var category = Load(id);         session.Delete<Category>(category);         session.SaveChanges();     }        } For every CRUD operations, we are taking the current document session object from HttpContext object. session = MvcApplication.CurrentSession; We are calling the static method CurrentSession from the Global.asax.cs public static IDocumentSession CurrentSession {     get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } }  Retrieve Entities  The Load method get the single Category object based on the Id. RavenDB is working based on the REST principles and the Id would be like categories/1. The Id would be created by automatically when a new object is inserted to the document store. The REST uri categories/1 represents a single category object with Id representation of 1.   public Category Load(string id) {    return session.Load<Category>(id); } The GetCategories method returns all the categories calling the session.LuceneQuery method. RavenDB is using a lucen query syntax for querying. I will explain more details about querying and indexing in my future posts.   public IEnumerable<Category> GetCategories() {     var categories= session.LuceneQuery<Category>()             .WaitForNonStaleResults()         .ToArray();     return categories;   } Insert/Update entityFor insert/Update a Category entity, we have created Save method in repository class. If  the Id property of Category is null, we call Store method of Documentsession for insert a new record. For editing a existing record, we load the Category object and assign the values to the loaded Category object. The session.SaveChanges() will save the changes to document store.  //Insert/Update category public void Save(Category category) {     if (string.IsNullOrEmpty(category.Id))     {         //insert new record         session.Store(category);     }     else     {         //edit record         var categoryToEdit = Load(category.Id);         categoryToEdit.Name = category.Name;         categoryToEdit.Description = category.Description;     }     //save the document session     session.SaveChanges(); }  Delete Entity  In the Delete method, we call the document session's delete method and call the SaveChanges method to reflect changes in the document store.  public void Delete(string id) {     var category = Load(id);     session.Delete<Category>(category);     session.SaveChanges(); }  Let’s create ASP.NET MVC controller and controller actions for handling CRUD operations for the domain class Category  public class CategoryController : Controller { private ICategoryRepository categoyRepository; //DI enabled constructor public CategoryController(ICategoryRepository categoyRepository) {     this.categoyRepository = categoyRepository; } public ActionResult Index() {         var categories = categoyRepository.GetCategories();     if (categories == null)         return RedirectToAction("Create");     return View(categories); }   [HttpGet] public ActionResult Edit(string id) {     var category = categoyRepository.Load(id);         return View("Save",category); } // GET: /Category/Create [HttpGet] public ActionResult Create() {     var category = new Category();     return View("Save", category); } [HttpPost] public ActionResult Save(Category category) {     if (!ModelState.IsValid)     {         return View("Save", category);     }           categoyRepository.Save(category);         return RedirectToAction("Index");     }        [HttpPost] public ActionResult Delete(string id) {     categoyRepository.Delete(id);     var categories = categoyRepository.GetCategories();     return PartialView("CategoryList", categories);      }        }  RavenDB is an awesome document database and I hope that it will be the winner in .NET space of document database world.  The source code of demo application available at http://ravenmvc.codeplex.com/

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• SharpDX: best practice for multiple RenderForms?

  - by Rob Jellinghaus

  I have an XNA app, but I really need to add multiple render windows, which XNA doesn't do. I'm looking at SharpDX (both for multi-window support and for DX11 / Metro / many other reasons). I decided to hack up the SharpDX DX11 MultiCubeTexture sample to see if I could make it work. My changes are pretty trivial. The original sample had: [STAThread] private static void Main() { var form = new RenderForm("SharpDX - MiniCubeTexture Direct3D11 Sample"); ... I changed this to: struct RenderFormWithActions { internal readonly RenderForm Form; // should just be Action but it's not in System namespace?! internal readonly Action RenderAction; internal readonly Action DisposeAction; internal RenderFormWithActions(RenderForm form, Action renderAction, Action disposeAction) { Form = form; RenderAction = renderAction; DisposeAction = disposeAction; } } [STAThread] private static void Main() { // hackity hack new Thread(new ThreadStart(() = { RenderFormWithActions form1 = CreateRenderForm(); RenderLoop.Run(form1.Form, () = form1.RenderAction(0)); form1.DisposeAction(0); })).Start(); new Thread(new ThreadStart(() = { RenderFormWithActions form2 = CreateRenderForm(); RenderLoop.Run(form2.Form, () = form2.RenderAction(0)); form2.DisposeAction(0); })).Start(); } private static RenderFormWithActions CreateRenderForm() { var form = new RenderForm("SharpDX - MiniCubeTexture Direct3D11 Sample"); ... Basically, I split out all the Main() code into a separate method which creates a RenderForm and two delegates (a render delegate, and a dispose delegate), and bundles them all together into a struct. I call this method twice, each time from a separate, new thread. Then I just have one RenderLoop on each new thread. I was thinking this wouldn't work because of the [STAThread] declaration -- I thought I would need to create the RenderForm on the main (STA) thread, and run only a single RenderLoop on that thread. Fortunately, it seems I was wrong. This works quite well -- if you drag one of the forms around, it stops rendering while being dragged, but starts again when you drop it; and the other form keeps chugging away. My questions are pretty basic: Is this a reasonable approach, or is there some lurking threading issue that might make trouble? My code simply duplicates all the setup code -- it makes a duplicate SwapChain, Device, Texture2D, vertex buffer, everything. I don't have a problem with this level of duplication -- my app is not intensive enough to suffer resource issues -- but nonetheless, is there a better practice? Is there any good reference for which DirectX structures can safely be shared, and which can't? It appears that RenderLoop.Run calls the render delegate in a tight loop. Is there any standard way to limit the frame rate of RenderLoop.Run, if you don't want a 400FPS app eating 100% of your CPU? Should I just Thread.Sleep(30) in the render delegate? (I asked on the sharpdx.org forums as well, but Alexandre is on vacation for two weeks, and my sister wants me to do a performance with my app at her wedding in three and a half weeks, so I'm mighty incented here! http://robjsoftware.org for details of what I'm building....)

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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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• Metro: Declarative Data Binding

  - by Stephen.Walther

  The goal of this blog post is to describe how declarative data binding works in the WinJS library. In particular, you learn how to use both the data-win-bind and data-win-bindsource attributes. You also learn how to use calculated properties and converters to format the value of a property automatically when performing data binding. By taking advantage of WinJS data binding, you can use the Model-View-ViewModel (MVVM) pattern when building Metro style applications with JavaScript. By using the MVVM pattern, you can prevent your JavaScript code from spinning into chaos. The MVVM pattern provides you with a standard pattern for organizing your JavaScript code which results in a more maintainable application. Using Declarative Bindings You can use the data-win-bind attribute with any HTML element in a page. The data-win-bind attribute enables you to bind (associate) an attribute of an HTML element to the value of a property. Imagine, for example, that you want to create a product details page. You want to show a product object in a page. In that case, you can create the following HTML page to display the product details: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Product Details</h1> <div class="field"> Product Name: <span data-win-bind="innerText:name"></span> </div> <div class="field"> Product Price: <span data-win-bind="innerText:price"></span> </div> <div class="field"> Product Picture: <br /> <img data-win-bind="src:photo;alt:name" /> </div> </body> </html> The HTML page above contains three data-win-bind attributes – one attribute for each product property displayed. You use the data-win-bind attribute to set properties of the HTML element associated with the data-win-attribute. The data-win-bind attribute takes a semicolon delimited list of element property names and data source property names: data-win-bind=”elementPropertyName:datasourcePropertyName; elementPropertyName:datasourcePropertyName;…” In the HTML page above, the first two data-win-bind attributes are used to set the values of the innerText property of the SPAN elements. The last data-win-bind attribute is used to set the values of the IMG element’s src and alt attributes. By the way, using data-win-bind attributes is perfectly valid HTML5. The HTML5 standard enables you to add custom attributes to an HTML document just as long as the custom attributes start with the prefix data-. So you can add custom attributes to an HTML5 document with names like data-stephen, data-funky, or data-rover-dog-is-hungry and your document will validate. The product object displayed in the page above with the data-win-bind attributes is created in the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var product = { name: "Tesla", price: 80000, photo: "/images/TeslaPhoto.png" }; WinJS.Binding.processAll(null, product); } }; app.start(); })(); In the code above, a product object is created with a name, price, and photo property. The WinJS.Binding.processAll() method is called to perform the actual binding (Don’t confuse WinJS.Binding.processAll() and WinJS.UI.processAll() – these are different methods). The first parameter passed to the processAll() method represents the root element for the binding. In other words, binding happens on this element and its child elements. If you provide the value null, then binding happens on the entire body of the document (document.body). The second parameter represents the data context. This is the object that has the properties which are displayed with the data-win-bind attributes. In the code above, the product object is passed as the data context parameter. Another word for data context is view model.  Creating Complex View Models In the previous section, we used the data-win-bind attribute to display the properties of a simple object: a single product. However, you can use binding with more complex view models including view models which represent multiple objects. For example, the view model in the following default.js file represents both a customer and a product object. Furthermore, the customer object has a nested address object: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var viewModel = { customer: { firstName: "Fred", lastName: "Flintstone", address: { street: "1 Rocky Way", city: "Bedrock", country: "USA" } }, product: { name: "Bowling Ball", price: 34.55 } }; WinJS.Binding.processAll(null, viewModel); } }; app.start(); })(); The following page displays the customer (including the customer address) and the product. Notice that you can use dot notation to refer to child objects in a view model such as customer.address.street. <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Customer Details</h1> <div class="field"> First Name: <span data-win-bind="innerText:customer.firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:customer.lastName"></span> </div> <div class="field"> Address: <address> <span data-win-bind="innerText:customer.address.street"></span> <br /> <span data-win-bind="innerText:customer.address.city"></span> <br /> <span data-win-bind="innerText:customer.address.country"></span> </address> </div> <h1>Product</h1> <div class="field"> Name: <span data-win-bind="innerText:product.name"></span> </div> <div class="field"> Price: <span data-win-bind="innerText:product.price"></span> </div> </body> </html> A view model can be as complicated as you need and you can bind the view model to a view (an HTML document) by using declarative bindings. Creating Calculated Properties You might want to modify a property before displaying the property. For example, you might want to format the product price property before displaying the property. You don’t want to display the raw product price “80000”. Instead, you want to display the formatted price “$80,000”. You also might need to combine multiple properties. For example, you might need to display the customer full name by combining the values of the customer first and last name properties. In these situations, it is tempting to call a function when performing binding. For example, you could create a function named fullName() which concatenates the customer first and last name. Unfortunately, the WinJS library does not support the following syntax: <span data-win-bind=”innerText:fullName()”></span> Instead, in these situations, you should create a new property in your view model that has a getter. For example, the customer object in the following default.js file includes a property named fullName which combines the values of the firstName and lastName properties: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var customer = { firstName: "Fred", lastName: "Flintstone", get fullName() { return this.firstName + " " + this.lastName; } }; WinJS.Binding.processAll(null, customer); } }; app.start(); })(); The customer object has a firstName, lastName, and fullName property. Notice that the fullName property is defined with a getter function. When you read the fullName property, the values of the firstName and lastName properties are concatenated and returned. The following HTML page displays the fullName property in an H1 element. You can use the fullName property in a data-win-bind attribute in exactly the same way as any other property. <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1 data-win-bind="innerText:fullName"></h1> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> </body> </html> Creating a Converter In the previous section, you learned how to format the value of a property by creating a property with a getter. This approach makes sense when the formatting logic is specific to a particular view model. If, on the other hand, you need to perform the same type of formatting for multiple view models then it makes more sense to create a converter function. A converter function is a function which you can apply whenever you are using the data-win-bind attribute. Imagine, for example, that you want to create a general function for displaying dates. You always want to display dates using a short format such as 12/25/1988. The following JavaScript file – named converters.js – contains a shortDate() converter: (function (WinJS) { var shortDate = WinJS.Binding.converter(function (date) { return date.getMonth() + 1 + "/" + date.getDate() + "/" + date.getFullYear(); }); // Export shortDate WinJS.Namespace.define("MyApp.Converters", { shortDate: shortDate }); })(WinJS); The file above uses the Module Pattern, a pattern which is used through the WinJS library. To learn more about the Module Pattern, see my blog entry on namespaces and modules: http://stephenwalther.com/blog/archive/2012/02/22/windows-web-applications-namespaces-and-modules.aspx The file contains the definition for a converter function named shortDate(). This function converts a JavaScript date object into a short date string such as 12/1/1988. The converter function is created with the help of the WinJS.Binding.converter() method. This method takes a normal function and converts it into a converter function. Finally, the shortDate() converter is added to the MyApp.Converters namespace. You can call the shortDate() function by calling MyApp.Converters.shortDate(). The default.js file contains the customer object that we want to bind. Notice that the customer object has a firstName, lastName, and birthday property. We will use our new shortDate() converter when displaying the customer birthday property: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var customer = { firstName: "Fred", lastName: "Flintstone", birthday: new Date("12/1/1988") }; WinJS.Binding.processAll(null, customer); } }; app.start(); })(); We actually use our shortDate converter in the HTML document. The following HTML document displays all of the customer properties: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/converters.js"></script> </head> <body> <h1>Customer Details</h1> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> <div class="field"> Birthday: <span data-win-bind="innerText:birthday MyApp.Converters.shortDate"></span> </div> </body> </html> Notice the data-win-bind attribute used to display the birthday property. It looks like this: <span data-win-bind="innerText:birthday MyApp.Converters.shortDate"></span> The shortDate converter is applied to the birthday property when the birthday property is bound to the SPAN element’s innerText property. Using data-win-bindsource Normally, you pass the view model (the data context) which you want to use with the data-win-bind attributes in a page by passing the view model to the WinJS.Binding.processAll() method like this: WinJS.Binding.processAll(null, viewModel); As an alternative, you can specify the view model declaratively in your markup by using the data-win-datasource attribute. For example, the following default.js script exposes a view model with the fully-qualified name of MyWinWebApp.viewModel: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { // Create view model var viewModel = { customer: { firstName: "Fred", lastName: "Flintstone" }, product: { name: "Bowling Ball", price: 12.99 } }; // Export view model to be seen by universe WinJS.Namespace.define("MyWinWebApp", { viewModel: viewModel }); // Process data-win-bind attributes WinJS.Binding.processAll(); } }; app.start(); })(); In the code above, a view model which represents a customer and a product is exposed as MyWinWebApp.viewModel. The following HTML page illustrates how you can use the data-win-bindsource attribute to bind to this view model: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Customer Details</h1> <div data-win-bindsource="MyWinWebApp.viewModel.customer"> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> </div> <h1>Product</h1> <div data-win-bindsource="MyWinWebApp.viewModel.product"> <div class="field"> Name: <span data-win-bind="innerText:name"></span> </div> <div class="field"> Price: <span data-win-bind="innerText:price"></span> </div> </div> </body> </html> The data-win-bindsource attribute is used twice in the page above: it is used with the DIV element which contains the customer details and it is used with the DIV element which contains the product details. If an element has a data-win-bindsource attribute then all of the child elements of that element are affected. The data-win-bind attributes of all of the child elements are bound to the data source represented by the data-win-bindsource attribute. Summary The focus of this blog entry was data binding using the WinJS library. You learned how to use the data-win-bind attribute to bind the properties of an HTML element to a view model. We also discussed several advanced features of data binding. We examined how to create calculated properties by including a property with a getter in your view model. We also discussed how you can create a converter function to format the value of a view model property when binding the property. Finally, you learned how to use the data-win-bindsource attribute to specify a view model declaratively.

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• CascadingDropDown jQuery Plugin for ASP.NET MVC

  - by rajbk

  CascadingDropDown is a jQuery plugin that can be used by a select list to get automatic population using AJAX. A sample ASP.NET MVC project is attached at the bottom of this post.   Usage The code below shows two select lists : <select id="customerID" name="customerID"> <option value="ALFKI">Maria Anders</option> <option value="ANATR">Ana Trujillo</option> <option value="ANTON">Antonio Moreno</option> </select>   <select id="orderID" name="orderID"> </select> When a customer is selected in the first select list, the second list will auto populate itself with the following code: $("#orderID").CascadingDropDown("#customerID", '/Sales/AsyncOrders'); Internally, an AJAX post is made to ‘/Sales/AsyncOrders’ with the post body containing  customerID=[selectedCustomerID]. This executes the action AsyncOrders on the SalesController with signature AsyncOrders(string customerID).  The AsyncOrders method returns JSON which is then used to populate the select list. The JSON format expected is shown below : [{ "Text": "John", "Value": "10326" }, { "Text": "Jane", "Value": "10801" }] Details $(targetID).CascadingDropDown(sourceID, url, settings) targetID The ID of the select list that will auto populate.  sourceID The ID of the select list, which, on change, causes the targetID to auto populate. url The url to post to Options promptText Text for the first item in the select list Default : -- Select -- loadingText Optional text to display in the select list while it is being loaded. Default : Loading.. errorText Optional text to display if an error occurs while populating the list Default: Error loading data. postData Data you want posted to the url in place of the default Example : { postData : { customerID : $(‘#custID’), orderID : $(‘#orderID’) }} will cause customerID=ALFKI&orderID=2343 to be sent as the POST body. Default: A text string obtained by calling serialize on the sourceID onLoading (event) Raised before the list is populated. onLoaded (event) Raised after the list is populated, The code below shows how to “animate” the  select list after load. Example using custom options: $("#orderID").CascadingDropDown("#customerID", '/Sales/AsyncOrders', { promptText: '-- Pick an Order--', onLoading: function () { $(this).css("background-color", "#ff3"); }, onLoaded: function () { $(this).animate({ backgroundColor: '#ffffff' }, 300); } }); To return JSON from our action method, we use the Json ActionResult passing in an IEnumerable<SelectListItem>. public ActionResult AsyncOrders(string customerID) { var orders = repository.GetOrders(customerID).ToList().Select(a => new SelectListItem() { Text = a.OrderDate.HasValue ? a.OrderDate.Value.ToString("MM/dd/yyyy") : "[ No Date ]", Value = a.OrderID.ToString(), }); return Json(orders); } Sample Project using VS 2010 RTM NorthwindCascading.zip

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• Handling WCF Service Paths in Silverlight 4 – Relative Path Support

  - by dwahlin

  If you’re building Silverlight applications that consume data then you’re probably making calls to Web Services. We’ve been successfully using WCF along with Silverlight for several client Line of Business (LOB) applications and passing a lot of data back and forth. Due to the pain involved with updating the ServiceReferences.ClientConfig file generated by a Silverlight service proxy (see Tim Heuer’s post on that subject to see different ways to deal with it) we’ve been using our own technique to figure out the service URL. Going that route makes it a peace of cake to switch between development, staging and production environments. To start, we have a ServiceProxyBase class that handles identifying the URL to use based on the XAP file’s location (this assumes that the service is in the same Web project that serves up the XAP file). The GetServiceUrlBase() method handles this work: public class ServiceProxyBase { public ServiceProxyBase() { if (!IsDesignTime) { ServiceUrlBase = GetServiceUrlBase(); } } public string ServiceUrlBase { get; set; } public static bool IsDesignTime { get { return (Application.Current == null) || (Application.Current.GetType() == typeof (Application)); } } public static string GetServiceUrlBase() { if (!IsDesignTime) { string url = Application.Current.Host.Source.OriginalString; return url.Substring(0, url.IndexOf("/ClientBin", StringComparison.InvariantCultureIgnoreCase)); } return null; } } Silverlight 4 now supports relative paths to services which greatly simplifies things.  We changed the code above to the following: public class ServiceProxyBase { private const string ServiceUrlPath = "../Services/JobPlanService.svc"; public ServiceProxyBase() { if (!IsDesignTime) { ServiceUrl = ServiceUrlPath; } } public string ServiceUrl { get; set; } public static bool IsDesignTime { get { return (Application.Current == null) || (Application.Current.GetType() == typeof (Application)); } } public static string GetServiceUrl() { if (!IsDesignTime) { return ServiceUrlPath; } return null; } } Our ServiceProxy class derives from ServiceProxyBase and handles creating the ABC’s (Address, Binding, Contract) needed for a WCF service call. Looking through the code (mainly the constructor) you’ll notice that the service URI is created by supplying the base path to the XAP file along with the relative path defined in ServiceProxyBase:   public class ServiceProxy : ServiceProxyBase, IServiceProxy { private const string CompletedEventargs = "CompletedEventArgs"; private const string Completed = "Completed"; private const string Async = "Async"; private readonly CustomBinding _Binding; private readonly EndpointAddress _EndPointAddress; private readonly Uri _ServiceUri; private readonly Type _ProxyType = typeof(JobPlanServiceClient); public ServiceProxy() { _ServiceUri = new Uri(Application.Current.Host.Source, ServiceUrl); var elements = new BindingElementCollection { new BinaryMessageEncodingBindingElement(), new HttpTransportBindingElement { MaxBufferSize = 2147483647, MaxReceivedMessageSize = 2147483647 } }; // order of entries in collection is significant: dumb _Binding = new CustomBinding(elements); _EndPointAddress = new EndpointAddress(_ServiceUri); } #region IServiceProxy Members /// <summary> /// Used to call a WCF service operation. /// </summary> /// <typeparam name="T">The type of EventArgs that will be returned by the service operation.</typeparam> /// <param name="callback">The method to call once the WCF call returns (the callback).</param> /// <param name="parameters">Any parameters that the service operation expects.</param> public void CallService<T>(EventHandler<T> callback, params object[] parameters) where T : EventArgs { try { var proxy = new JobPlanServiceClient(_Binding, _EndPointAddress); string action = typeof (T).Name.Replace(CompletedEventargs, String.Empty); _ProxyType.GetEvent(action + Completed).AddEventHandler(proxy, callback); _ProxyType.InvokeMember(action + Async, BindingFlags.InvokeMethod, null, proxy, parameters); } catch (Exception exp) { MessageBox.Show("Unable to use ServiceProxy.CallService to retrieve data: " + exp.Message); } } #endregion } The relative path support for calling services in Silverlight 4 definitely simplifies code and is yet another good reason to move from Silverlight 3 to Silverlight 4.   For more information about onsite, online and video training, mentoring and consulting solutions for .NET, SharePoint or Silverlight please visit http://www.thewahlingroup.com.

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• Windows CE: Using IOCTL_DISK_GET_STORAGEID

  - by Bruce Eitman

  A customer approached me recently to ask if I had any code that demonstrated how to use STORAGE_IDENTIFICATION, which is the data structure used to get the Storage ID from a disk. I didn’t have anything, which of course sends me off writing code and blogging about it. Simple enough, right? Go read the documentation for STORAGE_IDENTIFICATION which lead me to IOCTL_DISK_GET_STORAGEID. Except that the documentation for IOCTL_DISK_GET_STORAGEID seems to have a problem.   The most obvious problem is that it shows how to call CreateFile() to get the handle to use with DeviceIoControl(), but doesn’t show how to call DeviceIoControl(). That is odd, but not really a problem. But, the call to CreateFile() seems to be wrong, or at least it was in my testing. The documentation shows the call to be: hVolume = CreateFile(TEXT("\Storage Card\Vol:"), GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); I tried that, but my testing with an SD card mounted as Storage Card failed on the call to CreateFile(). I tried several variations of this, but none worked. Then I remembered that some time ago I wrote an article about enumerating the disks (Windows CE: Displaying Disk Information). I pulled up that code and tried again with both the disk device name and the partition volume name. The disk device name worked. The device names are DSKx:, where x is the disk number. I created the following function to output the Manufacturer ID and Serial Number returned from IOCTL_DISK_GET_STORAGEID:   #include "windows.h" #include "Diskio.h"     BOOL DisplayDiskID( TCHAR *Disk ) {                 STORAGE_IDENTIFICATION *StoreID = NULL;                 STORAGE_IDENTIFICATION GetSizeStoreID;                 DWORD dwSize;                 HANDLE hVol;                 TCHAR VolumeName[MAX_PATH];                 TCHAR *ManfID;                 TCHAR *SerialNumber;                 BOOL RetVal = FALSE;                 DWORD GLE;                   // Note that either of the following works                 //_stprintf(VolumeName, _T("\\%s\\Vol:"), Disk);                 _stprintf(VolumeName, _T("\\%s"), Disk);                   hVol = CreateFile( Disk, GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);                   if( hVol != INVALID_HANDLE_VALUE )                 {                                 if(DeviceIoControl(hVol, IOCTL_DISK_GET_STORAGEID, (LPVOID)NULL, 0, &GetSizeStoreID, sizeof(STORAGE_IDENTIFICATION), &dwSize, NULL) == FALSE)                                 {                                                 GLE = GetLastError();                                                 if( GLE == ERROR_INSUFFICIENT_BUFFER )                                                 {                                                                 StoreID = (STORAGE_IDENTIFICATION *)malloc( GetSizeStoreID.dwSize );                                                                 if(DeviceIoControl(hVol, IOCTL_DISK_GET_STORAGEID, (LPVOID)NULL, 0, StoreID, GetSizeStoreID.dwSize, &dwSize, NULL) != FALSE)                                                                 {                                                                                 RETAILMSG( 1, (TEXT("DisplayDiskID: Flags %X\r\n"), StoreID->dwFlags ));                                                                                 if( !(StoreID->dwFlags & MANUFACTUREID_INVALID) )                                                                                 {                                                                                                 ManfID = (TCHAR *)((DWORD)StoreID + StoreID->dwManufactureIDOffset);                                                                                                 RETAILMSG( 1, (TEXT("DisplayDiskID: Manufacture ID %s\r\n"), ManfID ));                                                                                 }                                                                                 if( !(StoreID->dwFlags & SERIALNUM_INVALID) )                                                                                 {                                                                                                 SerialNumber = (TCHAR *)((DWORD)StoreID + StoreID->dwSerialNumOffset);                                                                                                 RETAILMSG( 1, (TEXT("DisplayDiskID: Serial Number %s\r\n"), SerialNumber ));                                                                                 }                                                                                 RetVal = TRUE;                                                                 }                                                                 else                                                                                 RETAILMSG( 1, (TEXT("DisplayDiskID: DeviceIoControl failed (%d)\r\n"), GLE));                                                                                                                                                 free(StoreID);                                                 }                                                 else                                                                 RETAILMSG( 1, (TEXT("No Disk Identifcation available for %s\r\n"), VolumeName ));                                 }                                 else                                                 RETAILMSG( 1, (TEXT("DisplayDiskID: DeviceIoControl succeeded (and shouldn't have)\r\n")));                                                                                 CloseHandle (hVol);                 }                 else                                 RETAILMSG( 1, (TEXT("DisplayDiskID: Failed to open volume (%s)\r\n"), VolumeName ));                   return RetVal; } Further testing showed that both \DSKx: and \DSKx:\Vol: work when calling CreateFile();   Copyright © 2010 – Bruce Eitman All Rights Reserved

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• Hierarchical View/ViewModel/Presenters in MVPVM

  - by Brian Flynn

  I've been working with MVVM for a while, but I've recently started using MVPVM and I want to know how to create hierarchial View/ViewModel/Presenter app using this pattern. In MVVM I would typically build my application using a hierarchy of Views and corresponding ViewModels e.g. I might define 3 views as follows: The View Models for these views would be as follows: public class AViewModel { public string Text { get { return "This is A!"; } } public object Child1 { get; set; } public object Child2 { get; set; } } public class BViewModel { public string Text { get { return "This is B!"; } } } public class CViewModel { public string Text { get { return "This is C!"; } } } In would then have some data templates to say that BViewModel and CViewModel should be presented using View B and View C: <DataTemplate DataType="{StaticResource local:BViewModel}"> <local:BView/> </DataTemplate> <DataTemplate DataType="{StaticResource local:CViewModel}"> <local:CView/> </DataTemplate> The final step would be to put some code in AViewModel that would assign values to Child1 and Child2: public AViewModel() { this.Child1 = new AViewModel(); this.Child2 = new BViewModel(); } The result of all this would be a screen that looks something like: Doing this in MVPVM would be fairly simple - simply moving the code in AViewModel's constructor to APresenter: public class APresenter { .... public void WireUp() { ViewModel.Child1 = new BViewModel(); ViewModel.Child2 = new CViewModel(); } } But If I want to have business logic for BViewModel and CViewModel I would need to have a BPresenter and a CPresenter - the problem is, Im not sure where the best place to put these are. I could store references to the presenter for AViewModel.Child1 and AViewModel.Child2 in APresenter i.e.: public class APresenter : IPresenter { private IPresenter child1Presenter; private IPresenter child2Presenter; public void WireUp() { child1Presenter = new BPresenter(); child1Presenter.WireUp(); child2Presenter = new CPresenter(); child2Presenter.WireUp(); ViewModel.Child1 = child1Presenter.ViewModel; ViewModel.Child2 = child2Presenter.ViewModel; } } But this solution seems inelegant compared to the MVVM approach. I have to keep track of both the presenter and the view model and ensure they stay in sync. If, for example, I wanted a button on View A, which, when clicked swapped the View's in Child1 and Child2, I might have a command that did the following: var temp = ViewModel.Child1; ViewModel.Child1 = ViewModel.Child2; ViewModel.Child2 = temp; This would work as far as swapping the view's on screen (assuming the correct Property Change notification code is in place), but now my APresenter.child1Presenter is pointing to the presenter for AViewModel.Child2, and APresenter.child2Presenter is pointing to the presenter for AViewModel.Child1. If something accesses APresenter.child1Presenter, any changes will actually happen to AViewModel.Child2. I can imagine this leading to all sorts of debugging fun. I know that I may be misunderstanding the pattern, and if this is the case a clarification of what Im doing wrong would be appreciated.

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• C# Proposal: Compile Time Static Checking Of Dynamic Objects

  - by Paulo Morgado

  C# 4.0 introduces a new type: dynamic. dynamic is a static type that bypasses static type checking. This new type comes in very handy to work with: The new languages from the dynamic language runtime. HTML Document Object Model (DOM). COM objects. Duck typing … Because static type checking is bypassed, this: dynamic dynamicValue = GetValue(); dynamicValue.Method(); is equivalent to this: object objectValue = GetValue(); objectValue .GetType() .InvokeMember( "Method", BindingFlags.InvokeMethod, null, objectValue, null); Apart from caching the call site behind the scenes and some dynamic resolution, dynamic only looks better. Any typing error will only be caught at run time. In fact, if I’m writing the code, I know the contract of what I’m calling. Wouldn’t it be nice to have the compiler do some static type checking on the interactions with these dynamic objects? Imagine that the dynamic object that I’m retrieving from the GetValue method, besides the parameterless method Method also has a string read-only Property property. This means that, from the point of view of the code I’m writing, the contract that the dynamic object returned by GetValue implements is: string Property { get; } void Method(); Since it’s a well defined contract, I could write an interface to represent it: interface IValue { string Property { get; } void Method(); } If dynamic allowed to specify the contract in the form of dynamic(contract), I could write this: dynamic(IValue) dynamicValue = GetValue(); dynamicValue.Method(); This doesn’t mean that the value returned by GetValue has to implement the IValue interface. It just enables the compiler to verify that dynamicValue.Method() is a valid use of dynamicValue and dynamicValue.OtherMethod() isn’t. If the IValue interface already existed for any other reason, this would be fine. But having a type added to an assembly just for compile time usage doesn’t seem right. So, dynamic could be another type construct. Something like this: dynamic DValue { string Property { get; } void Method(); } The code could now be written like this; DValue dynamicValue = GetValue(); dynamicValue.Method(); The compiler would never generate any IL or metadata for this new type construct. It would only thee used for compile type static checking of dynamic objects. As a consequence, it makes no sense to have public accessibility, so it would not be allowed. Once again, if the IValue interface (or any other type definition) already exists, it can be used in the dynamic type definition: dynamic DValue : IValue, IEnumerable, SomeClass { string Property { get; } void Method(); } Another added benefit would be IntelliSense. I’ve been getting mixed reactions to this proposal. What do you think? Would this be useful?

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