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  • C++ Simple thread with parameter (no .net)

    - by Marc Vollmer
    I've searched the internet for a while now and found different solutions but then all don't really work or are to complicated for my use. I used C++ until 2 years ago so it might be a bit rusty :D I'm currently writing a program that posts data to an URL. It only posts the data nothing else. For posting the data I use curl, but it blocks the main thread and while the first post is still running there will be a second post that should start. In the end there are about 5-6 post operations running at the same time. Now I want to push the posting with curl into another thread. One thread per post. The thread should get a string parameter with the content what to push. I'm currently stuck on this. Tried the WINAPI for windows but that crashes on reading the parameter. (the second thread is still running in my example while the main thread ended (waiting on system("pause")). It would be nice to have a multi plattform solution, because it will run under windows and linux! Heres my current code: #define CURL_STATICLIB #include <curl/curl.h> #include <curl/easy.h> #include <cstdlib> #include <iostream> #include <stdio.h> #include <stdlib.h> #include <string> #if defined(WIN32) #include <windows.h> #else //#include <pthread.h> #endif using namespace std; void post(string post) { // Function to post it to url CURL *curl; // curl object CURLcode res; // CURLcode object curl = curl_easy_init(); // init curl if(curl) { // is curl init curl_easy_setopt(curl, CURLOPT_URL, "http://10.8.27.101/api.aspx"); // set url string data = "api=" + post; // concat post data strings curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data.c_str()); // post data res = curl_easy_perform(curl); // execute curl_easy_cleanup(curl); // cleanup } else { cerr << "Failed to create curl handle!\n"; } } #if defined(WIN32) DWORD WINAPI thread(LPVOID data) { // WINAPI Thread string pData = *((string*)data); // convert LPVOID to string [THIS FAILES] post(pData); // post it with curl } #else // Linux version #endif void startThread(string data) { // FUnction to start the thread string pData = data; // some Test #if defined(WIN32) CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)thread, &pData, 0, NULL); // Start a Windows thread with winapi #else // Linux version #endif } int main(int argc, char *argv[]) { // The post data to send string postData = "test1234567890"; startThread(postData); // Start the thread system("PAUSE"); // Dont close the console window return EXIT_SUCCESS; } Has anyone a suggestion? Thanks for the help!

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  • Problems with Asynchronous UDP Sockets

    - by ihatenetworkcoding
    Hi, I'm struggling a bit with socket programming (something I'm not at all familiar with) and I can't find anything which helps from google or MSDN (awful). Apologies for the length of this. Basically I have an existing service which recieves and responds to requests over UDP. I can't change this at all. I also have a client within my webapp which dispatches and listens for responses to that service. The existing client I've been given is a singleton which creates a socket and an array of response slots, and then creates a background thread with an infinite looping method that makes "sock.Receive()" calls and pushes the data received into the slot array. All kinds of things about this seem wrong to me and the infinite thread breaks my unit testing so I'm trying to replace this service with one which makes it's it's send/receives asynchronously instead. Point 1: Is this the right approach? I want a non-blocking, scalable, thread-safe service. My first attempt is roughly like this, which sort of worked but the data I got back was always shorter than expected (i.e. the buffer did not have the number of bytes requested) and seemed to throw exceptions when processed. private Socket MyPreConfiguredSocket; public object Query() { //build a request this.MyPreConfiguredSocket.SendTo(MYREQUEST, packet.Length, SocketFlags.Multicast, this._target); IAsyncResult h = this._sock.BeginReceiveFrom(response, 0, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), this._sock); if (!h.AsyncWaitHandle.WaitOne(TIMEOUT)) { throw new Exception("Timed out"); } //process response data (always shortened) } private void ARecieve (IAsyncResult result) { int bytesreceived = (result as Socket).EndReceiveFrom(result, ref this._target); } My second attempt was based on more google trawling and this recursive pattern I frequently saw, but this version always times out! It never gets to ARecieve. public object Query() { //build a request this.MyPreConfiguredSocket.SendTo(MYREQUEST, packet.Length, SocketFlags.Multicast, this._target); State s = new State(this.MyPreConfiguredSocket); this.MyPreConfiguredSocket.BeginReceiveFrom(s.Buffer, 0, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), s); if (!s.Flag.WaitOne(10000)) { throw new Exception("Timed out"); } //always thrown //process response data } private void ARecieve (IAsyncResult result) { //never gets here! State s = (result as State); int bytesreceived = s.Sock.EndReceiveFrom(result, ref this._target); if (bytesreceived > 0) { s.Received += bytesreceived; this._sock.BeginReceiveFrom(s.Buffer, s.Received, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), s); } else { s.Flag.Set(); } } private class State { public State(Socket sock) { this._sock = sock; this._buffer = new byte[BUFFER_SIZE]; this._buffer.Initialize(); } public Socket Sock; public byte[] Buffer; public ManualResetEvent Flag = new ManualResetEvent(false); public int Received = 0; } Point 2: So clearly I'm getting something quite wrong. Point 3: I'm not sure if I'm going about this right. How does the data coming from the remote service even get to the right listening thread? Do I need to create a socket per request? Out of my comfort zone here. Need help.

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  • Partial view is not rendering within the main view it's contained (instead it's rendered in it's own page)?

    - by JaJ
    I have a partial view that is contained in a simple index view. When I try to add a new object to my model and update my partial view to display that new object along with existing objects the partial view is rendered outside the page that it's contained? I'm using AJAX to update the partial view but what is wrong with the following code? Model: public class Product { public int ID { get; set; } public string Name { get; set; } [DataType(DataType.Currency)] public decimal Price { get; set; } } public class BoringStoreContext { List<Product> results = new List<Product>(); public BoringStoreContext() { Products = new List<Product>(); Products.Add(new Product() { ID = 1, Name = "Sure", Price = (decimal)(1.10) }); Products.Add(new Product() { ID = 2, Name = "Sure2", Price = (decimal)(2.10) }); } public List<Product> Products {get; set;} } public class ProductIndexViewModel { public Product NewProduct { get; set; } public IEnumerable<Product> Products { get; set; } } Index.cshtml View: @model AjaxPartialPageUpdates.Models.ProductIndexViewModel @using (Ajax.BeginForm("Index_AddItem", new AjaxOptions { UpdateTargetId = "productList" })) { <div> @Html.LabelFor(model => model.NewProduct.Name) @Html.EditorFor(model => model.NewProduct.Name) </div> <div> @Html.LabelFor(model => model.NewProduct.Price) @Html.EditorFor(model => model.NewProduct.Price) </div> <div> <input type="submit" value="Add Product" /> </div> } <div id='productList'> @{ Html.RenderPartial("ProductListControl", Model.Products); } </div> ProductListControl.cshtml Partial View @model IEnumerable<AjaxPartialPageUpdates.Models.Product> <table> <!-- Render the table headers. --> <tr> <th>Name</th> <th>Price</th> </tr> <!-- Render the name and price of each product. --> @foreach (var item in Model) { <tr> <td>@Html.DisplayFor(model => item.Name)</td> <td>@Html.DisplayFor(model => item.Price)</td> </tr> } </table> Controller: public class HomeController : Controller { public ActionResult Index() { BoringStoreContext db = new BoringStoreContext(); ProductIndexViewModel viewModel = new ProductIndexViewModel { NewProduct = new Product(), Products = db.Products }; return View(viewModel); } public ActionResult Index_AddItem(ProductIndexViewModel viewModel) { BoringStoreContext db = new BoringStoreContext(); db.Products.Add(viewModel.NewProduct); return PartialView("ProductListControl", db.Products); } }

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  • CSS + jQuery - Unable to perform .toggle() and repeated jQueryTemplate Item [I must warn you this is a bit overwhelming]

    - by user1027620
    Okay here we go: Stream.html (Template file) <div class="streamItem clearfix"> <input type="button" /> <div class="clientStrip"> <img src="" alt="${Sender}" /> </div> <div class="clientView"> <a href="#" class="clientName">${Sender}</a> <p>${Value}</p> <p>${DateTime}</p> <div class="itemGadgets"> <ul> <li class="toggleInput">Value</li> <li></li> </ul> </div> <div class="inputContainer"> <input type="text" value="" /> </div> </div> </div> <div class="spacer" /> Default.aspx (jQuery) $('.toggleInput').live('click', function () { $(this).parent().parent() .find('.inputContainer').toggle(); $(this).parent().parent().find('.inputContainer') .find('input[type=text]').focus(); }); Update: The above has been changed to: $('.toggleInput').live('click', function () { $(this).closest(".clientView").find(".inputContainer").toggle() $(this).closest(".clientView").find(".inputContainer") .find('input[type=text]').focus(); }); Issues with jQuery: I have comments that belong to each .streamItem. My previous solution was to use ListView control as follows: <ItemTemplate> <asp:Panel ID="StreamItem" CssClass="StreamItem" runat="server"> ... <!-- Insert another nested ListView control here to load the comments for the parent stream. --> So as you can see, this is not a solution since I started using jQuery Templates and I am fetching the data using the following jQuery $.ajax method: $.ajax({ type: 'POST', url: 'Services.asmx/GetStream', data: "{}", contentType: 'application/json', success: function (Stream) { $.get('Templates/Stream.html', function (template) { $.tmpl(template, Stream.d).appendTo("#Stream"); }); } }); How can I resolve this without using the old ListView solution but by using jQuery Templates to load the comments whenever I am getting data for a specific stream? I am using a simple WebMethod to return my data as follows: [WebMethod] public List<Stream> GetStream() { List<Stream> Streams = Stream.GetRange(X, X, HttpContext.Current.User.Identity.Name); return Streams; } I am looking for a way to handle the .toggleInput click event. I need check if .Comments (a main container for the (to be comments container <div>)) has children (or more than one .commentItem). If so, then I need to show that .inputContainer and hide all the other .inputContainer divs with .Comments size() == 0 if they're visible. Please see the image below: Default.aspx (Partial CSS) div.streamItem div.clientView { float : left; width : 542px; } div.streamItem div.clientView p { margin : 5px 0 0 0; font-size : 10pt; } div.streamItem div.clientView div.inputContainer { display : none; /* Doesn't hide .inputContainer */ padding : 2px; background-color : #f1f1f1; } Issues with CSS: On page load, display: none; has no effect. That's it! If you're reading this I'd like to thank you for your time and thoughts! :)

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  • listview not updating,inserting

    - by raging_boner
    Data entered in textboxes is not getting updated in database. In debug mode I see that textbox1 and textbox2 in ItemUpdating event contain the same values as they had before calling ItemUpdating. Here's my listview control: <asp:ListView ID="ListView1" runat="server" onitemediting="ListView1_ItemEditing" onitemupdating="ListView1_ItemUpdating" oniteminserting="ListView1_ItemInserting"> //LayoutTemplate removed <ItemTemplate> <td align="center" valign="top"> <asp:Label ID="Label2" runat="server" Text='<%#Eval("id")%>'></asp:Label><br /> <asp:Label ID="Label3" runat="server" Text='<%#Eval("text1")%>'></asp:Label> </td> <td> <asp:LinkButton ID="LinkButton2" CommandName="Edit" runat="server">Edit</asp:LinkButton> <asp:LinkButton ID="LinkButton4" CommandName="Delete" runat="server">Delete</asp:LinkButton> </td> </ItemTemplate> <EditItemTemplate> <td align="center" valign="top"> <asp:Label ID="Label1" runat="server" Text='<%#Eval("id")%>'></asp:Label> <asp:TextBox ID="TextBox1" runat="server" Text='<%#Eval("text1")%>' TextMode="MultiLine" /> <asp:TextBox ID="TextBox2" runat="server" Text='<%#Eval("text2")%>' Height="100" TextMode="MultiLine" /> <asp:LinkButton ID="LinkButton1" CommandName="Update" CommandArgument='<%# Eval("id")%>' runat="server">Update</asp:LinkButton> <asp:LinkButton ID="LinkButton5" CommandName="Cancel" runat="server">Cancel</asp:LinkButton> </td> </EditItemTemplate> <InsertItemTemplate> <td align="center" valign="top"> <asp:TextBox ID="TextBox3" runat="server" TextMode="MultiLine" Height="100"></asp:TextBox> <asp:TextBox ID="TextBox4" runat="server" Height="100" TextMode="MultiLine"></asp:TextBox><br/> <asp:LinkButton ID="LinkButton3" runat="server">Insert</asp:LinkButton> </td> </InsertItemTemplate> </asp:ListView> Codebehind file: protected void ListView1_ItemEditing(object sender, ListViewEditEventArgs e) { ListView1.EditIndex = e.NewEditIndex; BindList(); } protected void ListView1_ItemUpdating(object sender, ListViewUpdateEventArgs e) { ListViewItem myItem = ListView1.Items[ListView1.EditIndex]; Label id = (Label)myItem.FindControl("Label1"); int dbid = int.Parse(id.Text); TextBox text1 = (TextBox)myItem.FindControl("Textbox1"); TextBox text2 = (TextBox)myItem.FindControl("Textbox2"); //tried to work withNewValues below, but they don't work, "null reference" error is being thrown //text1.Text = e.NewValues["text1"].ToString(); //text2.Text = e.NewValues["text2"].ToString(); //odbc connection routine removed. //i know that there should be odbc parameteres: comm = new OdbcCommand("UPDATE table SET text1 = '" + text1.Text + "', text2 = '" + text2.Text + "' WHERE id = '" + dbid + "'", connection); comm.ExecuteNonQuery(); conn.Close(); ListView1.EditIndex = -1; //here I databind ListView1 } What's wrong with updating of text1.Text, text2.Text in ItemUpdating event? Should I use e.NewValues property? If so, how to use it? Thanks in advance for any help.

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  • Unable to get my master & details gridview to work.

    - by Javier
    I'm unable to get this to work. I'm very new at programming and would appreciate any help on this. <%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> protected void Page_Load(object sender, EventArgs e) { } protected void DataGridSqlDataSource_Selecting(object sender, SqlDataSourceSelectingEventArgs e) { } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> <asp:SqlDataSource ID="DataGrid2SqlDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:JobPostings1ConnectionString %>" SelectCommand="SELECT [Jobs_PK], [Position_Title], [Educ_Level], [Grade], [JP_Description], [Job_Status], [Position_ID] FROM [Jobs]" FilterExpression="Jobs_PK='@Jobs_PK'"> <filterparameters> <asp:ControlParameter Name="Jobs_PK" ControlId="GridView1" PropertyName="SelectedValue" /> </filterparameters> </asp:SqlDataSource> <asp:SqlDataSource ID="DataGridSqlDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:JobPostings1ConnectionString %>" SelectCommand="SELECT [Position_Title], [Jobs_PK] FROM [Jobs]" onselecting="DataGridSqlDataSource_Selecting"> </asp:SqlDataSource> <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Jobs_PK" DataSourceID="DataGridSqlDataSource" AllowPaging="True" AutoGenerateSelectButton="True" SelectedIndex="0" Width="100px"> <Columns> <asp:BoundField DataField="Position_Title" HeaderText="Position_Title" SortExpression="Position_Title" /> <asp:BoundField DataField="Jobs_PK" HeaderText="Jobs_PK" InsertVisible="False" ReadOnly="True" SortExpression="Jobs_PK" /> </Columns> </asp:GridView> <br /> <asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="False" DataKeyNames="Jobs_PK" DataSourceID="DataGrid2SqlDataSource" Height="50px" Width="125px"> <Fields> <asp:BoundField DataField="Jobs_PK" HeaderText="Jobs_PK" InsertVisible="False" ReadOnly="True" SortExpression="Jobs_PK" /> <asp:BoundField DataField="Position_Title" HeaderText="Position_Title" SortExpression="Position_Title" /> <asp:BoundField DataField="Educ_Level" HeaderText="Educ_Level" SortExpression="Educ_Level" /> <asp:BoundField DataField="Grade" HeaderText="Grade" SortExpression="Grade" /> <asp:BoundField DataField="JP_Description" HeaderText="JP_Description" SortExpression="JP_Description" /> <asp:BoundField DataField="Job_Status" HeaderText="Job_Status" SortExpression="Job_Status" /> <asp:BoundField DataField="Position_ID" HeaderText="Position_ID" SortExpression="Position_ID" /> </Fields> </asp:DetailsView> </div> </form> </body> error message: Cannot perform '=' operation on System.Int32 and System.String. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.EvaluateException: Cannot perform '=' operation on System.Int32 and System.String.

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  • Referencing variables in a structure / C++

    - by user1628622
    Below, I provided a minimal example of code I created. I managed to get this code working, but I'm not sure if the practice being employed is sound. In essence, what I am trying to do is have the 'Parameter' class reference select elements in the 'States' class, so variables in States can be changed via Parameters. Questions I have: is the approach taken OK? If not, is there a better way to achieve what I am aiming for? Example code: struct VAR_TYPE{ public: bool is_fixed; // If is_fixed = true, then variable is a parameter double value; // Numerical value std::string name; // Description of variable (to identify it by name) }; struct NODE{ public: VAR_TYPE X, Y, Z; /* VAR_TYPE is a structure of primitive types */ }; class States{ private: std::vector <NODE_ptr> node; // shared ptr to struct NODE std::vector <PROP_DICTIONARY_ptr> property; // CAN NOT be part of Parameter std::vector <ELEMENT_ptr> element; // CAN NOT be part of Parameter public: /* ect */ void set_X_reference ( Parameter &T , int i ) { T.push_var( &node[i]->X ); } void set_Y_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Y ); } void set_Z_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Z ); } bool get_node_bool_X( int i ) { return node[i]->X.is_fixed; } // repeat for Y and Z }; class Parameter{ private: std::vector <VAR_TYPE*> var; public: /* ect */ }; int main(){ States S; Parameter P; /* Here I initialize and set S, and do other stuff */ // Now I assign components in States to Parameters for(int n=0 ; n<S.size_of_nodes() ; n++ ){ if ( S.get_node_bool_X(n)==true ){ S.set_X_reference ( P , n ); }; // repeat if statement for Y and Z }; /* Now P points selected to data in S, and I can * modify the contents of S through P */ return 0; }; Update The reason this issue cropped up is I am working with Fortran legacy code. To sum up this Fotran code - it's a numerical simulation of a flight vehicle. This code has a fairly rigid procedural framework one must work within, which comes with a pre-defined list of allowable Fortran types. The Fortran glue code can create an instance of a C++ object (in actuality, a reference from the perspective of Fortran), but is not aware what is contained in it (other means are used to extract C++ data into Fortran). The problem that I encountered is when a C++ module is dynamically linked to the Fortran glue code, C++ objects have to be initialized each instance the C++ code is called. This happens by virtue of how the Fortran template is defined. To avoid this cycle of re-initializing objects, I plan to use 'State' as a container class. The Fortran code allows a 'State' object, which has an arbitrary definition; but I plan to use it to harness all relevant information about the model. The idea is to use the Parameters class (which is exposed and updated by the Fortran code) to update variables in States.

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  • Testing shared memory ,strange thing happen

    - by barfatchen
    I have 2 program compiled in 4.1.2 running in RedHat 5.5 , It is a simple job to test shared memory , shmem1.c like following : #define STATE_FILE "/program.shared" #define NAMESIZE 1024 #define MAXNAMES 100 typedef struct { char name[MAXNAMES][NAMESIZE]; int heartbeat ; int iFlag ; } SHARED_VAR; int main (void) { int first = 0; int shm_fd; static SHARED_VAR *conf; if((shm_fd = shm_open(STATE_FILE, (O_CREAT | O_EXCL | O_RDWR), (S_IREAD | S_IWRITE))) > 0 ) { first = 1; /* We are the first instance */ } else if((shm_fd = shm_open(STATE_FILE, (O_CREAT | O_RDWR), (S_IREAD | S_IWRITE))) < 0) { printf("Could not create shm object. %s\n", strerror(errno)); return errno; } if((conf = mmap(0, sizeof(SHARED_VAR), (PROT_READ | PROT_WRITE), MAP_SHARED, shm_fd, 0)) == MAP_FAILED) { return errno; } if(first) { for(idx=0;idx< 1000000000;idx++) { conf->heartbeat = conf->heartbeat + 1 ; } } printf("conf->heartbeat=(%d)\n",conf->heartbeat) ; close(shm_fd); shm_unlink(STATE_FILE); exit(0); }//main And shmem2.c like following : #define STATE_FILE "/program.shared" #define NAMESIZE 1024 #define MAXNAMES 100 typedef struct { char name[MAXNAMES][NAMESIZE]; int heartbeat ; int iFlag ; } SHARED_VAR; int main (void) { int first = 0; int shm_fd; static SHARED_VAR *conf; if((shm_fd = shm_open(STATE_FILE, (O_RDWR), (S_IREAD | S_IWRITE))) < 0) { printf("Could not create shm object. %s\n", strerror(errno)); return errno; } ftruncate(shm_fd, sizeof(SHARED_VAR)); if((conf = mmap(0, sizeof(SHARED_VAR), (PROT_READ | PROT_WRITE), MAP_SHARED, shm_fd, 0)) == MAP_FAILED) { return errno; } int idx ; for(idx=0;idx< 1000000000;idx++) { conf->heartbeat = conf->heartbeat + 1 ; } printf("conf->heartbeat=(%d)\n",conf->heartbeat) ; close(shm_fd); exit(0); } After compiled : gcc shmem1.c -lpthread -lrt -o shmem1.exe gcc shmem2.c -lpthread -lrt -o shmem2.exe And Run both program almost at the same time with 2 terminal : [test]$ ./shmem1.exe First creation of the shm. Setting up default values conf->heartbeat=(840825951) [test]$ ./shmem2.exe conf->heartbeat=(1215083817) I feel confused !! since shmem1.c is a loop 1,000,000,000 times , how can it be possible to have a answer like 840,825,951 ? I run shmem1.exe and shmem2.exe this way,most of the results are conf-heartbeat will larger than 1,000,000,000 , but seldom and randomly , I will see result conf-heartbeat will lesser than 1,000,000,000 , either in shmem1.exe or shmem2.exe !! if run shmem1.exe only , it is always print 1,000,000,000 , my question is , what is the reason cause conf-heartbeat=(840825951) in shmem1.exe ? Update: Although not sure , but I think I figure it out what is going on , If shmem1.exe run 10 times for example , then conf-heartbeat = 10 , in this time shmem1.exe take a rest and then back , shmem1.exe read from shared memory and conf-heartbeat = 8 , so shmem1.exe will continue from 8 , why conf-heartbeat = 8 ? I think it is because shmem2.exe update the shared memory data to 8 , shmem1.exe did not write 10 back to shared memory before it took a rest ....that is just my theory... i don't know how to prove it !!

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  • ODBC in SSIS 2012

    - by jamiet
    In August 2011 the SQL Server client team published a blog post entitled Microsoft is Aligning with ODBC for Native Relational Data Access in which they basically said "OLE DB is the past, ODBC is the future. Deal with it.". From that blog post:We encourage you to adopt ODBC in the development of your new and future versions of your application. You don’t need to change your existing applications using OLE DB, as they will continue to be supported on Denali throughout its lifecycle. While this gives you a large window of opportunity for changing your applications before the deprecation goes into effect, you may want to consider migrating those applications to ODBC as a part of your future roadmap.I recently undertook a project using SSIS2012 and heeded that advice by opting to use ODBC Connection Managers rather than OLE DB Connection Managers. Unfortunately my finding was that the ODBC Connection Manager is not yet ready for primetime use in SSIS 2012. The main issue I found was that you can't populate an Object variable with a recordset when using an Execute SQL Task connecting to an ODBC data source; any attempt to do so will result in an error:"Disconnected recordsets are not available from ODBC connections." I have filed a bug on Connect at ODBC Connection Manager does not have same funcitonality as OLE DB. For this reason I strongly recommend that you don't make the move to ODBC Connection Managers in SSIS just yet - best to wait for the next version of SSIS before doing that.I found another couple of issues with the ODBC Connection Manager that are worth keeping in mind:It doesn't recognise System Data Source Names (DSNs), only User DSNs (bug filed at ODBC System DSNs are not available in the ODBC Connection Manager)  UPDATE: According to a comment on that Connect item this may only be a problem on 64bit.In the OLE DB Connection Manager parameter ordinals are 0-based, in the ODBC Connection Manager they are 1-based (oh I just can't wait for the upgrade mess that ensues from this one!!!)You have been warned!@jamiet

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  • MVVM for Dummies

    - by Martin Hinshelwood
    I think that I have found one of the best articles on MVVM that I have ever read: http://jmorrill.hjtcentral.com/Home/tabid/428/EntryId/432/MVVM-for-Tarded-Folks-Like-Me-or-MVVM-and-What-it-Means-to-Me.aspx This article sums up what is in MVVM and what is outside of MVVM. Note, when I and most other people say MVVM, they really mean MVVM, Commanding, Dependency Injection + any other Patterns you need to create your application. In WPF a lot of use is made of the Decorator and Behaviour pattern as well. The goal of all of this is to have pure separation of concerns. This is what every code behind file of every Control / Window / Page  should look like if you are engineering your WPF and Silverlight correctly: C# – Ideal public partial class IdealView : UserControl { public IdealView() { InitializeComponent(); } } Figure: This is the ideal code behind for a Control / Window / Page when using MVVM. C# – Compromise, but works public partial class IdealView : UserControl { public IdealView() { InitializeComponent(); this.DataContext = new IdealViewModel(); } } Figure: This is a compromise, but the best you can do without Dependency Injection VB.NET – Ideal Partial Public Class ServerExplorerConnectView End Class Figure: This is the ideal code behind for a Control / Window / Page when using MVVM. VB.NET – Compromise, but works Partial Public Class ServerExplorerConnectView Private Sub ServerExplorerConnectView_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded Me.DataContext = New ServerExplorerConnectViewModel End Sub End Class Figure: This is a compromise, but the best you can do without Dependency Injection Technorati Tags: MVVM,.NET,WPF,Silverlight

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  • Unable to update the EntitySet because it has a DefiningQuery and no &lt;UpdateFunction&gt; element

    - by Harish Ranganathan
    When working with ADO.NET Entity Data Model, its often common that we generate entity schema for more than a single table from our Database.  With Entity Model generation automated with Visual Studio support, it becomes even tempting to create and work entity models to achieve an object mapping relationship. One of the errors that you might hit while trying to update an entity set either programmatically using context.SaveChanges or while using the automatic insert/update code generated by GridView etc., is “Unable to update the EntitySet <EntityName> because it has a DefiningQuery and no <UpdateFunction> element exists in the <ModificationFunctionMapping> element to support the current operation” While the description is pretty lengthy, the immediate thing that would come to our mind is to open our the entity model generated code and see if you can update it accordingly. However, the first thing to check if that, if the Entity Set is generated from a table, whether the Table defines a primary key.  Most of the times, we create tables with primary keys.  But some reference tables and tables which don’t have a primary key cannot be updated using the context of Entity and hence it would throw this error.  Unless it is a View, in which case, the default model is read-only, most of the times the above error occurs since there is no primary key defined in the table. There are other reasons why this error could popup which I am not going into for the sake of simplicity of the post.  If you find something new, please feel free to share it in comments. Hope this helps. Cheers !!!

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  • Adding a hyperlink in a client report definition file (RDLC)

    - by rajbk
    This post shows you how to add a hyperlink to your RDLC report. In a previous post, I showed you how to create an RDLC report. We have been given the requirement to the report we created earlier, the Northwind Product report, to add a column that will contain hyperlinks which are unique per row.  The URLs will be RESTful with the ProductID at the end. Clicking on the URL will take them to a website like so: http://localhost/products/3  where 3 is the primary key of the product row clicked on. To start off, open the RDLC and add a new column to the product table.   Add text to the header (Details) and row (Product Website). Right click on the row (not header) and select “TextBox properties” Select Action – Go to URL. You could hard code a URL here but what we need is a URL that changes based on the ProductID.   Click on the expression button (fx) The expression builder gives you access to several functions and constants including the fields in your dataset. See this reference for more details: Common Expressions for ReportViewer Reports. Add the following expression: = "http://localhost/products/" & Fields!ProductID.Value Click OK to exit the Expression Builder. The report will not render because hyperlinks are disabled by default in the ReportViewer control. To enable it, add the following in your page load event (where rvProducts is the ID of your ReportViewerControl): protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { rvProducts.LocalReport.EnableHyperlinks = true; } } We want our links to open in a new window so set the HyperLinkTarget property of the ReportViewer control to “_blank”   We are done adding hyperlinks to our report. Clicking on the links for each product pops open a new windows. The URL has the ProductID added at the end. Enjoy!

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  • SQL SERVER – Generate Report for Index Physical Statistics – SSMS

    - by pinaldave
    Few days ago, I wrote about SQL SERVER – Out of the Box – Activity and Performance Reports from SSSMS (Link). A user asked me a question regarding if we can use similar reports to get the detail about Indexes. Yes, it is possible to do the same. There are similar type of reports are available at Database level, just like those available at the Server Instance level. You can right click on Database name and click Reports. Under Standard Reports, you will find following reports. Disk Usage Disk Usage by Top Tables Disk Usage by Table Disk Usage by Partition Backup and Restore Events All Transactions All Blocking Transactions Top Transactions by Age Top Transactions by Blocked Transactions Count Top Transactions by Locks Count Resource Locking Statistics by Objects Object Execute Statistics Database Consistency history Index Usage Statistics Index Physical Statistics Schema Change history User Statistics Select the Reports with name Index Physical Statistics. Once click, a report containing all the index names along with other information related to index will be visible, e.g. Index Type and number of partitions. One column that caught my interest was Operation Recommended. In some place, it suggested that index needs to be rebuilt. It is also possible to click and expand the column of partitions and see additional details about index as well. DBA and Developers who just want to have idea about how your index is and its physical statistics can use this tool. Click to Enlarge Note: Please note that I will rebuild my indexes just because this report is recommending it. There are many other parameters you need to consider before rebuilding indexes. However, this tool gives you the accurate stats of your index and it can be right away exported to Excel or PDF writing by clicking on the report. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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  • Export data to Excel from Silverlight/WPF DataGrid

    - by outcoldman
    Data export from DataGrid to Excel is very common task, and it can be solved with different ways, and chosen way depend on kind of app which you are design. If you are developing app for enterprise, and it will be installed on several computes, then you can to advance a claim (system requirements) with which your app will be work for client. Or customer will advance system requirements on which your app should work. In this case you can use COM for export (use infrastructure of Excel or OpenOffice). This approach will give you much more flexibility and give you possibility to use all features of Excel app. About this approach I’ll speak below. Other way – your app is for personal use, it can be installed on any home computer, in this case it is not good to ask user to install MS Office or OpenOffice just for using your app. In this way you can use foreign tools for export, or export to xml/html format which MS Office can read (this approach used by JIRA). But in this case will be more difficult to satisfy user tasks, like create document with landscape rotation and with defined fields for printing. At this article I'll show you how to work with Excel object from .NET 4 and Silverlight 4 with dynamic objects and give you an approach which allow you to export data from DataGrid Silverlight and WPF controls. Read more...

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  • Solution: Testing Web Services with MSTest on Team Build

    - by Martin Hinshelwood
    Guess what. About 20 minutes after I fixed the build, Allan broke it again! Update: 4th March 2010 – After having huge problems getting this working I read Billy Wang’s post which showed me the light. The problem here is that even though the test passes locally it will not during an Automated Build. When you send your tests to the build server it does not understand that you want to spin up the web site and run tests against that! When you run the test in Visual Studio it spins up the web site anyway, but would you expect your test to pass if you told the website not to spin up? Of course not. So, when you send the code to the build server you need to tell it what to spin up. First, the best way to get the parameters you need is to right click on the method you want to test and select “Create Unit Test”. This will detect wither you are running in IIS or ASP.NET Development Server or None, and create the relevant tags. Figure: Right clicking on “SaveDefaultProjectFile” will produce a context menu with “Create Unit tests…” on it. If you use this option it will AutoDetect most of the Attributes that are required. /// <summary> ///A test for SSW.SQLDeploy.SilverlightUI.Web.Services.IProfileService.SaveDefaultProjectFile ///</summary> // TODO: Ensure that the UrlToTest attribute specifies a URL to an ASP.NET page (for example, // http://.../Default.aspx). This is necessary for the unit test to be executed on the web server, // whether you are testing a page, web service, or a WCF service. [TestMethod()] [HostType("ASP.NET")] [AspNetDevelopmentServerHost("D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web", "/")] [UrlToTest("http://localhost:3100/")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] public void SaveDefaultProjectFileTest() { IProfileService target = new ProfileService(); // TODO: Initialize to an appropriate value string strComputerName = string.Empty; // TODO: Initialize to an appropriate value bool expected = false; // TODO: Initialize to an appropriate value bool actual; actual = target.SaveDefaultProjectFile(strComputerName); Assert.AreEqual(expected, actual); Assert.Inconclusive("Verify the correctness of this test method."); } Figure: Auto created code that shows the attributes required to run correctly in IIS or in this case ASP.NET Development Server If you are a purist and don’t like creating unit tests like this then you just need to add the three attributes manually. HostType – This attribute specified what host to use. Its an extensibility point, so you could write your own. Or you could just use “ASP.NET”. UrlToTest – This specifies the start URL. For most tests it does not matter which page you call, as long as it is a valid page otherwise your test may not run on the server, but may pass anyway. AspNetDevelopmentServerHost – This is a nasty one, it is only used if you are using ASP.NET Development Host and is unnecessary if you are using IIS. This sets the host settings and the first value MUST be the physical path to the root of your web application. OK, so all that was rubbish and I could not get anything working using the MSDN documentation. Google provided very little help until I ran into Billy Wang’s post  and I heard that heavenly music that all developers hear when understanding dawns that what they have been doing up until now is just plain stupid. I am sure that the above will work when I am doing Web Unit Tests, but there is a much easier way when doing web services. You need to add the AspNetDevelopmentServer attribute to your code. This will tell MSTest to spin up an ASP.NET Development server to host the service. Specify the path to the web application you want to use. [AspNetDevelopmentServer("WebApp1", "D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: This AspNetDevelopmentServer will make sure that the specified web application is launched. Now we can run the test and have it pass, but if the dynamically assigned ASP.NET Development server port changes what happens to the details in your app.config that was generated when creating a reference to the web service? Well, it would be wrong and the test would fail. This is where Billy’s helper method comes in. Once you have created an instance of your service call, and it has loaded the config, but before you make any calls to it you need to go in and dynamically set the Endpoint address to the same address as your dynamically hosted Web Application. using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.VisualStudio.TestTools.UnitTesting; using System.Reflection; using System.ServiceModel.Description; using System.ServiceModel; namespace SSW.SQLDeploy.Test { class WcfWebServiceHelper { public static bool TryUrlRedirection(object client, TestContext context, string identifier) { bool result = true; try { PropertyInfo property = client.GetType().GetProperty("Endpoint"); string webServer = context.Properties[string.Format("AspNetDevelopmentServer.{0}", identifier)].ToString(); Uri webServerUri = new Uri(webServer); ServiceEndpoint endpoint = (ServiceEndpoint)property.GetValue(client, null); EndpointAddressBuilder builder = new EndpointAddressBuilder(endpoint.Address); builder.Uri = new Uri(endpoint.Address.Uri.OriginalString.Replace(endpoint.Address.Uri.Authority, webServerUri.Authority)); endpoint.Address = builder.ToEndpointAddress(); } catch (Exception e) { context.WriteLine(e.Message); result = false; } return result; } } } Figure: This fixes a problem with the URL in your web.config not being the same as the dynamically hosted ASP.NET Development server port. We can now add a call to this method after we created the Proxy object and change the Endpoint for the Service to the correct one. This process is wrapped in an assert as if it fails there is no point in continuing. [AspNetDevelopmentServer("WebApp1", D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); Assert.IsTrue(WcfWebServiceHelper.TryUrlRedirection(target, TestContext, "WebApp1")); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: Editing the Endpoint from the app.config on the fly to match the dynamically hosted ASP.NET Development Server URL and port is now easy. As you can imagine AspNetDevelopmentServer poses some problems of you have multiple developers. What are the chances of everyone using the same location to store the source? What about if you are using a build server, how do you tell MSTest where to look for the files? To the rescue is a property called" “%PathToWebRoot%” which is always right on the build server. It will always point to your build drop folder for your solutions web sites. Which will be “\\tfs.ssw.com.au\BuildDrop\[BuildName]\Debug\_PrecompiledWeb\” or whatever your build drop location is. So lets change the code above to add this. [AspNetDevelopmentServer("WebApp1", "%PathToWebRoot%\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); Assert.IsTrue(WcfWebServiceHelper.TryUrlRedirection(target, TestContext, "WebApp1")); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: Adding %PathToWebRoot% to the AspNetDevelopmentServer path makes it work everywhere. Now we have another problem… this will ONLY run on the build server and will fail locally as %PathToWebRoot%’s default value is “C:\Users\[profile]\Documents\Visual Studio 2010\Projects”. Well this sucks… How do we get the test to run on any build server and any developer laptop. Open “Tools | Options | Test Tools | Test Execution” in Visual Studio and you will see a field called “Web application root directory”. This is where you override that default above. Figure: You can override the default website location for tests. In my case I would put in “D:\Workspaces\SSW\SSW\SqlDeploy\DEV\Main” and all the developers working with this branch would put in the folder that they have mapped. Can you see a problem? What is I create a “$/SSW/SqlDeploy/DEV/34567” branch from Main and I want to run tests in there. Well… I would have to change the value above. This is not ideal, but as you can put your projects anywhere on a computer, it has to be done. Conclusion Although this looks convoluted and complicated there are real problems being solved here that mean that you have a test ANYWHERE solution. Any build server, any Developer workstation. Resources: http://billwg.blogspot.com/2009/06/testing-wcf-web-services.html http://tough-to-find.blogspot.com/2008/04/testing-asmx-web-services-in-visual.html http://msdn.microsoft.com/en-us/library/ms243399(VS.100).aspx http://blogs.msdn.com/dscruggs/archive/2008/09/29/web-tests-unit-tests-the-asp-net-development-server-and-code-coverage.aspx http://www.5z5.com/News/?543f8bc8b36b174f Technorati Tags: VS2010,MSTest,Team Build 2010,Team Build,Visual Studio,Visual Studio 2010,Visual Studio ALM,Team Test,Team Test 2010

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

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

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  • SQL SERVER – Shrinking NDF and MDF Files – Readers’ Opinion

    - by pinaldave
    Previously, I had written a blog post about SQL SERVER – Shrinking NDF and MDF Files – A Safe Operation. After that, I have written the following blog post that talks about the advantage and disadvantage of Shrinking and why one should not be Shrinking a file SQL SERVER – SHRINKFILE and TRUNCATE Log File in SQL Server 2008. On this subject, SQL Server Expert Imran Mohammed left an excellent comment. I just feel that his comment is worth a big article itself. For everybody to read his wonderful explanation, I am posting this blog post here. Thanks Imran! Shrinking Database always creates performance degradation and increases fragmentation in the database. I suggest that you keep that in mind before you start reading the following comment. If you are going to say Shrinking Database is bad and evil, here I am saying it first and loud. Now, the comment of Imran is written while keeping in mind only the process showing how the Shrinking Database Operation works. Imran has already explained his understanding and requests further explanation. I have removed the Best Practices section from Imran’s comments, as there are a few corrections. Comments from Imran - Before I explain to you the concept of Shrink Database, let us understand the concept of Database Files. When we create a new database inside the SQL Server, it is typical that SQl Server creates two physical files in the Operating System: one with .MDF Extension, and another with .LDF Extension. .MDF is called as Primary Data File. .LDF is called as Transactional Log file. If you add one or more data files to a database, the physical file that will be created in the Operating System will have an extension of .NDF, which is called as Secondary Data File; whereas, when you add one or more log files to a database, the physical file that will be created in the Operating System will have the same extension as .LDF. The questions now are, “Why does a new data file have a different extension (.NDF)?”, “Why is it called as a secondary data file?” and, “Why is .MDF file called as a primary data file?” Answers: Note: The following explanation is based on my limited knowledge of SQL Server, so experts please do comment. A data file with a .MDF extension is called a Primary Data File, and the reason behind it is that it contains Database Catalogs. Catalogs mean Meta Data. Meta Data is “Data about Data”. An example for Meta Data includes system objects that store information about other objects, except the data stored by the users. sysobjects stores information about all objects in that database. sysindexes stores information about all indexes and rows of every table in that database. syscolumns stores information about all columns that each table has in that database. sysusers stores how many users that database has. Although Meta Data stores information about other objects, it is not the transactional data that a user enters; rather, it’s a system data about the data. Because Primary Data File (.MDF) contains important information about the database, it is treated as a special file. It is given the name Primary Data file because it contains the Database Catalogs. This file is present in the Primary File Group. You can always create additional objects (Tables, indexes etc.) in the Primary data file (This file is present in the Primary File group), by mentioning that you want to create this object under the Primary File Group. Any additional data file that you add to the database will have only transactional data but no Meta Data, so that’s why it is called as the Secondary Data File. It is given the extension name .NDF so that the user can easily identify whether a specific data file is a Primary Data File or a Secondary Data File(s). There are many advantages of storing data in different files that are under different file groups. You can put your read only in the tables in one file (file group) and read-write tables in another file (file group) and take a backup of only the file group that has read the write data, so that you can avoid taking the backup of a read-only data that cannot be altered. Creating additional files in different physical hard disks also improves I/O performance. A real-time scenario where we use Files could be this one: Let’s say you have created a database called MYDB in the D-Drive which has a 50 GB space. You also have 1 Database File (.MDF) and 1 Log File on D-Drive and suppose that all of that 50 GB space has been used up and you do not have any free space left but you still want to add an additional space to the database. One easy option would be to add one more physical hard disk to the server, add new data file to MYDB database and create this new data file in a new hard disk then move some of the objects from one file to another, and put the file group under which you added new file as default File group, so that any new object that is created gets into the new files, unless specified. Now that we got a basic idea of what data files are, what type of data they store and why they are named the way they are, let’s move on to the next topic, Shrinking. First of all, I disagree with the Microsoft terminology for naming this feature as “Shrinking”. Shrinking, in regular terms, means to reduce the size of a file by means of compressing it. BUT in SQL Server, Shrinking DOES NOT mean compressing. Shrinking in SQL Server means to remove an empty space from database files and release the empty space either to the Operating System or to SQL Server. Let’s examine this through an example. Let’s say you have a database “MYDB” with a size of 50 GB that has a free space of about 20 GB, which means 30GB in the database is filled with data and the 20 GB of space is free in the database because it is not currently utilized by the SQL Server (Database); it is reserved and not yet in use. If you choose to shrink the database and to release an empty space to Operating System, and MIND YOU, you can only shrink the database size to 30 GB (in our example). You cannot shrink the database to a size less than what is filled with data. So, if you have a database that is full and has no empty space in the data file and log file (you don’t have an extra disk space to set Auto growth option ON), YOU CANNOT issue the SHRINK Database/File command, because of two reasons: There is no empty space to be released because the Shrink command does not compress the database; it only removes the empty space from the database files and there is no empty space. Remember, the Shrink command is a logged operation. When we perform the Shrink operation, this information is logged in the log file. If there is no empty space in the log file, SQL Server cannot write to the log file and you cannot shrink a database. Now answering your questions: (1) Q: What are the USEDPAGES & ESTIMATEDPAGES that appear on the Results Pane after using the DBCC SHRINKDATABASE (NorthWind, 10) ? A: According to Books Online (For SQL Server 2000): UsedPages: the number of 8-KB pages currently used by the file. EstimatedPages: the number of 8-KB pages that SQL Server estimates the file could be shrunk down to. Important Note: Before asking any question, make sure you go through Books Online or search on the Google once. The reasons for doing so have many advantages: 1. If someone else already has had this question before, chances that it is already answered are more than 50 %. 2. This reduces your waiting time for the answer. (2) Q: What is the difference between Shrinking the Database using DBCC command like the one above & shrinking it from the Enterprise Manager Console by Right-Clicking the database, going to TASKS & then selecting SHRINK Option, on a SQL Server 2000 environment? A: As far as my knowledge goes, there is no difference, both will work the same way, one advantage of using this command from query analyzer is, your console won’t be freezed. You can do perform your regular activities using Enterprise Manager. (3) Q: What is this .NDF file that is discussed above? I have never heard of it. What is it used for? Is it used by end-users, DBAs or the SERVER/SYSTEM itself? A: .NDF File is a secondary data file. You never heard of it because when database is created, SQL Server creates database by default with only 1 data file (.MDF) and 1 log file (.LDF) or however your model database has been setup, because a model database is a template used every time you create a new database using the CREATE DATABASE Command. Unless you have added an extra data file, you will not see it. This file is used by the SQL Server to store data which are saved by the users. Hope this information helps. I would like to as the experts to please comment if what I understand is not what the Microsoft guys meant. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Readers Contribution, Readers Question, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Employee Info Starter Kit - Visual Studio 2010 and .NET 4.0 Version (4.0.0) Available

    - by joycsharp
    Employee Info Starter Kit is a ASP.NET based web application, which includes very simple user requirements, where we can create, read, update and delete (crud) the employee info of a company. Based on just a database table, it explores and solves all major problems in web development architectural space.  This open source starter kit extensively uses major features available in latest Visual Studio, ASP.NET and Sql Server to make robust, scalable, secured and maintanable web applications quickly and easily. Since it's first release, this starter kit achieved a huge popularity in web developer community and includes 1,40,000+ download from project web site. Visual Studio 2010 and .NET 4.0 came up with lots of exciting features to make software developers life easier.  A new version (v4.0.0) of Employee Info Starter Kit is now available in both MSDN Code Gallery and CodePlex. Chckout the latest version of this starter kit to enjoy cool features available in Visual Studio 2010 and .NET 4.0. [ Release Notes ] Architectural Overview Simple 2 layer architecture (user interface and data access layer) with 1 optional cache layer ASP.NET Web Form based user interface Custom Entity Data Container implemented (with primitive C# types for data fields) Active Record Design Pattern based Data Access Layer, implemented in C# and Entity Framework 4.0 Sql Server Stored Procedure to perform actual CRUD operation Standard infrastructure (architecture, helper utility) for automated integration (bottom up manner) and unit testing Technology UtilizedProgramming Languages/Scripts Browser side: JavaScript Web server side: C# 4.0 Database server side: T-SQL .NET Framework Components .NET 4.0 Entity Framework .NET 4.0 Optional/Named Parameters .NET 4.0 Tuple .NET 3.0+ Extension Method .NET 3.0+ Lambda Expressions .NET 3.0+ Aanonymous Type .NET 3.0+ Query Expressions .NET 3.0+ Automatically Implemented Properties .NET 3.0+ LINQ .NET 2.0 + Partial Classes .NET 2.0 + Generic Type .NET 2.0 + Nullable Type   ASP.NET 3.5+ List View (TBD) ASP.NET 3.5+ Data Pager (TBD) ASP.NET 2.0+ Grid View ASP.NET 2.0+ Form View ASP.NET 2.0+ Skin ASP.NET 2.0+ Theme ASP.NET 2.0+ Master Page ASP.NET 2.0+ Object Data Source ASP.NET 1.0+ Role Based Security Visual Studio Features Visual Studio 2010 CodedUI Test Visual Studio 2010 Layer Diagram Visual Studio 2010 Sequence Diagram Visual Studio 2010 Directed Graph Visual Studio 2005+ Database Unit Test Visual Studio 2005+ Unit Test Visual Studio 2005+ Web Test Visual Studio 2005+ Load Test Sql Server Features Sql Server 2005 Stored Procedure Sql Server 2005 Xml type Sql Server 2005 Paging support

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  • Employee Info Starter Kit - Visual Studio 2010 and .NET 4.0 Version (4.0.0) Available

    - by Mohammad Ashraful Alam
    Employee Info Starter Kit is a ASP.NET based web application, which includes very simple user requirements, where we can create, read, update and delete (crud) the employee info of a company. Based on just a database table, it explores and solves most of the major problems in web development architectural space.  This open source starter kit extensively uses major features available in latest Visual Studio, ASP.NET and Sql Server to make robust, scalable, secured and maintanable web applications quickly and easily. Since it's first release, this starter kit achieved a huge popularity in web developer community and includes 1,40,000+ download from project web site. Visual Studio 2010 and .NET 4.0 came up with lots of exciting features to make software developers life easier.  A new version (v4.0.0) of Employee Info Starter Kit is now available in both MSDN Code Gallery and CodePlex. Chckout the latest version of this starter kit to enjoy cool features available in Visual Studio 2010 and .NET 4.0. [ Release Notes ] Architectural Overview Simple 2 layer architecture (user interface and data access layer) with 1 optional cache layer ASP.NET Web Form based user interface Custom Entity Data Container implemented (with primitive C# types for data fields) Active Record Design Pattern based Data Access Layer, implemented in C# and Entity Framework 4.0 Sql Server Stored Procedure to perform actual CRUD operation Standard infrastructure (architecture, helper utility) for automated integration (bottom up manner) and unit testing Technology UtilizedProgramming Languages/Scripts Browser side: JavaScript Web server side: C# 4.0 Database server side: T-SQL .NET Framework Components .NET 4.0 Entity Framework .NET 4.0 Optional/Named Parameters .NET 4.0 Tuple .NET 3.0+ Extension Method .NET 3.0+ Lambda Expressions .NET 3.0+ Aanonymous Type .NET 3.0+ Query Expressions .NET 3.0+ Automatically Implemented Properties .NET 3.0+ LINQ .NET 2.0 + Partial Classes .NET 2.0 + Generic Type .NET 2.0 + Nullable Type   ASP.NET 3.5+ List View (TBD) ASP.NET 3.5+ Data Pager (TBD) ASP.NET 2.0+ Grid View ASP.NET 2.0+ Form View ASP.NET 2.0+ Skin ASP.NET 2.0+ Theme ASP.NET 2.0+ Master Page ASP.NET 2.0+ Object Data Source ASP.NET 1.0+ Role Based Security Visual Studio Features Visual Studio 2010 CodedUI Test Visual Studio 2010 Layer Diagram Visual Studio 2010 Sequence Diagram Visual Studio 2010 Directed Graph Visual Studio 2005+ Database Unit Test Visual Studio 2005+ Unit Test Visual Studio 2005+ Web Test Visual Studio 2005+ Load Test Sql Server Features Sql Server 2005 Stored Procedure Sql Server 2005 Xml type Sql Server 2005 Paging support

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  • WinRT WebView and Cookies

    - by javarg
    Turns out that WebView Control in WinRT is much more limited than it’s counterpart in WPF/Silverlight. There are some great articles out there in how to extend the control in order for it to support navigation events and some other features. For a personal project I'm working on, I needed to grab cookies a Web Site generated for the user. Basically, after a user authenticated to a Web Site I needed to get the authentication cookies and generate some extra requests on her behalf. In order to do so, I’ve found this great article about a similar case using SharePoint and Azure ACS. The secret is to use a p/invoke to native InternetGetCookieEx to get cookies for the current URL displayed in the WebView control.   void WebView_LoadCompleted(object sender, NavigationEventArgs e) { var urlPattern = "http://someserver.com/somefolder"; if (e.Uri.ToString().StartsWith(urlPattern)) { var cookies = InternetGetCookieEx(e.Uri.ToString()); // Do something with the cookies } } static string InternetGetCookieEx(string url) { uint sizeInBytes = 0; // Gets capacity length first InternetGetCookieEx(url, null, null, ref sizeInBytes, INTERNET_COOKIE_HTTPONLY, IntPtr.Zero); uint bufferCapacityInChars = (uint)Encoding.Unicode.GetMaxCharCount((int)sizeInBytes); // Now get cookie data var cookieData = new StringBuilder((int)bufferCapacityInChars); InternetGetCookieEx(url, null, cookieData, ref bufferCapacityInChars, INTERNET_COOKIE_HTTPONLY, IntPtr.Zero); return cookieData.ToString(); }   Function import using p/invoke follows: const int INTERNET_COOKIE_HTTPONLY = 0x00002000; [DllImport("wininet.dll", CharSet = CharSet.Unicode, SetLastError = true)] static extern bool InternetGetCookieEx(string pchURL, string pchCookieName, StringBuilder pchCookieData, ref System.UInt32 pcchCookieData, int dwFlags, IntPtr lpReserved); Enjoy!

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  • Mauritius Software Craftsmanship Community

    There we go! I finally managed to push myself forward and pick up an old, actually too old, idea since I ever arrived here in Mauritius more than six years ago. I'm talking about a community for all kind of ICT connected people. In the past (back in Germany), I used to be involved in various community activities. For example, I was part of the Microsoft Community Leader/Influencer Program (CLIP) in Germany due to an FAQ on Visual FoxPro, actually Active FoxPro Pages (AFP) to be more precise. Then in 2003/2004 I addressed the responsible person of the dFPUG user group in Speyer in order to assist him in organising monthly user group meetings. Well, he handed over management completely, and attended our meetings regularly. Why did it take you so long? Well, I don't want to bother you with the details but short version is that I was too busy on either job (building up new companies) or private life (got married and we have two lovely children, eh 'monsters') or even both. But now is the time where I was starting to look for new fields given the fact that I gained some spare time. My businesses are up and running, the kids are in school, and I am finally in a position where I can commit myself again to community activities. And I love to do that! Why a new user group? Good question... And 'easy' to answer. Since back in 2007 I did my usual research, eh Google searches, to see whether there existing user groups in Mauritius and in which field of interest. And yes, there are! If I recall this correctly, then there are communities for PHP, Drupal, Python (just recently), Oracle, and Linux (which used to be even two). But... either they do not exist anymore, they are dormant, or there is only a low heart-beat, frankly speaking. And yes, I went to meetings of the Linux User Group Meta (Mauritius) back in 2010/2011 and just recently. I really like the setup and the way the LUGM is organised. It's just that I have a slightly different point of view on how a user group or community should organise itself and how to approach future members. Don't get me wrong, I'm not criticizing others doing a very good job, I'm only saying that I'd like to do it differently. The last meeting of the LUGM was awesome; read my feedback about it. Ok, so what's up with 'Mauritius Software Craftsmanship Community' or short: MSCC? As I've already written in my article on 'Communities - The importance of exchange and discussion' I think it is essential in a world of IT to stay 'connected' with a good number of other people in the same field. There is so much dynamic and every day's news that it is almost impossible to keep on track with all of them. The MSCC is going to provide a common platform to exchange experience and share knowledge between each other. You might be a newbie and want to know what to expect working as a software developer, or as a database administrator, or maybe as an IT systems administrator, or you're an experienced geek that loves to share your ideas or solutions that you implemented to solve a specific problem, or you're the business (or HR) guy that is looking for 'fresh' blood to enforce your existing team. Or... you're just interested and you'd like to communicate with like-minded people. Meetup of 26.06.2013 @ L'arabica: Of course there are laptops around. Free WiFi, power outlet, coffee, code and Linux in one go. The MSCC is technology-agnostic and spans an umbrella over any kind of technology. Simply because you can't ignore other technologies anymore in a connected IT world as we have. A front-end developer for iOS applications should have the chance to connect with a Python back-end coder and eventually with a DBA for MySQL or PostgreSQL and exchange their experience. Furthermore, I'm a huge fan of cross-platform development, and it is very pleasant to have pure Web developers - with all that HTML5, CSS3, JavaScript and JS libraries stuff - and passionate C# or Java coders at the same table. This diversity of knowledge can assist and boost your personal situation. And last but not least, there are projects and open positions 'flying' around... People might like to hear others opinion about an employer or get new impulses on how to tackle down an issue at their workspace, etc. This is about community. And that's how I see the MSCC in general - free of any limitations be it by programming language or technology. Having the chance to exchange experience and to discuss certain aspects of technology saves you time and money, and it's a pleasure to enjoy. Compared to dusty books and remote online resources. It's human! Organising meetups (meetings, get-together, gatherings - you name it!) As of writing this article, the MSCC is currently meeting every Wednesday for the weekly 'Code & Coffee' session at various locations (suggestions are welcome!) in Mauritius. This might change in the future eventually but especially at the beginning I think it is very important to create awareness in the Mauritian IT world. Yes, we are here! Come and join us! ;-) The MSCC's main online presence is located at Meetup.com because it allows me to handle the organisation of events and meeting appointments very easily, and any member can have a look who else is involved so that an exchange of contacts is given at any time. In combination with the other entities (G+ Communities, FB Pages or in Groups) I advertise and manage all future activities here: Mauritius Software Craftsmanship Community This is a community for those who care and are proud of what they do. For those developers, regardless how experienced they are, who want to improve and master their craft. This is a community for those who believe that being average is just not good enough. I know, there are not many 'craftsmen' yet but it's a start... Let's see how it looks like by the end of the year. There are free smartphone apps for Android and iOS from Meetup.com that allow you to keep track of meetings and to stay informed on latest updates. And last but not least, there is a Trello workspace to collect and share ideas and provide downloads of slides, etc. Trello is also available as free smartphone app. Sharing is caring! As mentioned, the #MSCC is present in various social media networks in order to cover as many people as possible here in Mauritius. Following is an overview of the current networks: Twitter - Latest updates and quickies Google+ - Community channel Facebook - Community Page LinkedIn - Community Group Trello - Collaboration workspace to share and develop ideas Hopefully, this covers the majority of computer-related people in Mauritius. Please spread the word about the #MSCC between your colleagues, your friends and other interested 'geeks'. Your future looks bright Running and participating in a user group or any kind of community usually provides quite a number of advantages for anyone. On the one side it is very joyful for me to organise appointments and get in touch with people that might be interested to present a little demo of their projects or their recent problems they had to tackle down, and on the other side there are lots of companies that have various support programs or sponsorships especially tailored for user groups. At the moment, I already have a couple of gimmicks that I would like to hand out in small contests or raffles during one of the upcoming meetings, and as said, companies provide all kind of goodies, books free of charge, or sometimes even licenses for communities. Meeting other software developers or IT guys also opens up your point of view on the local market and there might be interesting projects or job offers available, too. A community like the Mauritius Software Craftsmanship Community is great for freelancers, self-employed, students and of course employees. Meetings will be organised on a regular basis, and I'm open to all kind of suggestions from you. Please leave a comment here in blog or join the conversations in the above mentioned social networks. Let's get this community up and running, my fellow Mauritians! Recent updates The MSCC is now officially participating in the O'Reilly UK User Group programm and we are allowed to request review or recension copies of recent titles. Additionally, we have a discount code for any books or ebooks that you might like to order on shop.oreilly.com. More applications for user group sponsorship programms are pending and I'm looking forward to a couple of announcement very soon. And... we need some kind of 'corporate identity' - Over at the MSCC website there is a call for action (or better said a contest with prizes) to create a unique design for the MSCC. This would include a decent colour palette, a logo, graphical banners for Meetup, Google+, Facebook, LinkedIn, etc. and of course badges for our craftsmen to add to their personal blogs and websites. Please spread the word and contribute. Thanks!

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  • Enum.HasFlag method in C# 4.0

    - by Jalpesh P. Vadgama
    Enums in dot net programming is a great facility and we all used it to increase code readability. In earlier version of .NET framework we don’t have any method anything that will check whether a value is assigned to it or not. In C# 4.0 we have new static method called HasFlag which will check that particular value is assigned or not. Let’s take an example for that. First I have created a enum called PaymentType which could have two values Credit Card or Debit Card. Just like following. public enum PaymentType { DebitCard=1, CreditCard=2 } Now We are going to assigned one of the value to this enum instance and then with the help of HasFlag method we are going to check whether particular value is assigned to enum or not like following. protected void Page_Load(object sender, EventArgs e) { PaymentType paymentType = PaymentType.CreditCard; if (paymentType.HasFlag(PaymentType.DebitCard)) { Response.Write("Process Debit Card"); } if (paymentType.HasFlag(PaymentType.CreditCard)) { Response.Write("Process Credit Card"); } } Now Let’s check out in browser as following. As expected it will print process Credit Card as we have assigned that value to enum. That’s it It’s so simple and cool. Stay tuned for more.. Happy Programming.. Technorati Tags: Enum,C#4.0,ASP.NET 4.0

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  • The C++ Standard Template Library as a BDB Database (part 1)

    - by Gregory Burd
    If you've used C++ you undoubtedly have used the Standard Template Libraries. Designed for in-memory management of data and collections of data this is a core aspect of all C++ programs. Berkeley DB is a database library with a variety of APIs designed to ease development, one of those APIs extends and makes use of the STL for persistent, transactional data storage. dbstl is an STL standard compatible API for Berkeley DB. You can make use of Berkeley DB via this API as if you are using C++ STL classes, and still make full use of Berkeley DB features. Being an STL library backed by a database, there are some important and useful features that dbstl can provide, while the C++ STL library can't. The following are a few typical use cases to use the dbstl extensions to the C++ STL for data storage. When data exceeds available physical memory.Berkeley DB dbstl can vastly improve performance when managing a dataset which is larger than available memory. Performance suffers when the data can't reside in memory because the OS is forced to use virtual memory and swap pages of memory to disk. Switching to BDB's dbstl improves performance while allowing you to keep using STL containers. When you need concurrent access to C++ STL containers.Few existing C++ STL implementations support concurrent access (create/read/update/delete) within a container, at best you'll find support for accessing different containers of the same type concurrently. With the Berkeley DB dbstl implementation you can concurrently access your data from multiple threads or processes with confidence in the outcome. When your objects are your database.You want to have object persistence in your application, and store objects in a database, and use the objects across different runs of your application without having to translate them to/from SQL. The dbstl is capable of storing complicated objects, even those not located on a continous chunk of memory space, directly to disk without any unnecessary overhead. These are a few reasons why you should consider using Berkeley DB's C++ STL support for your embedded database application. In the next few blog posts I'll show you a few examples of this approach, it's easy to use and easy to learn.

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  • How do I run Firefox OS as a standalone application?

    - by JamesTheAwesomeDude
    I got the add-on for the Firefox OS simulator, and it works great! It even keeps functioning after Firefox is closed, so I can save processing power for other things. I'd like to run it as a standalone application, so that I don't even have to open Firefox in the first place. I've gone to the System Monitor, and it says that the process (I guessed which by CPU usage and filename) was started via /home/james/.mozilla/firefox-trunk/vkuuxfit.default/extensions/[email protected]/resources/r2d2b2g/data/linux64/b2g/plugin-container 3386 true tab, so I tried running that in the Terminal (after I'd closed the simulator, of course,) but it gives this: james@james-OptiPlex-GX620:~/.mozilla/firefox-trunk/vkuuxfit.default/extensions/[email protected]/resources/r2d2b2g/data/linux64/b2g$ ./plugin-container 3386 true tab ./plugin-container: error while loading shared libraries: libxpcom.so: cannot open shared object file: No such file or directory james@james-OptiPlex-GX620:~/.mozilla/firefox-trunk/vkuuxfit.default/extensions/[email protected]/resources/r2d2b2g/data/linux64/b2g$ What should I do? Is what I'm attempting even possible? (It should be, since the simulator kept running even after Firefox itself was closed...) NOTE: I've tried chmod u+sx plugin-container, but that didn't help.

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  • Parsing HTML Documents with the Html Agility Pack

    Screen scraping is the process of programmatically accessing and processing information from an external website. For example, a price comparison website might screen scrape a variety of online retailers to build a database of products and what various retailers are selling them for. Typically, screen scraping is performed by mimicking the behavior of a browser - namely, by making an HTTP request from code and then parsing and analyzing the returned HTML. The .NET Framework offers a variety of classes for accessing data from a remote website, namely the WebClient class and the HttpWebRequest class. These classes are useful for making an HTTP request to a remote website and pulling down the markup from a particular URL, but they offer no assistance in parsing the returned HTML. Instead, developers commonly rely on string parsing methods like String.IndexOf, String.Substring, and the like, or through the use of regular expressions. Another option for parsing HTML documents is to use the Html Agility Pack, a free, open-source library designed to simplify reading from and writing to HTML documents. The Html Agility Pack constructs a Document Object Model (DOM) view of the HTML document being parsed. With a few lines of code, developers can walk through the DOM, moving from a node to its children, or vice versa. Also, the Html Agility Pack can return specific nodes in the DOM through the use of XPath expressions. (The Html Agility Pack also includes a class for downloading an HTML document from a remote website; this means you can both download and parse an external web page using the Html Agility Pack.) This article shows how to get started using the Html Agility Pack and includes a number of real-world examples that illustrate this library's utility. A complete, working demo is available for download at the end of this article. Read on to learn more! Read More >

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