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• Refactoring an ASP.NET 2.0 app to be more "modern"

  - by Wayne M

  This is a hypothetical scenario. Let's say you've just been hired at a company with a small development team. The company uses an internal CRM/ERP type system written in .NET 2.0 to manage all of it's day to day things (let's simplify and say customer accounts and records). The app was written a couple of years ago when .NET 2.0 was just out and uses the following architectural designs: Webforms Data layer is a thin wrapper around SqlCommand that calls stored procedures Rudimentary DTO-style business objects that are populated via the sprocs A "business logic" layer that acts as a gateway between the webform and database (i.e. code behind calls that layer) Let's say that as there are more changes and requirements added to the application, you start to feel that the old architecture is showing its age, and changes are increasingly more difficult to make. How would you go about introducing refactoring steps to A) Modernize the app (i.e. proper separation of concerns) and B) Make sure that the app can readily adapt to change in the organization? IMO the changes would involve: Introduce an ORM like Linq to Sql and get rid of the sprocs for CRUD Assuming that you can't just throw out Webforms, introduce the M-V-P pattern to the forms Make sure the gateway classes conform to SRP and the other SOLID principles. Change the logic that is re-used to be web service methods instead of having to reuse code What are your thoughts? Again this is a totally hypothetical scenario that many of us have faced in the past, or may end up facing.

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• Concerned with footerrow in gridview

  - by ramyatk06

  hi guys, I have following gridview. <asp:GridView ID="gvMarks" runat="server" AutoGenerateColumns="false" DataKeyNames="MarkId" Width="80%" onrowdatabound="gvMarks_RowDataBound" ShowFooter="True" onrowcommand="gvMarks_RowCommand"> <Columns> <asp:TemplateField> <HeaderTemplate> SubjectCode </HeaderTemplate> <FooterTemplate> <asp:DropDownList ID="dlSubjectCode" runat="server" width="100px" AutoPostBack="false"></asp:DropDownList> </FooterTemplate> </asp:TemplateField> <asp:TemplateField> <HeaderTemplate> Mark </HeaderTemplate> <FooterTemplate> <asp:TextBox ID="txtInternalMark" runat="server" ></asp:TextBox> </FooterTemplate> </asp:TemplateField> <asp:TemplateField> <HeaderTemplate> Insert </HeaderTemplate> <FooterTemplate> <asp:LinkButton ID="lnkInsert" runat="server" Text="Insert" CommandName="Insert" ></asp:LinkButton> </FooterTemplate> </asp:TemplateField> </Columns> <FooterStyle BackColor="White" ForeColor="#000066" /> <RowStyle ForeColor="#000066" /> <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" /> <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" /> <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" /> </asp:GridView> If i enter some value in txtInternalMark,iam not geting its value in code behind.Iam geting the value as "".Iam using following code if (e.CommandName.Equals("Insert")) { TextBox txtInternalMark = (TextBox)gvMarks.FooterRow.FindControl("txtInternalMark"); lblMessage.Text = txtInternalMark .Text; } Can anybody help to get the value of textbox in codebehind.

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• Modify Gridview as it's being rendered through javascript

  - by JonF

  I'm trying to modify a field in each row of my gridview as it is rendered. I need to modify it with client side Javascript. I'm somewhat new to asp.net, but I think I should be doing something with clientscriptmanager. I came up with a simple scenario which is basically what I want to do to avoid getting bogged down in the details. If I could accomplish the following I could accomplish my goal. Say I have a grid view of names and salaries. I want to double each persons salary before displaying it. Obviously I can do it in the code behind, but due to the nature of the more complex actual thing I'm doing, I need to do it in javascript <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" onrowdatabound="GridView1_RowDataBound" > <Columns> <asp:BoundField HeaderText="Full Name" DataField="Name" ></asp:BoundField> <asp:BoundField HeaderText="Salary" DataField="Salary" /> </Columns>

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• WPF ObservableCollection in xaml

  - by Cloverness

  Hi, I have created an ObservableCollection in the code behind of a user control. It is created when the window loads: private void UserControl_Loaded(object sender, RoutedEventArgs e) { Entities db = new Entities(); ObservableCollection<Image> _imageCollection = new ObservableCollection<Image>(); IEnumerable<library> libraryQuery = from c in db.ElectricalLibraries select c; foreach (ElectricalLibrary c in libraryQuery) { Image finalImage = new Image(); finalImage.Width = 80; BitmapImage logo = new BitmapImage(); logo.BeginInit(); logo.UriSource = new Uri(c.url); logo.EndInit(); finalImage.Source = logo; _imageCollection.Add(finalImage); } } I need to get the ObservableCollection of images which are created based on the url saved in a database. But I need a ListView or other ItemsControl to bind to it in XAML file like this: But I can't figure it out how to pass the ObservableCollection to the ItemsSource of that control. I tried to create a class and then create an instance of a class in xaml file but it did not work. Should I create a static resource somehow Any help will be greatly appreciated.

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• VS ASP.NET 500 Server Error

  - by rlb.usa

  Hey guys, I'm having a super weird problem with my VS 2008 solution. We had this hand-coded ASP.NET compiled web app on our old IIS6/Win2003 server, working great, moved it to our new IIS7/Win2008 server, still working great, but when I try to compile the application and publish it again to our new Win2008 server, I get server 500 errors. It's ASP.NET 2.0 with AJAX extensions and AJAX control toolkit. I'm not too great with server issues, or even sure if it is a server issue but here are some more symptoms... ? I know the website works (it only differs by some minor code fixes) and can use it's code on a development machine, there are no errors, and it publishes fine. Publishing (using the DLL files), and even not publishing and trying to use the code-behind files on our new server, both no success. The old website does work on the new server just fine. If I put a simple hello world html page in the website's virtual directory, with the old code, it works fine, but with the new code, that html page gets the 500 error. And in fact, oddly, I can add all the files to the website, only when I add the web.config, do I get the 500 error. The web.config has not changed. Tried stopping and restarting IIS What's the problem, here? Any ideas, what else can I do to troubleshoot the problem?

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• Asp.Net 2 integrated sites How to Logout second site programatically.

  - by NBrowne

  Hi , I am working with an asp.net 2.0 site (call it site 1) which has an iframe in it which loads up another site (site2) which is also an asp.net site which is developed by our team. When you log onto site 1 then behind the scenes site 2 is also logged in so that when you click the iframe tab then this displays site 2 with the user logged in (to prevent the user from having to log in twice). The problem i have is that when a user logs out of site 1 then we call some cleanup methods to perform FormsAuthentication.SignOut and clean session variables etc but at the moment no cleanup is called when the user on site 2. So the issue is that if the user opens up Site 2 from within a browser then website 2 opens with the user still logged in which is undesired. Can anyone give me some guidance as to the best approach for this?? One possible approach i though of was just that on click of logout button i could do a call to a custom page on Site 2 which would do the logout. Code below HttpWebRequest request; request = ((HttpWebRequest)(WebRequest.Create("www.mywebsite.com/Site2Logout.aspx"))); request.Method = "POST"; HttpCookie cookie = HttpContext.Current.Request.Cookies[FormsAuthentication.FormsCookieName]; Cookie authenticationCookie = new Cookie( FormsAuthentication.FormsCookieName, cookie.Value, cookie.Path, HttpContext.Current.Request.Url.Authority); request .CookieContainer = new CookieContainer(); request .CookieContainer.Add(authenticationCookie); response.GetResponse(); Problem i am having with this code is that when i run it and debug on Site 2 and check to see if the user is Authenticated they are not which i dont understand because if i open browser and browse to Site 2 i am Still authenticated. Any ideas , different direction to take etc ??? Please let me know if you need any more info or if i something i have said dosent make sense. Thanks

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• Am I fundamentally misunderstanding how Silverlight runs? (debugging issues)

  - by SP

  I've got a vs2010 solution containing an ASP.Net 4 website, and a Silverlight 4 project. The website is linked to the Silverlight project ('Map') and the ClientBin folder contains a Map.xap file. The Map project is very simple. It contains the default App.xaml and App.xaml.cs files. The MainPage.xaml file looks like this <UserControl x:Class="Map.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="380" d:DesignWidth="800"> <Canvas x:Name="MainCanvas" Width="800" Height="380"> <Canvas.Background> <ImageBrush ImageSource="map.png" Stretch="None"/> </Canvas.Background> </Canvas> The code behind for that looks like this: public partial class MainPage : UserControl { public MainPage() { InitializeComponent(); throw new Exception(); } } Inside one of the website pages I have the default object pointing to my Silverlight xap When I run the website, I see my background image on the Canvas in the Silverlight window, so I know it's working in that sense. However, I cannot break on any breakpoints set in the MainPage.xaml.cs file (in IE). I have checked the correct settings for Silverlight debugging. And see that Exception I'm throwing in the MainPage constructor? I'm not seeing that either. In fact, nothing I put in there seems to be run at all, but I know the xaml is rendering because I can see my canvas background. What am I not getting here?

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• how can access public properties of MasterPage from external Class ?

  - by eugeneK

  Why i can't access MasterPage's public property (MessagePlaceholder) from other Class (Errors) ? Error compiler gives me is "Error 1 The type or namespace name 'MyMasterPage' could not be found (are you missing a using directive or an assembly reference?)" my master page code behind using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class MyMasterPage : System.Web.UI.MasterPage { public string MessagePlaceholder { get { return messagePlaceholder.InnerHtml; } set { messagePlaceholder.InnerHtml = value; } } protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { messagePlaceholder.InnerHtml = Errors.getMessage(); } } } my Errors Class public static string getMessage() { HttpContext c = HttpContext.Current; string messageType = ""; if (c.Session["errorMessage"] != null) { messageType = "errorMessage"; } else if (c.Session["successMessage"] != null) { messageType = "successMessage"; } if (!string.IsNullOrEmpty(messageType)) { StringBuilder userMessageSb = new StringBuilder(); userMessageSb.Append(string.Format("<div id=\"{0}\" title=\"{1}\">{2}</div>", messageType, messageType.Replace("Message",string.Empty), c.Session[messageType])); // fix so message will not re-appear c.Session.Remove(messageType); messageType = userMessageSb.ToString(); } return messageType; } public static void setSuccess(string successMessage, bool isRedirect) { HttpContext.Current.Session["successMessage"] = successMessage; } public static void setError(string errorMessage, bool isRedirect) { HttpContext.Current.Session["errorMessage"] = errorMessage; if (!isRedirect) { ((HttpContext.Current.CurrentHandler as System.Web.UI.Page).Master as MyMasterPage).MessagePlaceholder = getMessage(); } } this is how i set error if (true) { Errors.setError("this is an error demo", false); return; } or with redirect after error if (true) { Errors.setError("yet another error", true); Response.Redirect("~/error.aspx"); }

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• Binding between Usercontrol with listbox and parent control (MVVM)

  - by walkor

  I have a UserControl which contains a listbox and few buttons. <UserControl x:Class="ItemControls.ListBoxControl" 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"> <Grid> <ListBox:ExtendedListBox SelectionMode="Single" ItemsSource="{Binding LBItems}" Height="184"> <ListBox.ItemTemplate> <DataTemplate> <CheckBox Content="{Binding}"/> </DataTemplate> </ListBox.ItemTemplate> </ListBox> <Button Command="RemoveCommand"/> </Grid> </UserControl> And the code behind: public static readonly DependencyProperty RemoveCommandProperty = DependencyProperty.Register("RemoveCommand", typeof(ICommand), typeof(ListBoxControl), null); public ICommand RemoveCommand { get { return (ICommand)GetValue(RemoveCommandProperty); } set { SetValue(RemoveCommandProperty, value); } } public static readonly DependencyProperty LBItemsProperty = DependencyProperty.Register("LBItems", typeof(IEnumerable), typeof(ListBoxControl), null); public IEnumerable LBItems { get { return (IEnumerable)GetValue(LBItemsProperty); } set { SetValue(LBItemsProperty, value); } } I'm using this control in the view like this: <ItemControls:ListBoxControl Height="240" Width="350" LBItems="{Binding Items, Converter={StaticResource ItemsConverter}, Mode=TwoWay}" RemoveCommand="{Binding RemoveCommand}"/> The command works fine, though the listbox binding doesn't. My question is - WHY?

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• Determining selected state of jQuery Buttons

  - by lloydphillips

  I've got two radio buttons in a .net page which are being transformed to jQuery buttons a la http://jqueryui.com/demos/button/#radio When the page is loaded I have button 2 as checked. When clicking the buttons I'm firing the postback event. Problem is you can click on that button that is selected by default on the initial load i.e. Button 2, the postback is fired but the event handler isn't called in the .net code behind because the radio button is already classed as selected (and in normal circumstances wouldn't allow the postback to fire). To get around this I've added the e.PreventDefault() method BUT this is causing issues when Button 1 is clicked because before the click handler is called the button is set to selected. Therefore, in every case in the following code e.PreventDefault() is called: $(document).ready(function(){ $("[id*='rbPayable']").click(function(e){ if ($("[id*='rbPayable']").attr("checked")) e.preventDefault(); else setTimeout('__doPostBack(\'this.id\',\'\')', 0) }) $("[id*='rbReceivable']").click(function(e){ if ($("[id*='rbReceivable']").attr("checked")) e.preventDefault(); else setTimeout('__doPostBack(\'this.id\',\'\')', 0) }) }); What is the best way for me to load the page and effectively be able to do the following: 'If rbReceivable is checked then don't do anything otherwise do a postback.'

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• How to configure Server Topology for exposing an internal application for external access?

  - by ronaldwidha

  Hi All, I guess this question is bordering to a Server Fault question. I'd like to know the best configuration for exposing an internal application (in this case a load balanced Asp.Net MVC application) for external access. More details about the situation: The Asp.Net MVC Application is currently running on 2 servers The 2 servers are behind a Windows Network Load Balancer All the servers are on premise/internal network I'm thinking of introducing an F5 Load balancer on off premise DMZ to replace the Windows Network Load Balancer. F5 will act as the public traffic gateway and load balancers to the 2 servers. However, I'd like the internal users to not have go through the Internet to access the app. The idea that I have so far is to keep both Windows Network Load Balancer and the F5. Each appliance will have its own IP and will have its own domain name. External users can use the public domain name which will hit F5, whereas internal users can use the internal domain name which will hit the Windows Network Load Balancer. Is this a good idea? Or is there a better way of doing this?

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• What are the general strategies for the server of an FPS multiplayer game to update its clients?

  - by Hooray Im Helping

  A friend and I were having a discussion about how a FPS server updates the clients connected to it. We watched a video of a guy cheating in Battlefield: Bad Company 2 and saw how it highlighted the position of enemies on the screen and it got us thinking. His contention was that the server only updates the client with information that is immediately relevant to the client. I.e. the server won't send information about enemy players if they are too far away from the client or out of the client's line of sight for reasons of efficiency. He was unsure though - he brought up the example of someone hiding behind a rock, not able to see anyone. If the player were suddenly to pop up where he had three players in his line of sight, there would be a 50ms delay before they were rendered on his screen while the server transmitted the necessary information. My contention was the opposite: that the server sends the client all the information about every player and lets the client sort out what is allowed and what isn't. I figured it would actually be less expensive computationally for the server to just send everything to the client and let the client do the heavy lifting, so to speak. I also figured this is how cheat programs work - they intercept the server packets, get the location of enemies, then show them on the client's view. So the question: What are some general policies or strategies a modern first person shooter server employs to keep its clients updated?

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• What Test Environment Setup do Top Project Committers Use in the Ruby Community?

  - by viatropos

  Today I am going to get as far as I can setting up my testing environment and workflow. I'm looking for practical advice on how to setup the test environment from you guys who are very passionate and versed in Ruby Testing. By the end of the day (6am PST?) I would like to be able to: Type one 1-command to run test suites for ANY project I find on Github. Run autotest for ANY Github project so I can fork and make TESTABLE contributions. Build gems from the ground up with Autotest and Shoulda. For one reason or another, I hardly ever run tests for projects I clone from Github. The major reason is because unless they're using RSpec and have a Rake task to run the tests, I don't see the common pattern behind it all. I have built 3 or 4 gems writing tests with RSpec, and while I find the DSL fun, it's less than ideal because it just adds another layer/language of methods I have to learn and remember. So I'm going with Shoulda. But this isn't a question about which testing framework to choose. So the questions are: What is your, the SO reader and Github project committer, test environment setup using autotest so that whenever you git clone a gem, you can run the tests and autotest-develop them if desired? What are the guys who are writing the Paperclip Tests and Authlogic Tests doing? What is their setup? Thanks for the insight. Looking for answers that will make me a more effective tester.

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• How to collect and inject all beans of a given type in Spring XML configuration

  - by GrzegorzOledzki

  One of the strongest accents of the Spring framework is the Dependency Injection concept. I understand one of the advices behind that is to separate general high-level mechanism from low-level details (as announced by Dependency Inversion Principle). Technically, that boils down to having a bean implementation to know as little as possible about a bean being injected as a dependency, e.g. public class PrintOutBean { private LogicBean logicBean; public void action() { System.out.println(logicBean.humanReadableDetails()); } //... } <bean class="PrintOutBean"> <property name="loginBean" ref="ShoppingCartBean"/> </bean> But what if I wanted to a have a high-level mechanism operating on multiple dependent beans? public class MenuManagementBean { private Collection<Option> options; public void printOut() { for (Option option:options) { // do something for option } //... } } I know one solution would be to use @Autowired annotation in the singleton bean, that is... @Autowired private Collection<Option> options; But doesn't it violate the separation principle? Why do I have to specify what dependents to take in the very same place I use them (i.e. MenuManagementBean class in my example)? Is there a way to inject collections of beans in the XML configuration like this (without any annotation in the MMB class)? <bean class="MenuManagementBean"> <property name="options"> <xxx:autowire by-type="MyOptionImpl"/> </property> </bean>

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• Connection Pool Strategy: Good, Bad or Ugly?

  - by Drew

  I'm in charge of developing and maintaining a group of Web Applications that are centered around similar data. The architecture I decided on at the time was that each application would have their own database and web-root application. Each application maintains a connection pool to its own database and a central database for shared data (logins, etc.) A co-worker has been positing that this strategy will not scale because having so many different connection pools will not be scalable and that we should refactor the database so that all of the different applications use a single central database and that any modifications that may be unique to a system will need to be reflected from that one database and then use a single pool powered by Tomcat. He has posited that there is a lot of "meta data" that goes back and forth across the network to maintain a connection pool. My understanding is that with proper tuning to use only as many connections as necessary across the different pools (low volume apps getting less connections, high volume apps getting more, etc.) that the number of pools doesn't matter compared to the number of connections or more formally that the difference in overhead required to maintain 3 pools of 10 connections is negligible compared to 1 pool of 30 connections. The reasoning behind initially breaking the systems into a one-app-one-database design was that there are likely going to be differences between the apps and that each system could make modifications on the schema as needed. Similarly, it eliminated the possibility of system data bleeding through to other apps. Unfortunately there is not strong leadership in the company to make a hard decision. Although my co-worker is backing up his worries only with vagueness, I want to make sure I understand the ramifications of multiple small databases/connections versus one large database/connection pool.

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• wxpython - Running threads sequentially without blocking GUI

  - by ryantmer

  I've got a GUI script with all my wxPython code in it, and a separate testSequences module that has a bunch of tasks that I run based on input from the GUI. The tasks take a long time to complete (from 20 seconds to 3 minutes), so I want to thread them, otherwise the GUI locks up while they're running. I also need them to run one after another, since they all use the same hardware. (My rationale behind threading is simply to prevent the GUI from locking up.) I'd like to have a "Running" message (with varying number of periods after it, i.e. "Running", "Running.", "Running..", etc.) so the user knows that progress is occurring, even though it isn't visible. I'd like this script to run the test sequences in separate threads, but sequentially, so that the second thread won't be created and run until the first is complete. Since this is kind of the opposite of the purpose of threads, I can't really find any information on how to do this... Any help would be greatly appreciated. Thanks in advance! gui.py import testSequences from threading import Thread #wxPython code for setting everything up here... for j in range(5): testThread = Thread(target=testSequences.test1) testThread.start() while testThread.isAlive(): #wait until the previous thread is complete time.sleep(0.5) i = (i+1) % 4 self.status.SetStatusText("Running"+'.'*i) testSequences.py import time def test1(): for i in range(10): print i time.sleep(1) (Obviously this isn't the actual test code, but the idea is the same.)

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• Link Button on asp.net user control not firing

  - by andyriome

  Hi I have a user control, which is added to another user control. The nested user control is built up of a gridview, an image button and a link button. The nested user control is added to the outer control as a collection object based upon the results bound to the gridview. The problem that I have is that my link button doesn't work. I click on it and the event doesn't fire. Even adding a break point was not reached. As the nested user control is added a number of times, I have set image button to have unique ids and also the link button. Whilst image button works correctly with its java script. The link button needs to fire an event in the code behind, but despite all my efforts, I can't make it work. I am adding the link button to the control dynamically. Below is the relevant code that I am using: public partial class ucCustomerDetails : System.Web.UI.UserControl { protected override void CreateChildControls( ) { base.CreateChildControls( ); string strUniqueID = lnkShowAllCust.UniqueID; strUniqueID = strUniqueID.Replace('$','_'); this.lnkShowAllCust.ID = strUniqueID; this.lnkShowAllCust.Click += new EventHandler(this.lnkShowAllCust_Click); this.Controls.Add(lnkShowAllCust); } protected override void OnInit (EventArgs e) { CreateChildControls( ); base.OnInit(e); } protected override void OnLoad(EventArgs e) { base.EnsureChildControls( ); } protected void Page_Load(object sender, EventArgs e) { if (IsPostBack) { CreateChildControls( ); } } protected void lnkShowAllCust_Click(object sender, EventArgs e) { this.OnCustShowAllClicked(new EventArgs ( )); } protected virtual void OnCustShowAllClicked(EventArgs args) { if (this.ViewAllClicked != null) { this.ViewAllClicked(this, args); } } public event EventHandler ViewAllClicked; } I have been stuggling with this problem for the last 3 days and have had no success with it, and I really do need some help. Can anyone please help me?

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• How do C++ compilers actually pass reference parameters?

  - by T.E.D.

  This question came about as a result of some mixed-langauge programming. I had a Fortran routine I wanted to call from C++ code. Fortran passes all its parameters by reference (unless you tell it otherwise). So I thought I'd be clever (bad start right there) in my C++ code and define the Fortran routine something like this: extern "C" void FORTRAN_ROUTINE (unsigned & flag); This code worked for a while but (of course right when I needed to leave) suddenly started blowing up on a return call. Clear indication of a munged call stack. Another engineer came behind me and fixed the problem, declaring that the routine had to be deinfed in C++ as extern "C" void FORTRAN_ROUTINE (unsigned * flag); I'd accept that except for two things. One is that it seems rather counter-intuitive for the compiler to not pass reference parameters by reference, and I can find no documentation anywhere that says that. The other is that he changed a whole raft of other code in there at the same time, so it theoretically could have been another change that fixed whatever the issue was. So the question is, how does C++ actually pass reference parameters? Is it perhaps free to do copy-in, copy-out for small values or something? In other words, are reference parameters utterly useless in mixed-language programming? I'd like to know so I don't make this same code-killing mistake ever again.

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• Can knowing C actually hurt the code you write in higher level languages?

  - by Jurily

  The question seems settled, beaten to death even. Smart people have said smart things on the subject. To be a really good programmer, you need to know C. Or do you? I was enlightened twice this week. The first one made me realize that my assumptions don't go further than my knowledge behind them, and given the complexity of software running on my machine, that's almost non-existent. But what really drove it home was this Slashdot comment: The end result is that I notice the many naive ways in which traditional C "bare metal" programmers assume that higher level languages are implemented. They make bad "optimization" decisions in projects they influence, because they have no idea how a compiler works or how different a good runtime system may be from the naive macro-assembler model they understand. Then it hit me: C is just one more abstraction, like all others. Even the CPU itself is only an abstraction! I've just never seen it break, because I don't have the tools to measure it. I'm confused. Has my mind been mutilated beyond recovery, like Dijkstra said about BASIC? Am I living in a constant state of premature optimization? Is there hope for me, now that I realized I know nothing about anything? Is there anything to know, even? And why is it so fascinating, that everything I've written in the last five years might have been fundamentally wrong? To sum it up: is there any value in knowing more than the API docs tell me? EDIT: Made CW. Of course this also means now you must post examples of the interpreter/runtime optimizing better than we do :)

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• Best way to track the stages of a form across different controllers - $_GET or routing

  - by chrisj

  Hi, I am in a bit of a dilemma about how best to handle the following situation. I have a long registration process on a site, where there are around 10 form sections to fill in. Some of these forms relate specifically to the user and their own personal data, while most of them relate to the user's pets - my current set up handles user specific forms in a User_Controller (e.g via methods like user/profile, user/household etc), and similarly the pet related forms are handled in a Pet_Controller (e.g pet/health). Whether or not all of these methods should be combined into a single Registration_Controller, I'm not sure - I'm open to any advice on that. Anyway, my main issue is that I want to generate a progress bar which shows how far along in the registration process each user is. As the urls in each form section can potentially be mapping to different controllers, I'm trying to find a clean way to extract which stage a person is at in the overall process. I could just use the query string to pass a stage parameter with each request, e.g user/profile?stage=1. Another way to do it potentially is to use routing - e.g the urls for each section of the form could be set up to be registration/stage/1, registration/stage/2 - then i could just map these urls to the appropriate controller/method behind the scenes. If this makes any sense at all, does anyone have any advice for me?

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• Can Haskell's monads be thought of as using and returning a hidden state parameter?

  - by AJM

  I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

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• How to Prevent PostBack Event Handler from Firing

  - by user331744

  I have a custom class (ServerSideValidator.vb) that validates user input on server side (it doesn't use any of the .NET built in validators, therefore Page.Validate() is not an option for me). I am calling the Validate() method on page.IsPostback event and the class performs without any problem My issue is, when validation fails (returns false), I want to stop the postback event handler from firing, but load the page along with all the controls and user-input values in them. If I do, Response.End(), the page comes up blank. I can programmatically instruct the page to go to the previous page (original form before postback), but it loses all user-inputs. I thought of creating a global boolean variable in the page code behind file and check the value before performing any postback method, but this approach takes away from my plan to provide all functionalities inside the class itself. The page object is being referenced to ServerSideValidator. Seems like all the postback related properties/variables I come across inside Page class are 'Readonly' and I can't assign value(s) to control/prevent postback event from firing. Any idiea on how I can accomplish this? Please let me know if you need further details

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• How do I add the go language to gitg's list of viewable sources?

  - by Hotei

  Hoping a 'git' guru will help out here. I am just beginning to "git" for the first time and have (among other things :-) ) git and gitg installed from Ubuntu 10.4 / AMD64 distribution (ie. maybe not 'latest' version but not ancient). I am trying to look at the go code I've committed via gitg and in the "tree tab" it says :Cannot display file content as text. However, the "details tab" shows the diffs of the same file just fine. I know gitg's "tree tab" is working because I can use the tree view on *.c / *.html / *.txt etc just fine. Is there a way to tweak gitg into understanding that "*.go" is just text? A little more context: Installed gitg version is 0.0.5 - ie a version behind latest - 0.0.6 - source of which I am looking thru now. I do have a working /usr/share/gtksourceview-2.0/language-specs/ go.lang. It works just fine as highlighter in gedit. It appears that gitg may require displayable files to have a mime type of "text/plain", so I added that to go.lang No joy. gitg still fails on *.go I'm relatively sure the fix is simple, just don't know where to look.

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• How to get drag working properly in silverlight when mouse is not pressed ?

  - by Mrt

  Hello, I have the following code xaml <Canvas x:Name="LayoutRoot" > <Rectangle Canvas.Left="40" Canvas.Top="40" Width="20" Height="20" Name="rec" Fill="Red" MouseLeftButtonDown="rec_MouseLeftButtonDown" MouseMove="rec_MouseMove" /> </Canvas> code behind public partial class MainPage : UserControl { public MainPage() { InitializeComponent(); } public Point LastDragPosition { get; set; } private bool isDragging; private void rec_MouseMove(object sender, MouseEventArgs e) { if(!isDragging) { return; } var position = e.GetPosition(rec as UIElement); var newPosition = new Point( Canvas.GetLeft(rec) + position.X - LastDragPosition.X, Canvas.GetTop(rec) + position.Y - LastDragPosition.Y); Canvas.SetLeft(rec, newPosition.X); Canvas.SetTop(rec, newPosition.Y); LastDragPosition = e.GetPosition(rec as UIElement); } private void rec_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { isDragging = true; LastDragPosition = e.GetPosition(sender as UIElement); rec.CaptureMouse(); } } This issue is the rectangle follows the mouse if the mouse left button is down, but I would like the rectangle to move even when the mouse left button isn't down. It works, but if you move the mouse very slowly. If you move the mouse to quickly the rectangle stops moving (is the mouse capture lost ?) Cheers,

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• C As Principal Class For Mac App

  - by CodaFi

  So, I've got a c file raring to go and be the main class behind an all-C mac-app, however, a combination of limiting factors are preventing the application from being launched. As it currently stands, the project is just a main.m and a class called AppDelegate.c, so I entered "AppDelegate" as the name of the principal class in the info.plist, and to my complete surprise, the log printed: Unable to find class: AppDelegate, exiting This would work perfectly well in iOS, because the main function accepts the name of a delegate class, and handles it automatically, but NSApplicationMain() takes no such argument. Now, I know this stems from the fact that there are no @interface/@implementation directives in C, and that's really what the OS seems to be looking for, so I wrote a simple NSApplication subclass and provided it as the Principal Class to the plist, and it launched perfectly well. My question is, how could one go about setting a c file as the principal class in a mac application and have it launch correctly? PS, don't ask what or why I'm doing this for, the foundation must be dug. For @millimoose's amusement, here be the AppDelegate.c file: #include <objc/runtime.h> #include <objc/message.h> struct AppDel { Class isa; id window; }; // This is a strong reference to the class of the AppDelegate // (same as [AppDelegate class]) Class AppDelClass; BOOL AppDel_didFinishLaunching(struct AppDel *self, SEL _cmd, void *application, void *options) { self->window = objc_msgSend(objc_getClass("NSWindow"), sel_getUid("alloc")); self->window = objc_msgSend(self->window, sel_getUid("init")); objc_msgSend(self->window, sel_getUid("makeKeyAndOrderFront:"), self); return YES; }

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