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  • Problem with date_select when using :discard option. (Rails)

    - by MikeH
    I'm using a date_select with the option :discard_year => true If a user selects a date in the date select, and then he comes back and returns the select to the prompt values of Month and Day, Rails automatically sets the select values to January 1. I know this is the intended functionality if a month is selected and a day is left blank, but that's not the case here. In my example, the user sets both the month and day back to the prompt. By Rails forcing January 1, I'm getting bad results. I've tried every parameter available in the api. :default = nil, :include_blank = true. None of those change the behavior I'm describing. I've isolated the root of the problem, which is this: Because I'm discarding the :year parameter, when the user tries to return the month and day to the prompt values, Rails doesn't see an empty prompt select. It perhaps sees a year selected with empty month and day, which it then sets to January 1. This is the case because the :discard_year parameter does in fact set a date in the database, it just removes it from the view. How can I code around this problem?

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  • Asymptotic runtime of list-to-tree function

    - by Deestan
    I have a merge function which takes time O(log n) to combine two trees into one, and a listToTree function which converts an initial list of elements to singleton trees and repeatedly calls merge on each successive pair of trees until only one tree remains. Function signatures and relevant implementations are as follows: merge :: Tree a -> Tree a -> Tree a --// O(log n) where n is size of input trees singleton :: a -> Tree a --// O(1) empty :: Tree a --// O(1) listToTree :: [a] -> Tree a --// Supposedly O(n) listToTree = listToTreeR . (map singleton) listToTreeR :: [Tree a] -> Tree a listToTreeR [] = empty listToTreeR (x:[]) = x listToTreeR xs = listToTreeR (mergePairs xs) mergePairs :: [Tree a] -> [Tree a] mergePairs [] = [] mergePairs (x:[]) = [x] mergePairs (x:y:xs) = merge x y : mergePairs xs This is a slightly simplified version of exercise 3.3 in Purely Functional Data Structures by Chris Okasaki. According to the exercise, I shall now show that listToTree takes O(n) time. Which I can't. :-( There are trivially ceil(log n) recursive calls to listToTreeR, meaning ceil(log n) calls to mergePairs. The running time of mergePairs is dependent on the length of the list, and the sizes of the trees. The length of the list is 2^h-1, and the sizes of the trees are log(n/(2^h)), where h=log n is the first recursive step, and h=1 is the last recursive step. Each call to mergePairs thus takes time (2^h-1) * log(n/(2^h)) I'm having trouble taking this analysis any further. Can anyone give me a hint in the right direction?

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  • How to use void*

    - by Rondogiannis Aristophanes
    I am imlementing a simple merge function and I have got stuck, as the compiler gives me errors that I cannot explain. Here is my merge function: void merge(void *a, int beg, int middle, int end, int (*cmp)(const void*, const void* { std::stack<void*> first; std::stack<void*> second; for(int i = beg; i < middle; i++) { first.push(a+i); } for(int i = middle; i < end; i++) { second.push(a+i); } for(int i = beg; i < end; i++) { if(first.empty()) { void *tmp = second.top(); second.pop(); a+i = tmp; } else if(second.empty()) { void *tmp = first.top(); first.pop(); a+i = tmp; } else if(cmp(first.top(), second.top())) { void *tmp = first.top(); first.pop(); a+i = tmp; } else { void *tmp = second.top(); second.pop(); a+i = tmp; } } } And here is the error: sort.h: In function `void merge(void*, int, int, int, int (*)(const void*, const void*))': sort.h:9: error: pointer of type `void *' used in arithmetic sort.h:12: error: pointer of type `void *' used in arithmetic sort.h:19: error: pointer of type `void *' used in arithmetic sort.h:19: error: non-lvalue in assignment sort.h:23: error: pointer of type `void *' used in arithmetic sort.h:23: error: non-lvalue in assignment sort.h:27: error: pointer of type `void *' used in arithmetic sort.h:27: error: non-lvalue in assignment sort.h:31: error: pointer of type `void *' used in arithmetic sort.h:31: error: non-lvalue in assignment Can anyone help me? TIA.

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  • Why are my Flex resource bundles not being loaded?

    - by Chris R
    I have an Actionscript module in the flex source folder filterModules, which is one of two additional source folders in my project (the main source folder is reports, but I'm not dealing with anything in there right now). Here's the MXML content that references the resources. ... This array is assigned to the dataProvider field of a ComboBox. It's not bound using the bindings, presumably for reasons that made sense to the original developer, and it'd be nontrivial to change the class to make that happen. I additionally have a resource property file in a folder resources/en_US and I have the source folder resources/{locale} in the project source settings. My additional compiler options are -locale en_US. The resource property file is resources/en_US/labels.properties (All paths are relative to the flash builder project root) and contains (amongst other things) these keys: metric.q3 = Overall Satisfaction metric.q5 = Personnel metric.q9a = Issue Resolution metric.q42 = Visit Duration Sat metric.q34 = Visit Duration I have written some FlexUnit tests that run in my local Flash Player that exercise these resources -- they check that every label is represented in the metrics array, for example, so I know that the resource file is loaded when run locally. However, when I copy the module .swf file over to my server, the combo box to which the array is assigned is empty. I copy the .swf like so, if it matters: rsync -rlDv --inplace -T /tmp ~/projects/flex_reports/bin-debug/rankingFilter.swf HOSTNAME:WEBROOT/flashPath/ Why is this? I am not able to debug the remote module because our surrounding site sets up a lot of context and makes some database calls to determine which module to load. I'm hoping to get some pointers on why resource bundles might not show up. I'd understand it if the array was present with wrong labels, but the array is instead completely empty, which is pretty odd.

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  • Detect TCP connection close when playing Flash video

    - by JoJo
    On the Flash client side, how do I detect when the server purposely closes the TCP connection to its video stream? I'll need to take action when this occurs - maybe attempt to restart the video or display an error message. Currently, the connection closing and the connection being slow look the same to me. The NetStream object ushers a NetStream.Play.Stop event in both cases. When the connection is slow, it usually recovers by itself within seconds. I wish to only take action when the connection is closed, not when it is slow. Here's how my general setup looks like. It's the basic NetConnection-NetStream-Video setup. this.vidConnection = new NetConnection(); this.vidConnection.addEventListener(AsyncErrorEvent.ASYNC_ERROR, this.connectionAsyncError); this.vidConnection.addEventListener(IOErrorEvent.IO_ERROR, this.connectionIoError); this.vidConnection.addEventListener(NetStatusEvent.NET_STATUS, this.connectionNetStatus); this.vidConnection.connect(null); this.vidStream = new NetStream(this.vidConnection); this.vidStream.addEventListener(AsyncErrorEvent.ASYNC_ERROR, this.streamAsyncError); this.vidStream.addEventListener(IOErrorEvent.IO_ERROR, this.streamIoError); this.vidStream.addEventListener(NetStatusEvent.NET_STATUS, this.streamNetStatus); this.vid.attachNetStream(this.vidStream); None of the error events fire when the server closes the TCP or when the connection freezes up. Only the NetStream.Play.Stop event fires. Here's a trace of what happens from initially playing the video to the TCP connection closing. connection net status = NetConnection.Connect.Success playStream(http://192.168.0.44/flv/4d29104a9aefa) NetStream.Play.Start NetStream.Buffer.Flush NetStream.Buffer.Full NetStream.Buffer.Empty checkDimensions 0 0 onMetaData NetStream.Buffer.Full NetStream.Buffer.Flush checkDimensions 960 544 NetStream.Buffer.Empty NetStream.Buffer.Flush NetStream.Play.Stop

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  • How should backbone.js handle a GET request that returns no results?

    - by Nyxynyx
    I have a number of text input elements that when its values are changed, will trigger a fetch on listingListView's collection listingCollection, which then updates listingListView with the new data via the function listingListView.refreshList as shown below. I am using PHP/Codeigniter to expose a RESTful API. Problem: Everything works fine if there are results retrieved from the fetch(). However, when the filters results in no result being returned, how should the server side and the client side handle it? Currently Chrome's javascript console displays a 404 error and in the Network tab, the XHR request is highlighted in red. All I want to do in the event of zero results returned, is to blank the listingListView and show a message like (No results returned) and not throw any errors in the javascript console. Thanks! PHP Code function listings_get() { // Get filters $price_min = $this->get('price_min'); $this->load->model('app_model'); $results = $this->app_model->get_listings($price_min); if($results) $this->response($results); else $this->response(NULL); } JS Code window.ListingListView = Backbone.View.extend({ tagName: 'table', initialize: function() { this.model.bind('reset', this.refreshList, this); this.model.bind('add', function(listing) { $(this.el).append(new ListingListItemView({ model: listing }).render().el); }, this); }, render: function() { _.each(this.model.models, function(listing) { $(this.el).append(new ListingListItemView({ model: listing }).render().el); }, this); return this; }, close: function() { $(this.el).unbind(); $(this.el).empty(); }, refreshList: function() { $(this.el).empty(); this.render(); } });

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  • Validating age field

    - by Marcelo
    Hi people, I'm trying to validate an age field in a form but I'm having some problem. First I tried to make sure that the field will not be send empty. I don't know JavaScript so I searched some scripts and adapted them to this: function isInteger (s) { var i; if (isEmpty(s)) if (isInteger.arguments.length == 1) return 0; else return (isInteger.arguments[1] == true); for (i = 0; i < s.length; i++) { var c = s.charAt(i); if (!isDigit(c)) return false; } return true; } function isEmpty(s) { return ((s == null) || (s.length == 0)) } function validate_required(field,alerttxt) { with (field) { if (value==null||value=="") { alert(alerttxt);return false; } else { return true; } } } function validate_form(thisform) { with (thisform) { if ((validate_required(age,"Age must be filled out!")==false) || isInteger(age,"Age must be and int number")==false)) {email.focus();return false;} } } //html part <form action="doador.php" onsubmit="return validate_form(this)" method="post"> It's working fine for empty fields, but if I type any letters or characters in age field, it'll be sent and saved a 0 in my database. Can anyone help me? Sorry for any mistake in English, and thanks in anvance for your help.

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  • Compiling gstreamer plugin in windows

    - by utnapistim
    Hello all, My question: What is the correct way to compile a gstreamer plugin in windows, so that it will be accepted by gstreamer (actually Songbird on top of gstreamer). My setup: I have downloaded the songbird sources following the steps described here and I have a trunk/dependencies/windows-i686-msvc8 directory within my svn sources with all the gstreamer binaries. I have created a gstreamer empty plugin skeleton following the steps detailed in the GStreamer Plugin Writer's Guide, and compiled it against the gstreamer binaries in the Songbird dependencies folder. The compilation was done with VS2010 RC1 (Visual Studio 2008 yelded the same results), using an empty DLL project with the .h and .c files generated using the GStreamer Plugin Writer's Guide. The DLL was lined with libcpmt.lib, libcmt.lib, ws2_32.lib, gobject-2.0.lib, gthread-2.0.lib, gstreamer-0.10-0.lib, glib-2.0.lib, kernel32.lib, nspr4.lib and ignoring all default libraries. I have compiled the files as both .c and .cpp with the same results. Testing: I have installed the Songbird binaries corresponding to the correct svn version, then installed Songbird Developer Tools addon and used it to create an addon for testing my gstreamer plugin. Songbird will not load the pluggin. I have also tried to load it with gst-launch.exe from the trunk/dependencies/windows-i686-msvc8/[...] directory and that generated runtime error R6034: An application has made an attempt to load the C runtime library incorrectly. Most resources I found for this problem recommended restarting or reinstalling windows :(.

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  • get html content of a page with Silverlight

    - by Yustme
    Hi, I'm trying to get the html content of a page using silverlight. Webresponse and request classes don't work in silverlight. I did some googling and I found something. This is what i tried: public partial class MainPage : UserControl { string result; WebClient client; public MainPage() { InitializeComponent(); this.result = string.Empty; this.client = new WebClient(); this.client.DownloadStringCompleted += ClientDownloadStringCompleted; } private void btn1_Click(object sender, RoutedEventArgs e) { string url = "http://www.nu.nl/feeds/rss/algemeen.rss"; this.client.DownloadStringAsync(new Uri(url, UriKind.Absolute)); if (this.result != string.Empty && this.result != null) { this.txbSummery.Text = this.result; } } private void ClientDownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) { this.result = e.Result; //handle the response. } } It gives me a runtime error after pressing the button: Microsoft JScript runtime error: Unhandled Error in Silverlight Application An exception occurred during the operation, making the result invalid. Check InnerException for exception details. at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary() at System.Net.DownloadStringCompletedEventArgs.get_Result() at JWTG.MainPage.ClientDownloadStringCompleted(Object sender, DownloadStringCompletedEventArgs e) at System.Net.WebClient.OnDownloadStringCompleted(DownloadStringCompletedEventArgs e) at System.Net.WebClient.DownloadStringOperationCompleted(Object arg) I've tried numerous things but all failed. What am i missing? Or does anyone know how i could achieve this in a different way? Thanks in advance!

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  • "Order By" in LINQ-to-SQL Causes performance issues

    - by panamack
    I've set out to write a method in my C# application which can return an ordered subset of names from a table containing about 2000 names starting at the 100th name and returning the next 20 names. I'm doing this so I can populate a WPF DataGrid in my UI and do some custom paging. I've been using LINQ to SQL but hit a snag with this long executing query so I'm examining the SQL the LINQ query is using (Query B below). Query A runs well: SELECT TOP (20) [t0].[subject_id] AS [Subject_id], [t0].[session_id] AS [Session_id], [t0].[name] AS [Name] FROM [Subjects] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP (100) [t1].[subject_id] FROM [Subjects] AS [t1] WHERE [t1].[session_id] = 1 ORDER BY [t1].[name] ) AS [t2] WHERE [t0].[subject_id] = [t2].[subject_id] ))) AND ([t0].[session_id] = 1) Query B takes 40 seconds: SELECT TOP (20) [t0].[subject_id] AS [Subject_id], [t0].[session_id] AS [Session_id], [t0].[name] AS [Name] FROM [Subjects] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP (100) [t1].[subject_id] FROM [Subjects] AS [t1] WHERE [t1].[session_id] = 1 ORDER BY [t1].[name] ) AS [t2] WHERE [t0].[subject_id] = [t2].[subject_id] ))) AND ([t0].[session_id] = 1) ORDER BY [t0].[name] When I add the ORDER BY [t0].[name] to the outer query it slows down the query. How can I improve the second query? This was my LINQ stuff Nick int sessionId = 1; int start = 100; int count = 20; // Query subjects with the shoot's session id var subjects = cldb.Subjects.Where<Subject>(s => s.Session_id == sessionId); // Filter as per params var orderedSubjects = subjects .OrderBy<Subject, string>( s => s.Col_zero ); var filteredSubjects = orderedSubjects .Skip<Subject>(start) .Take<Subject>(count);

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  • Raising event in custom control.

    - by SeSSiZ
    Hi all, I'm writing a custom textblock control thats populate hyperlinks and raises event when clicked to hyperlink. I wrote this code but I got stucked. My code is : Imports System.Text.RegularExpressions Public Class CustomTextBlock Inherits TextBlock Public Event Klik As EventHandler(Of EventArgs) Public ReadOnly InlineCollectionProperty As DependencyProperty = DependencyProperty.Register("InlineCollection", GetType(String), GetType(CustomTextBlock), New PropertyMetadata(New PropertyChangedCallback(AddressOf CustomTextBlock.InlineChanged))) Private Shared Sub InlineChanged(ByVal sender As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs) DirectCast(sender, CustomTextBlock).Inlines.Clear() Dim kelimeler = Split(e.NewValue, " ") For i = 0 To kelimeler.Length - 1 If Regex.Match(kelimeler(i), "(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&amp;:/~\+#]*[\w\-\@?^=%&amp;/~\+#])?").Success Then Dim x = New Hyperlink(New Run(kelimeler(i))) x.AddHandler(Hyperlink.ClickEvent, New RoutedEventHandler(AddressOf t_Click)) x.ToolTip = kelimeler(i) x.Tag = kelimeler(i) DirectCast(sender, CustomTextBlock).Inlines.Add(x) If Not i = kelimeler.Length Then DirectCast(sender, CustomTextBlock).Inlines.Add(" ") Else DirectCast(sender, CustomTextBlock).Inlines.Add(kelimeler(i)) If Not i = kelimeler.Length Then DirectCast(sender, CustomTextBlock).Inlines.Add(" ") End If ''//Console.WriteLine(kelime(i).ToString.StartsWith("@")) Next kelimeler = Nothing End Sub Public Property InlineCollection As String Get Return DirectCast(GetValue(InlineCollectionProperty), String) End Get Set(ByVal value As String) SetValue(InlineCollectionProperty, value) End Set End Property Private Shared Sub t_Click(ByVal sender As Hyperlink, ByVal e As System.Windows.RoutedEventArgs) e.Handled = True RaiseEvent Klik(sender, EventArgs.Empty) End Sub End Class This code gives error at RaiseEvent Klik(sender, EventArgs.Empty) Error is : Cannot refer to an instance member of a class from within a shared method or shared member initializer without an expliticit instance of the class. Thanks for your answers, Alper

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  • Help a Beginner with a PHP based Login System

    - by Brian Lang
    I'm a bit embarrassed to say, but I've run into issue with creating a PHP based login system. I'm using a site template to handle the looks of the the login process, so I will spare you the code. Here is my thought process on how to handle the login: Create a simple login.php file. On there will be a form whose action is set to itself. It will check to see if the submit has been clicked, and if so validate to make sure the user entered a valid password / username. If they do, set a session variable save some login info (username, NOT password), and redirect them to a restricted area. If the login info isn't valid, save an error message in a session variable, display error message giving further instruction, and wait for the user to resubmit. Here is a chunk of what I have - hopefully one of you experts can see where I've gone wrong, and give me some insight: if(isset($_POST['submit'])) { if(!empty($_POST['username']) AND !empty(!$_POST['password'])) { header("Location: http://www.google.com"); } else { $err = 'All the fields must be filled in!'; } } if($err) { $_SESSION['msg']['login-err'] = $err; } ? Now the above is just an example - the intent of the above code is to process user input, with the script validating simply that the user has given input for username and password. If they have, I would like them, in this case, to be redirected to google.com (for the sake of this example). If not, save an error message. Given my current code, the error message will display perfectly, however if the user submits and has something entered for the username and password, the page simply doesn't redirect. I'm sure this is a silly question, but I am a beginner, and well, to be honest, a bit buzzed right now. Thanks so much!

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  • backbone.js removing template from DOM upon success

    - by timpone
    I'm writing a simple message board app to learn backbone. It's going ok (a lot of the use of this isn't making sense) but am a little stuck in terms of how I would remove a form / html from the dom. I have included most of the code but you can see about 4 lines up from the bottom, the part that isn't working. How would I remove this from the DOM? thx in advance var MbForm=Backbone.View.extend({ events: { 'click button.add-new-post': 'savePost' }, el: $('#detail'), template:_.template($('#post-add-edit-tmpl').html()), render: function(){ var compiled_template = this.template(); this.$el.html(compiled_template); return this; }, savePost: function(e){ //var self=this; //console.log("I want you to say Hello!"); data={ header: $('#post_header').val(), detail: $('#post_detail').val(), forum_id: $('#forum_id').val(), post_id: $('#post_id').val(), parent_id: $('#parent_id').val() }; this.model.save(data, { success: function(){ alert('this saved'); //$(this.el).html('this is what i want'); this.$el.remove();// <- this is the part that isn't working /* none of these worked - error Uncaught TypeError: Cannot call method 'unbind' of undefined this.$el.unbind(); this.$el.empty(); this.el.unbind(); this.el.empty(); */ //this.unbind(); //self.append('this is appended'); } });

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  • Cascading DropDown List in MVC 4

    - by Misi
    I have a ASP.NET MVC 4 project with EF I have a table with Parteners. This table has 2 types of parteners : agents(part_type=1) and clients(part_type=2). In an Create view I have the first DropDownList that shows all my agents, a button and the second DDL that shows all my clients that correspond to the selected agent. Q1 : What button shoud I use ? , , @Html.ActionLink() ? Create.cshtml <div class="editor-field"> @Html.DropDownList("idagenti", ViewData["idagenti"] as List<SelectListItem>, String.Empty) </div> @*a button*@ <div class="editor-label"> @Html.LabelFor(model => model.id_parten, "Client") </div> <div class="editor-field"> @Html.DropDownList("id_parten", String.Empty) @Html.ValidationMessageFor(model => model.id_parten) </div> OrdersController.cs public ActionResult Create(int? id) // id is the selected agent { var agqry = db.partener.Where(p => p.part_type == 1).Where(p => p.activ == true); var cltqry = db.partener.Where(p => p.part_type == 2).Where(p => p.activ == true); List<SelectListItem> idagenti = new List<SelectListItem>(); foreach (partener ag in agqry) { idagenti.Add(new SelectListItem { Text = ag.den_parten, Value = ag.id_parten.ToString() }); } if (id != null) { cltqry = cltqry.Where(p => p.par_parten == id); } ViewData["idagenti"] = idagenti; ViewBag.id_parten = new SelectList(cltqry, "id_parten", "den_parten");// } Q: How can I pass the selected agent id from the first DDL to my controller ?

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  • NHibernate mapping for subclasses and joined-subclasses

    - by Husain
    In a project that I am working on, I have the following entities: Analyst, Client and Contractor. Each inherit from a base class User. public abstract class User { public virtual int Id { get; set; } public virtual string Username { get; set; } public virtual string FullName { get; set; } } I then have the other classes inheriting from the base class as: public class Analyst : User { // Empty class. There are no additional properties for an analyst. } public class Client : User { // Empty class. There are no additional properties for a client. } public class Contractor : User { public int TotalJobs { get; set; } public int JobsInProgress { get; set; } } For the above classes, I have the following table structure: USER ---- UserId Username FullName UserType (1 = Analyst, 2 = Client, 3 = Contractor) CONTRACTOR ---------- UserId TotalJobs JobsInProgress There are no tables for Analyst and Client classes. I would like to know how I can write the NHibernate mapping file for the Contractor class. For the other classes, I have created a User mapping file and added Client and Analyst as sub-classes. How can I map the Contractor class?

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  • String Length Evaluating Incorrectly

    - by Justin R.
    My coworker and I are debugging an issue in a WCF service he's working on where a string's length isn't being evaluated correctly. He is running this method to unit test a method in his WCF service: // Unit test method public void RemoveAppGroupTest() { string addGroup = "TestGroup"; string status = string.Empty; string message = string.Empty; appActiveDirectoryServicesClient.RemoveAppGroup("AOD", addGroup, ref status, ref message); } // Inside the WCF service [OperationBehavior(Impersonation = ImpersonationOption.Required)] public void RemoveAppGroup(string AppName, string GroupName, ref string Status, ref string Message) { string accessOnDemandDomain = "MyDomain"; RemoveAppGroupFromDomain(AppName, accessOnDemandDomain, GroupName, ref Status, ref Message); } public AppActiveDirectoryDomain(string AppName, string DomainName) { if (string.IsNullOrEmpty(AppName)) { throw new ArgumentNullException("AppName", "You must specify an application name"); } } We tried to step into the .NET source code to see what value string.IsNullOrEmpty was receiving, but the IDE printed this message when we attempted to evaluate the variable: 'Cannot obtain value of local or argument 'value' as it is not available at this instruction pointer, possibly because it has been optimized away.' (None of the projects involved have optimizations enabled). So, we decided to try explicitly setting the value of the variable inside the method itself, immediately before the length check -- but that didn't help. // Lets try this again. public AppActiveDirectoryDomain(string AppName, string DomainName) { // Explicitly set the value for testing purposes. AppName = "AOD"; if (AppName == null) { throw new ArgumentNullException("AppName", "You must specify an application name"); } if (AppName.Length == 0) { // This exception gets thrown, even though it obviously isn't a zero length string. throw new ArgumentNullException("AppName", "You must specify an application name"); } } We're really pulling our hair out on this one. Has anyone else experienced behavior like this? Any tips on debugging it?

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  • Why does a sub-class class of a class have to be static in order to initialize the sub-class in the

    - by Alex
    So, the question is more or less as I wrote. I understand that it's probably not clear at all so I'll give an example. I have class Tree and in it there is the class Node, and the empty constructor of Tree is written: public class RBTree { private RBNode head; public RBTree(RBNode head,RBTree leftT,RBTree rightT){ this.head=head; this.head.leftT.head.father = head; this.head.rightT.head.father = head; } public RBTree(RBNode head){ this(head,new RBTree(),new RBTree()); } public RBTree(){ this(new RBNode(),null,null); } public class RBNode{ private int value; private boolean isBlack; private RBNode father; private RBTree leftT; private RBTree rightT; } } Eclipse gives me the error: "No enclosing instance of type RBTree is available due to some intermediate constructor invocation" for the "new RBTree()" in the empty constructor. However, if I change the RBNode to be a static class, there is no problem. So why is it working when the class is static. BTW, I found an easy solution for the cunstructor: public RBTree(){ this.head = new RBNode(); } So, I have no idea what is the problem in the first piece of code.

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  • How is this algorithm, for finding maximum path on a Directed Acyclical Graph, called?

    - by Martín Fixman
    Since some time, I'm using an algorithm that runs in complexity O(V + E) for finding maximum path on a Directed Acyclical Graph from point A to point B, that consists on doing a flood fill to find what nodes are accessible from note A, and how many "parents" (edges that come from other nodes) each node has. Then, I do a BFS but only "activating" a node when I already had used all its "parents". queue <int> a int paths[] ; //Number of paths that go to note i int edge[][] ; //Edges of a int mpath[] ; //max path from 0 to i (without counting the weight of i) int weight[] ; //weight of each node mpath[0] = 0 a.push(0) while not empty(a) for i in edge[a] paths[i] += 1 a.push(i) while not empty(a) for i in children[a] mpath[i] = max(mpath[i], mpath[a] + weight[a]) ; paths[i] -= 1 ; if path[i] = 0 a.push(i) ; Is there any special name for this algorithm? I told it to an Informatics professor, he just called it "Maximum Path on a DAG", but it doesn't sound good when you say "I solved the first problem with a Fenwick Tree, the second with Dijkstra, and the third with Maximum Path".

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  • MSSQL in ASP.NET application getting unstable after a certain period

    - by Barslett
    Hello, I have an ASP.NET 2.0 application that I made to keep track of disruption reports about our public transport system. The architecture is pretty straight-forward; an MSSQL Express 2008 database, ADO.NET and a DataSet/DAL with a few methods to access the database. There is a set of .aspx pages for the UI in use by our dispatchers and on our public website, as well as a set of SOAP and REST webservices and an RSS feed. Everything worked just fine for more than a year, until two weeks ago. Now and then, it seems as the database enters an unstable mode, and the application starts responding something right, something wrong. The typical error is that apparently, an empty DataTable is returned to the public disruption overview or to the RSS generator. Thus, the user gets e.g. an empty GridView, but no exception is thrown AFAIK, and nothing is written to the Windows Application log. After a restart of the MSSQL Express service, the situation is back to normal. It has to be said that the situation first time appeared a few days after I made a new minor upgrade of the application. The RSS generator was slightly rewritten, and I added a WCF REST service. But the DAL and the database schema were untouched... Any hints of how we could keep the database stable? It is a bit annoying not to have a clue ;-)

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  • Validating Age field javascript beginner

    - by Marcelo
    Hi people, I'm trying to validate an age field in a form but I'm having some problem. First I tried to make sure that the field will not be send empty. I don't know javascript so I searched some scripts and adapted them to this: function isInteger (s) { var i; if (isEmpty(s)) if (isInteger.arguments.length == 1) return 0; else return (isInteger.arguments[1] == true); for (i = 0; i < s.length; i++) { var c = s.charAt(i); if (!isDigit(c)) return false; } return true; } function isEmpty(s) { return ((s == null) || (s.length == 0)) } function validate_required(field,alerttxt) { with (field) { if (value==null||value=="") { alert(alerttxt);return false; } else { return true; } } } function validate_form(thisform) { with (thisform) { if ((validate_required(age,"Age must be filled out!")==false) || isInteger(age,"Age must be and int number")==false)) {email.focus();return false;} } } //html part <form action="doador.php" onsubmit="return validate_form(this)" method="post"> It's working fine for empty fields, but if I type any letters or characters in age field, it'll be sent and saved a 0 in my database. Can any one help me ? Sorry for any mistake in English, and thanks in andvance for your help.

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  • Need feedback on two member functions of a Table class in C++

    - by George
    int Table::addPlayer(Player player, int position) { deque<Player>::iterator it = playerList.begin()+position; deque<Player>::iterator itStart = playerList.begin()+postion; while(*it != "(empty seat)") { it++; if (it == playerList.end()) { it = playerList.begin(); } if (it == itStart) { cout << "Table full" << endl; return -1; } } //TODO overload Player assignment, << operator *it = player; cout << "Player " << player << " sits at position " << it - playerList.begin() << endl; return it - playerList.begin(); } } int Table::removePlayer(Player player) { deque<Player>::iterator it = playerList.begin(); //TODO Do I need to overload != in Player? while(*it != player) { it++; if (it == playerList.end()) { cout << "Player " << player << " not found" << endl; return -1; } } *it = "(empty seat)"; cout << "Player " << player << " stands up from position " << it - playerList.begin() << endl; return it - playerList.begin(); } Would like some feedback on these two member functions of a Table class for Texas Hold Em Poker simulation. Any information syntax, efficiency or even common practices would be much appreciated.

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  • Populating a foreign key table with variable user input

    - by Vincent
    I'm working on a website that will be based on user contributed data, submitted using a regular HTML form. To simplify my question, let's say that there will be two fields in the form: "User Name" and "Country" (this is just an example, not the actual site). There will be two tables in the database : "countries" and "users," with "users.country_id" being a foreign key to the "countries" table (one-to-many). The initial database will be empty. Users from all over the world will submit their names and the countries they live in and eventually the "countries" table will get filled out with all of the country names in the world. Since one country can have several alternative names, input like Chile, Chili, Chilli will generate 3 different records in the countries table, but in fact there is only one country. When I search for records from Chile, Chili and Chilli will not be included. So my question is - what would be the best way to deal with a situation like this, with conditions such that the initial database is empty, no other resources are available and everything is based on user input? How can I organize it in such way that Chile, Chili and Chilli would be treated as one country, with minimum manual interference. What are the best practices when it comes to normalizing user submitted data and is there a scientific term for this? I'm sure this is a common problem. Again, I used country names just to simplify my question, it can be anything that has possible different spellings.

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  • How to store child objects on GAE using JDO from Scala

    - by Gero
    Hi, I'm have a parent-child relation between 2 classes, but the child objects are never stored. I do get an warning: "org.datanucleus.store.appengine.MetaDataValidator checkForIllegalChildField: Unable to validate relation net.vermaas.kivanotify.model.UserCriteria.internalCriteria" but it is unclear to me why this occurs. Already tried several alternatives without luck. The parent class is "UserCriteria" which has a List of "Criteria" as children. The classes are defined as follows (Scala): class UserCriteria(tu: String, crit: Map[String, String]) extends LogHelper { @PrimaryKey @Persistent{val valueStrategy = IdGeneratorStrategy.IDENTITY} var id = KeyFactory.createKey("UserCriteria", System.nanoTime) @Persistent var twitterUser = tu @Persistent var internalCriteria: java.util.List[Criteria] = flatten(crit) def flatten(crits: Map[String, String]) : java.util.List[Criteria] = { val list = new java.util.ArrayList[Criteria] for (key <- crits.keySet) { list.add(new Criteria(this, key, crits(key))) } list } def criteria: Map[String, String] = { val crits = mutable.Map.empty[String, String] for (i <- 0 to internalCriteria.size-1) { crits(internalCriteria.get(i).name) = internalCriteria.get(i).value } Map.empty ++ crits } // Stripped the equals, canEquals, hashCode, toString code to keep the code snippet short... } @PersistenceCapable @EmbeddedOnly class Criteria(uc: UserCriteria, nm: String, vl: String) { @Persistent var userCriteria = uc @Persistent var name = nm @Persistent var value = vl override def toString = { "Criteria name: " + name + " value: " + value } } Any ideas why the childs are not stored? Or why I get the error message? Thanks, Gero

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  • Creating syncable Calendar in ICS

    - by user1390816
    I have a problem with creating a new Calendar in ICS. The Calendar should be synyable to the google Calendar. I try following: Uri calendarUri = CalendarContract.Calendars.CONTENT_URI; calendar.put(CalendarContract.Calendars.ACCOUNT_NAME, sync_account); calendar.put(CalendarContract.Calendars.ACCOUNT_TYPE, "com.google"); calendar.put(CalendarContract.Calendars.NAME, name); calendar.put(CalendarContract.Calendars.CALENDAR_DISPLAY_NAME, displayName); calendar.put(CalendarContract.Calendars.CALENDAR_COLOR, 0xFF008080); calendar.put(CalendarContract.Calendars.CALENDAR_ACCESS_LEVEL, CalendarContract.Calendars.CAL_ACCESS_OWNER); calendar.put(CalendarContract.Calendars.OWNER_ACCOUNT, true); calendar.put(CalendarContract.Calendars.VISIBLE, 1); calendar.put(CalendarContract.Calendars.SYNC_EVENTS, 1); calendarUri = calendarUri.buildUpon() .appendQueryParameter(CalendarContract.CALLER_IS_SYNCADAPTER, "true") .appendQueryParameter(CalendarContract.Calendars.ACCOUNT_NAME, sync_account) .appendQueryParameter(CalendarContract.Calendars.ACCOUNT_TYPE, "com.google") // CalendarContract.ACCOUNT_TYPE_LOCAL .build(); Uri result = activity.getContentResolver().insert(calendarUri, calendar); an I get always this error: 09-17 17:11:30.278: E/AndroidRuntime(13243): FATAL EXCEPTION: CalendarSyncAdapterAccountMonitor 09-17 17:11:30.278: E/AndroidRuntime(13243): java.lang.IllegalArgumentException: the name must not be empty: null 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.accounts.Account.<init>(Account.java:48) 09-17 17:11:30.278: E/AndroidRuntime(13243): at com.google.android.syncadapters.calendar.CalendarSyncAdapter.onAccountsUpdated(CalendarSyncAdapter.java:1129) 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.accounts.AccountManager$11.run(AccountManager.java:1279) 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.os.Handler.handleCallback(Handler.java:605) 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.os.Handler.dispatchMessage(Handler.java:92) 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.os.Looper.loop(Looper.java:137) 09-17 17:11:30.278: E/AndroidRuntime(13243): at android.os.HandlerThread.run(HandlerThread.java:60) 09-17 17:11:30.293: E/android.os.Debug(1989): !@Dumpstate > dumpstate -k -t -n -z -d -o /data/log/dumpstate_app_error What can I do with the CalendarSyncAdapterAccountMonitor, that it is not empty? Thanks in advance.

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  • ASP.net MVC 2 SPARK - Create "Add New Item" link in spark page.

    - by KarlBear
    I have a web form in SPARK which allow the editing of a Facility class that contains Rooms. When editing the Facility all the Rooms are listed for editing too. The form works fine for editing, but I would like to include a button "Add Room" that adds a new blank room below the existing ones. Any idea how this is accomplished? Currently I am doing this in my SPARK page: [All the Facility editing stuff...] <p>Room</p> <div class="small">Enter the rooms associated with this facility.</div> <div class="add"> <div id="room"> <AddFacilityRoom each="var roomModel in Model.FacilityRooms" RoomModel="roomModel" Index="roomModelIndex" /> </div> <a id="addRoom" class="add" href="events/room/add.mvc">Add a room</a> </div> AddFacilityRoom contains the html elements for editing a room. I would like add.mvc to create a new empty Room class and inject a new identical (but empty) control below the existing ones. Currently, though it opens a new page when the "Add a Room" button is clicked.

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