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  • Returning two or more values from a function

    - by cf_PhillipSenn
    I need to return multiple values from a ColdFusion function in an ajax callback function. Here's what I've got: $('input[name="StateName"]').live('change', function() { var StateID = $(this).parents('tr').attr('id'); var StateName = $(this).val(); $.ajax({ url: 'Remote/State.cfc' ,type: "POST" ,data: { 'method': 'UpdateStateName' ,'StateID': StateID ,'StateName': StateName } ,success: function(result){ if (isNaN(result)) { $('#msg').text(result).addClass('err'); } else { $('#' + result + ' input[name="StateName"]').addClass('changed'); }; } ,error: function(msg){ $('#msg').text('Connection error').addClass('err'); } }); }); If I trap a database error, then the success callback is fired, and the result is Not a Number (It is in fact, the text of the error message). I need the function to also pass back other values. One might be the primary key of the row that caused the error. Another might be the old StateName, so that I can refresh the old value on the screen so that the client will know absolutely for sure that their change did not take effect. I guess I'm breaking the rule of atomicity here and need to fix that, because I'm using result as both the primary key of the row that was updated, or it's the error message if the update fails. I need to return both the primary key and the error message.

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  • ViewController behaving oddly when pushed on the window

    - by ayazalavi
    I am using multiple controller during launch of an application in app delegate. One controller is for registration and the second controller is tabbar. tabbar was loading fine but when I pushed registration controller on window, contents went up by 20 units and I have good white blank screen at bottom. Therefore I recreated frame of my registration view controller in its viewdidload method and slided it 20 units down. The code is self.view.frame = CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height); and code in my app delegate for launch application was - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { if (![self accountExists]) { //code if account does not exists on iphone app database self.registerAccount = [[registerViewController alloc] initWithNibName:@"registerViewController" bundle:nil]; [window addSubview:registerAccount.view]; } else if([self autoLoginForAnyAccount]){ //code for autologin to app } else { self.tabBarController.selectedIndex = 1; self.tabBarController.delegate = self; [window addSubview:tabBarController.view]; } [window makeKeyAndVisible]; return YES; } if anyone knows why there is a white space at bottom when registration controller is pushed then please share it with me.

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  • WinForms: How to determine if window is no longer active (no child window has focus)?

    - by Marek
    My application uses multiple windows I want to hide one specific window in case the application loses focus (when the Active Window is not the application window) source I am handling the Deactivate event of my main form. private void MainForm_Deactivate(object sender, EventArgs e) { Console.WriteLine("deactivate"); if (GetActiveWindow() == this.Handle) { Console.WriteLine("isactive=true"); } else { Console.WriteLine("isactive=false"); } } [DllImport("user32.dll")] static extern IntPtr GetActiveWindow(); The output is always deactivate isactive=true I have observed the same behavior if a new window within my application receives focus and also if I click into a different application. I would expect GetActiveWindow to return the handle of the new active window when called from the Deactivate handler. Instead it always returns the handle of my application window. How is this possible? Is the Deactivate event handled "too soon"? (while the main form is still active?). How can I detect that my application has lost focus (my application window is not the active window) and another application gained it without running GetActiveWindow on a timer?

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  • Passing contextual info to Views in ASP.NET MVC

    - by Andrey
    I wonder - what is the best way to supply contextual (i.e. not related to any particular view, but to all views at the same time) info to a view (or to master page)? Consider the following scenario. Suppose we have an app that supports multiple UI languages. User can switch them via UI's widgets (something like tabs at the top of the page). Each language is rendered as a separate tab. Tab for the current language should not be rendered. To address these requirements I'm planning to have a javascript piece that will hide current's language tab on the client. To do this, I need current's language tab Id on the client. So, I need some way of passing the Id to master page (for it to be 'fused' into the js script). The best thing I can think of is that all my ViewModels should inherit some ViewModeBase that has a field to hold current language tab Id. Then, whatever View I'm rendering, this Id will always be available for the master page's hiding script. However, I'm concerned that this ViewModelBase can potentially grow in an uncontrolled fashion as number of such pieces of contextual info (like current language) will grow.. Any ideas?

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  • How to further improve error messages in Scala parser-combinator based parsers?

    - by rse
    I've coded a parser based on Scala parser combinators: class SxmlParser extends RegexParsers with ImplicitConversions with PackratParsers { [...] lazy val document: PackratParser[AstNodeDocument] = ((procinst | element | comment | cdata | whitespace | text)*) ^^ { AstNodeDocument(_) } [...] } object SxmlParser { def parse(text: String): AstNodeDocument = { var ast = AstNodeDocument() val parser = new SxmlParser() val result = parser.parseAll(parser.document, new CharArrayReader(text.toArray)) result match { case parser.Success(x, _) => ast = x case parser.NoSuccess(err, next) => { tool.die("failed to parse SXML input " + "(line " + next.pos.line + ", column " + next.pos.column + "):\n" + err + "\n" + next.pos.longString) } } ast } } Usually the resulting parsing error messages are rather nice. But sometimes it becomes just sxml: ERROR: failed to parse SXML input (line 32, column 1): `"' expected but `' found ^ This happens if a quote characters is not closed and the parser reaches the EOT. What I would like to see here is (1) what production the parser was in when it expected the '"' (I've multiple ones) and (2) where in the input this production started parsing (which is an indicator where the opening quote is in the input). Does anybody know how I can improve the error messages and include more information about the actual internal parsing state when the error happens (perhaps something like a production rule stacktrace or whatever can be given reasonably here to better identify the error location). BTW, the above "line 32, column 1" is actually the EOT position and hence of no use here, of course.

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  • PHP, MySQL, Memcache / Ajax Scaling Problem

    - by Jeff Andersen
    I'm building a ajax tic tac toe game in PHP/MySQL. The premise of the game is to be able to share a url like mygame.com/123 with your friends and you play multiple simultaneous games. The way I have it set up is that a file (reload.php) is being called every 3 seconds while the user is viewing their game board space. This reload.php builds their game boards and the output (html) replaces their current game board (thus showing games in which it is their turn) Initially I built it entirely with PHP/MySQL and had zero caching. A friend gave me a suggestion to try doing all of the temporary/quick read information through memcache (storing moves, and ID matchups) and then building the game boards from this information. My issue is that, both solutions encounter a wall when there is roughly 30-40 active users with roughly 40-50 games running. It is running on a VPS from VPS.net with 2 nodes. (Dedicated CPU: 1.2GHz, RAM: 752MB) Each call to reload.php peforms 3 selects and 2 insert queries. The size of the data being pulled is negligible. The same actions happen on index.php to build the boards for the initial visit. Now that the backstory is done, my question is: Would there be a bottleneck in that each user is polling the same file every 3 seconds to rebuild their gameboards, and that all users are sitting on index.php from which the AJAX calls are made within the HTML. If so, is it possible to spread the users' calls out over a set of files designated to building the game boards (eg. reload1.php 2, 3 etc) and direct users to the appropriate file. Would this relieve the pressure? A long winded explanation; however, I didn't have anywhere else to ask. Thanks very much for any insight.

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  • Is there any way to make this JavaScript tab completion script more efficient?

    - by Saladin Akara
    This code is to be integrated into an AJAX Chat system to enable a tab auto-completion of user names: var usernames = new Array(); usernames[0] = "Saladin"; usernames[1] = "Jyllaby"; usernames[2] = "CadaverKindler"; usernames[3] = "qbsuperstar03"; var text = "Text and something else q"; // Start of the script to be imported var searchTerm = text.slice(text.lastIndexOf(" ") + 1); var i; for(i = 0; i < usernames.length && usernames[i].substr(0,searchTerm.length) != searchTerm; i++); // End of the script to be imported document.write(usernames[i]); A couple of notes to be made: The array of usernames and the text variable would both be loaded from the chat itself via AJAX (which, unfortunately, I don't know), and the final output will be handled by AJAX as well. Is there a more efficient way to do this? Also, any tips on how to handle multiple instances of the searchTerm being found?

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  • c++ programming- Tryin to get a number within an array that is twice the average

    - by max
    i have been assigned to set up an array with points. I am told to get the maximum value, average, nd within this same array, if any point in the array is twice the average, i should cout an "outlier." So far i have gotten the average and maximum numbers in the array. but i am unable to set the programme to cout the outlier. Instead it gives me a multiple of the average. pls help! here is the programme; int main() { const int max = 10; int ary[max]={4, 32, 9, 7, 14, 12, 13, 17, 19, 18}; int i,maxv; double out,sum=0; double av; maxv= ary[0]; for(i=0; i } cout<<"maximum value: "< for(i=0; i sum = sum + ary[i]; av = sum / max; } cout<<"average: "< out = av * 2; if(ary[i]out) { cout<<"outlier: "< return 0; }

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  • FLVs on timeline are glitching out

    - by TandemAdam
    I have a Movieclip with about five FLV movies embedded on its timeline, one after another. I am loading multiple instances (about 5-10) of this movieclip onto the stage. Once added to the stage, they each play there timelines in a loop. The problem is that when one of the instances switch over to playing a new FLV, then some of the other instances "glitch out"! See this image for what the glitch looks like: This glitch also happens when they first start playing (first load). More details of Flash: 24fps FlashPlayer 10 Actionscript 3 More details of the FLVs: Encoded with On2 VP6 24fps transparent background (alpha channel) dimensions 640x480 filesize are about 150KB each FLVs are imported using option: "Embed video in SWF and play in timeline" Has anyone seen this before? Does anyone have a reason for why this might be happening? And any possibly ways to stop it from happening. EDIT* It seems to only "glitch" when an FLV is started from a random frame (a frame that is not the first frame). I don't think it always does it, but it does it quite often.

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  • Whether to put method code in a VB.Net data storage class, or put it in a separate class?

    - by Alan K
    TLDR summary: (a) Should I include (lengthy) method code in classes which may spawn multiple objects at runtime, (b) does doing so cause memory usage bloat, (c) if so should I "outsource" the code to a class that is loaded only once and have the class methods call that, or alternatively (d) does the code get loaded only once with the object definition anyway and I'm worrying about nothing? ........ I don't know whether there's a good answer to this but if there is I haven't found it yet by searching in the usual places. In my VB.Net (2010 if it matters) WinForms project I have about a dozen or so class objects in an object model. Some of these are pretty simple and do little more than act as data storage repositories. The ones further up the object model, however, have an increasing number of methods. There can be a significant number of higher level objects in use though the exact number will be runtime dependent so I can't be more precise than that. As I was writing the method code for one of the top level ones I noticed that it was starting to get quite lengthy. Memory optimisation is something of a lost art given how much memory the average PC has these days but I don't want to make my application a resource hog. So my questions for anyone who knows .Net way better than I do (of which there will be many) are: Is the code loaded into memory with each instance of the class that's created? Alternatively is it loaded only once with the definition of the class, and all derived objects just refer to that definition? (I'm not really sure how that could be possible given that, for example, event handlers can be assigned dynamically, but no harm asking.) If the answer to the first one is yes, would it be more efficient to write the code in a "utility" object which is loaded only once and called from the real class' methods? Any thoughts appreciated.

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  • inconsistent setTexture behavior in cocos2d on iPhone after using CCAnimate/CCAnimation

    - by chillid
    Hi, I have a character that goes through multiple states. The state changes are reflected by means of a sprite image (texture) change. The state change is triggered by a user tapping on the sprite. This works consistently and quite well. I then added an animation during State0. Now, when the user taps - setTexture gets executed to change the texture to reflect State1, however some of the times (unpredictable) it does not change the texture. The code flows as below: // 1. // Create the animation sequence CGRect frame1Rect = CGRectMake(0,32,32,32); CGRect frame2Rect = CGRectMake(32,32,32,32); CCTexture2D* texWithAnimation = [[CCTextureCache sharedTextureCache] addImage:@"Frames0_1_thinkNthickoutline32x32.png"]; id anim = [[[CCAnimation alloc] initWithName:@"Sports" delay:1/25.0] autorelease]; [anim addFrame:[CCSpriteFrame frameWithTexture:texWithAnimation rect:frame1Rect offset:ccp(0,0)]]; [anim addFrame:[CCSpriteFrame frameWithTexture:texWithAnimation rect:frame2Rect offset:ccp(0,0)]]; // Make the animation sequence repeat forever id myAction = [CCAnimate actionWithAnimation: anim restoreOriginalFrame:NO]; // 2. // Run the animation: sports = [[CCRepeatForever alloc] init]; [sports initWithAction:myAction]; [self.sprite runAction:sports]; // 3. stop action on state change and change texture: NSLog(@"Stopping action"); [sprite stopAction:sports]; NSLog(@"Changing texture for kCJSports"); [self setTexture: [[CCTextureCache sharedTextureCache] addImage:@"SportsOpen.png"]]; [self setTextureRect:CGRectMake(0,0,32,64)]; NSLog(@"Changed texture for kCJSports"); Note that all the NSLog lines get logged - and the texture RECT changes - but the image/texture changes only some of the times - fails for around 10-30% of times. Locking/threading/timing issue somewhere? My app (game) is single threaded and I only use the addImage and not the Async version. Any help much appreciated.

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  • How can I pivot these key+values rows into a table of complete entries?

    - by CodexArcanum
    Maybe I demand too much from SQL but I feel like this should be possible. I start with a list of key-value pairs, like this: '0:First, 1:Second, 2:Third, 3:Fourth' etc. I can split this up pretty easily with a two-step parse that gets me a table like: EntryNumber PairNumber Item 0 0 0 1 0 First 2 1 1 3 1 Second etc. Now, in the simple case of splitting the pairs into a pair of columns, it's fairly easy. I'm interested in the more advanced case where I might have multiple values per entry, like: '0:First:Fishing, 1:Second:Camping, 2:Third:Hiking' and such. In that generic case, I'd like to find a way to take my 3-column result table and somehow pivot it to have one row per entry and one column per value-part. So I want to turn this: EntryNumber PairNumber Item 0 0 0 1 0 First 2 0 Fishing 3 1 1 4 1 Second 5 1 Camping Into this: Entry [1] [2] [3] 0 0 First Fishing 1 1 Second Camping Is that just too much for SQL to handle, or is there a way? Pivots (even tricky dynamic pivots) seem like an answer, but I can't figure how to get that to work.

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  • How can I prevent infinite recursion when using events to bind UI elements to fields?

    - by Billy ONeal
    The following seems to be a relatively common pattern (to me, not to the community at large) to bind a string variable to the contents of a TextBox. class MyBackEndClass { public event EventHandler DataChanged; string _Data; public string Data { get { return _Data; } set { _Data = value; //Fire the DataChanged event } } } class SomeForm : // Form stuff { MyBackEndClass mbe; TextBox someTextBox; SomeForm() { someTextBox.TextChanged += HandleTextBox(); mbe.DataChanged += HandleData(); } void HandleTextBox(Object sender, EventArgs e) { mbe.Data = ((TextBox)sender).Text; } void HandleData(Object sender, EventArgs e) { someTextBox.Text = ((MyBackEndClass) sender).Data; } } The problem is that changing the TextBox fires the changes the data value in the backend, which causes the textbox to change, etc. That runs forever. Is there a better design pattern (other than resorting to a nasty boolean flag) that handles this case correctly? EDIT: To be clear, in the real design the backend class is used to synchronize changes between multiple forms. Therefore I can't just use the SomeTextBox.Text property directly. Billy3

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  • JQuery-AJAX: No further request after timeout and delay in form post

    - by Nogga
    I got a form containing multiple checkboxes. This form shall be sent to the server to receive appropriate results from a server side script. This is already working. What I would achieve now: 1) Implementing a timeout: This is already working, but as soon as a timeout occurs, a new request is not working anymore. 2) Implementing a delay in requesting results: A delay shall be implemented so that not every checkbox is resulting in a POST request. This is what I have right now: function update_listing() { // remove postings from table $('.tbl tbody').children('tr').remove(); // get the results through AJAX var request = $.ajax({ type: "POST", url: "http://localhost/hr/index.php/listing/ajax_csv", data: $("#listing_form").serialize(), timeout: 5000, success: function(data) { $(".tbl tbody").append(data); }, error: function(objAJAXRequest, strError) { $(".tbl tbody").append("<tr><td>failed " + strError + "</td></tr>"); } }); return true; } Results are for now passed as HTML table rows - I will transform them to CSV/JSON in the next step. Thanks so much for your advice.

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  • Can I do something like this?

    - by kumar
    <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<StudentInfo>>" %> <% int i = 0; %> <% foreach(var e in Model){%> <div> <% if(i==0) { %> <% Html.RenderAction("student", "home", new { @et = e}); %> <% break; } %> <div> <span> <% Html.RenderAction("studentDetails", "home", new { @et = e }); %> </span> </div> </div> <%i++; } %> here my intension was to execute Renderction Student only once.. and Studentdetails should be multiple times.. but int value is allways taking i =0 bec each time page is loading its considering 0 allways.. can anybody tell me how to do this? thanks

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  • Send string from java (or other platform) to application

    - by MrSnowflake
    I want to send a barcode, read with my cellphone, to my computer. My computer has a simple server running, which listens to barcodes. When a barcode arrives, the server app should be able to input the value of the received barcode into the active application (I don't really care which application is going to get the input, the user should be able to select gedit, a terminal window or the browser if they choose to). My language at the moment is Java on GNU/Linux (Ubuntu), so I know about the Robot class. But the Robot class emulates a keyboard, which means: when you send VK_1 on a US keyboard layout, the output is '1' indeed, but when you send VK_1 on another layout (like belgian, which I use), which requires shift for the '1' key, the output is '&' (this is the character on the '1' key, when you don't hold shift). I also found xsendkeys, but this application too requires you to specify whether you need to hold shift. So it will be able to send an 'a' but for an 'A' (thus capital) you need to specify you want to hold shift with your 'a'. Isn't there an easy way to do this, for GNU/Linux and Windows, just using strings. I want to be able to send "12a68dd" to the active application. And I also would like to be able to send UTF-8 characters to the active application. I have been looking for a solution, but most require the breakdown in multiple keystrokes, which are often dependent on the keyboard layout.

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  • C# XML parsing with LINQ storing directly to a struct?

    - by Luke
    Say I have the following XML schema: <root> <version>2.0</version> <type>fiction</type> <chapters> <chapter>1</chapter> <title>blah blah</title> </chapter> <chapters> <chapter>2</chapter> <title>blah blah</title> </chapters> </root> Would it be possibly to parse the elements which I know will not be repeated in the XML and store them directly into the struct using LINQ? For example, could I do something like this for "version" and "type" //setup structs Book book = new Book(); book.chapter = new Chapter(); //use LINQ to parse the xml var bookData = from b in xmlDoc.Decendants("root") select new { book.version = b.Element("version").Value, book.type = b.Element("type").Value }; //then for "chapters" since I know there are multiple I can do: var chapterData = from c in xmlDoc.Decendants("root" select new { chapter = c.Element("chapters") }; foreach (var ch in chapterData) { book.chapter.Add(getChapterData(ch.chapter)); }

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  • Rails: How to name and create unique divs within a loop?

    - by sscirrus
    I have a view with a div that is looped many times. Each of the created divs need to have a unique ID so I can access them specifically (at the moment, all my divs have the same ID specified in html so whenever I try to access a specific div it just finds the first one). This is the version that I currently have (multiple 'rowBox'es are not discernible). <% @customers.each do |customer| %> <div id="customer" class="rowBox"> ... </div> <% end %> I would like to be able to do something like: <% @customers.each do |customer| %> <div id="box<%=customer.id%>"> ... </div> <% end %> This doesn't seem to work. Any ideas on how to accomplish this?

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  • Parallelizing L2S Entity Retrieval

    - by MarkB
    Assuming a typical domain entity approach with SQL Server and a dbml/L2S DAL with a logic layer on top of that: In situations where lazy loading is not an option, I have settled on a convention where getting a list of entities does not also get each item's child entities (no loading), but getting a single entity does (eager loading). Since getting a single entity also gets children, it causes a cascading effect in which each child then gets its children too. This sounds bad, but as long as the model is not too deep, I usually don't see performance problems that outweigh the benefits of the ease of use. So if I want to get a list in which each of the items is fully hydrated with children, I combine the GetList and GetItem methods. So I'll get a list and then loop through it getting each item with the full cascade. Even this is generally acceptable in many of the projects I've worked on - but I have recently encountered situations with larger models and/or more data in which it needs to be more efficient. I've found that partitioning the loop and executing it on multiple threads yields excellent results. In my first experiment with a list of 50 items from one particular project, I did 5 threads of 10 items each and got a 3X improvement in time. Of course, the mileage will vary depending on the project but all else being equal this is clearly a big opportunity. However, before I go further, I was wondering what others have done that have already been through this. What are some good approaches to parallelizing this type of thing?

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  • xpath php attributes not working?

    - by Jared
    Getting this error Call to a member function attributes() on a non-object I have found multiple answers to this on SO, but none of them seem to solve my problem? Here is the XML: <Routes> <Route type="source" name="incoming"> </Route> <Routes> Here is the PHP: $doc = new SimpleXMLElement('routingConfig.xml', null, true); class traverseXML { function getData() { global $doc; $routeCount = count($doc -> xpath("Route")); //this value returns correctly $routeArr = array(); for ($i = 1; $i <= $routeCount; $i++) { $name = $doc -> Route[$i] -> attributes() -> name; array_push($routeArr, $name); } return $routeArr; } } $traverseXML = new traverseXML; var_dump($traverseXML -> getData()); I understand what the error means, but how is it a non-object? How do I return the name attribute of Routes/Route[1] ?

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  • File IO with Streams - Best Memory Buffer Size

    - by AJ
    I am writing a small IO library to assist with a larger (hobby) project. A part of this library performs various functions on a file, which is read / written via the FileStream object. On each StreamReader.Read(...) pass, I fire off an event which will be used in the main app to display progress information. The processing that goes on in the loop is vaired, but is not too time consuming (it could just be a simple file copy, for example, or may involve encryption...). My main question is: What is the best memory buffer size to use? Thinking about physical disk layouts, I could pick 2k, which would cover a CD sector size and is a nice multiple of a 512 byte hard disk sector. Higher up the abstraction tree, you could go for a larger buffer which could read an entire FAT cluster at a time. I realise with today's PC's, I could go for a more memory hungry option (a couple of MiB, for example), but then I increase the time between UI updates and the user perceives a less responsive app. As an aside, I'm eventually hoping to provide a similar interface to files hosted on FTP / HTTP servers (over a local network / fastish DSL). What would be the best memory buffer size for those (again, a "best-case" tradeoff between perceived responsiveness vs. performance).

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  • jQuery: Add Numbers into an Ordered List

    - by qwer0o
    I would like to use jQuery to make this: <ol> <li>item a</li> <li>item b</li> </ol> <ol> <li>item c</li> <li>item d</li> <li>item e</li> </ol> …become this: <ol> <li><span>1</span> item a</li> <li><span>2</span> item b</li> </ol> <ol> <li><span>1</span> item c</li> <li><span>2</span> item d</li> <li><span>3</span> item e</li> </ol> (This answer doesn't work for when there are multiple ols on the page; the number would increment across the ols instead of starting from 1 for each individual ol.)

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  • Polling a web URL until event

    - by Jaxo
    I'm really sorry about the crappy title - if anybody has a better way of wording it, please edit it! I basically need to have a C# application run a function if the output of a URL is a certain value. For example, if the website says blue the background colour will be blue, red to make it red, etc. The problem is I don't want to spam my webserver with checks. The 4 bytes it downloads each time is negligible, but if I were to deploy this type of system on multiple computers, it would get slower and slower and the bandwidth would add up quickly. So my question is: How can my desktop application run a piece of code only when a web URL has a different output without checking each time? I can't use sockets, and any sort of LAN protocol won't end up working. My reasoning behind this potentially nefarious code is to be able to mute computers by updating a file on the website (as you may have seen in my previous question today, sorry!). I'd like it to be rather quick, and not have the refresh time minutes apart, a few seconds at the most would be ideal. How can I accomplish this? The website's code is easy, but getting the C# application to check when it changes is the part I'm stuck on. Nothing shows up on the website other than the command. Thanks!

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  • Periodically iterating over a collection that's constantly changing

    - by rwmnau
    I have a collection of objects that's constantly changing, and I want to display some information about objects (my application is multi-threaded, and differently threads are constantly submitting requests to modify an object in the collection, so it's unpredictable), and I want to display some information about what's currently in the collection. If I lock the collection, I can iterate over it and get my information without any problems - however, this causes problems with the other threads, since they could have submitted multiple requests to modify the collection in the meantime, and will be stalled. I've thought of a couple ways around this, and I'm looking for any advice. Make a copy of the collection and iterate over it, allowing the original to continue updating in the background. The collection can get large, so this isn't ideal, but it's safe. Iterate over it using a For...Next loop, and catch an IndexOutOfBounds exception if an item is removed from the collection while we're iterating. This may occasionally cause duplicates to appear in my snapshot, so it's not ideal either. Any other ideas? I'm only concerned about a moment-in-time snapshot, so I'm not concerned about reflecting changes in my application - my main concern is that the collection be able to be updated with minimal latency, and that updates never be lost.

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  • Importing a C DLL's functions into a C++ program

    - by bobobobo
    I have a 3rd party library that's written in C. It exports all of its functions to a DLL. I have the .h file, and I'm trying to load the DLL from my C++ program. The first thing I tried was surrounding the parts where I #include the 3rd party lib in #ifdef __cplusplus extern "C" { #endif and, at the end #ifdef __cplusplus } // extern "C" #endif But the problem there was, all of the DLL file function linkage looked like this in their header files: a_function = (void *)GetProcAddress(dll, "a_function"); While really a_function had type int (*a_function) (int *). Apparently MSVC++ compiler doesn't like this, while MSVC compiler does not seem to mind. So I went through (brutal torture) and fixed them all to the pattern typedef int (*_a_function) (int *); _a_function a_function ; Then, to link it to the DLL code, in main(): a_function = (_a_function)GetProcAddress(dll, "a_function"); This SEEMS to make the compiler MUCH, MUCH happier, but it STILL complains with this final set of 143 errors, each saying for each of the DLL link attempts: error LNK2005: _a_function already defined in main.obj main.obj Multiple symbol definition errors.. sounds like a job for extern! SO I went and made ALL the function pointer declarations as follows: function_pointers.h typedef int (*_a_function) (int *); extern _a_function a_function ; And in a cpp file: function_pointers.cpp #include "function_pointers.h" _a_function a_function ; ALL fine and dandy.. except for linker errors now of the form: error LNK2001: unresolved external symbol _a_function main.obj Main.cpp includes "function_pointers.h", so it should know where to find each of the functions.. I am bamboozled. Does any one have any pointers to get me functional? (Pardon the pun..)

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