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• How to prevent chrome from injecting content to webpage

  - by Nazariy

  Recently I have discovered that my application is misbehaving in Google Chrome. On a page with a form, after it was submitted, my application reloads page using simple method like this: header('Location: ' . $url); after that, page is rendered incorrectly and this content is injected to DOM <div id="sbi_camera_button" class="sbi_search" style="left: 0px; top: 0px; position: absolute; width: 29px; height: 27px; border: none; margin: 0px; padding: 0px; z-index: 2147483647; display: none; "></div> After manual page refresh everything works as expected. I'm not sure what causing this behavior, as I'm working in closed local environment and application works fine in Firefox. My application using following libraries (hosted locally): jQuery v1.7.1 jQuery UI 1.8.16 Bootstrap.js v 2.1.1 Can someone suggest me what can possibly cause this issue?

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• How can I get the main thread to sleep while waiting for a delgate to be called?

  - by Erik B

  Consider a class with these methods: - (id) initWithFrame: (CGRect) frame { if (!(self = [super init])) return nil; webView = [[UIWebView alloc] initWithFrame:frame]; [webView setDelegate:self]; lock = [[NSConditionLock alloc] initWithCondition:LOCK_WAIT]; return self; } - (void) setHTML: (NSString *) html { [lock lockWhenCondition:LOCK_WAIT]; [webView loadHTMLString:html baseURL:nil]; [lock unlock]; } - (void)webViewDidFinishLoad:(UIWebView *)aWebView { [lock lockWhenCondition:LOCK_WAIT]; // Locking to be able to unlock and change the condition. [lock unlockWithCondition:LOCK_GO]; } - (NSString *) stringByEvaluatingJavaScriptFromString: (NSString *) jsCommand { [lock lockWhenCondition:LOCK_GO]; return [webView stringByEvaluatingJavaScriptFromString:jsCommand]; [lock unlock]; } Let's call this class SynchronousUIWebView. From the main thread I execute: webView = [[SynchronousUIWebView alloc] initWithFrame:frame]; [webView setHTML:html]; [webView stringByEvaluatingJavaScriptFromString:jsCommand]; The problem seems to be that the delegate is not called until I leave the current call stack, which I don't since I'm waiting for the delegate call to happen, aka deadlock. To me it seems like the delegate call is pushed to a queue that is called when the current call is done. So the question is can I modify this behavior? Note: The reason this is needed is that I can't execute the JavaScript until the HTML has loaded.

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• VirtualBox limits size of .js file, that can be included from guest additions folder?

  - by c69

  This question might belong to SuperUser, but i'll try to ask it here anyway, because i believe, some web developers might encountered this weird behavior. When testing a site for IE8/winXP compatibility on VirtualBox i run into weird issue of $ is undefined, which is caused by jQuery (and jQuery UI) being not included, when referenced by relative path, which resolves to file:/// url. Seemingly because their size was too big (above 200KB). Simply replacing links to those 2 big files to http:// ones solved the issue for me. But here is the question: why did this happen ? is it a misconfiguration ? a bug ? a known design decision ? Details: VirtualBox 4.1.8 host os: win7 64bit, guest os: xp sp3 32 bit guest additions installed, page was launched from VB shared folder the bug was manifesting itself in all browsers (even in opera, which ignores ie security settings, afaik) ie configuration is default script was included like this: <script type="text/javascript" src="js/libs/jquery/jquery-1.7.2.js"> exact size limit was not deducted.

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• Rename files and directories using substitution and variables

  - by rednectar

  I have found several similar questions that have solutions, except they don't involve variables. I have a particular pattern in a tree of files and directories - the pattern is the word TEMPLATE. I want a script file to rename all of the files and directories by replacing the word TEMPLATE with some other name that is contained in the variable ${newName} If I knew that the value of ${newName} was say "Fred lives here", then the command find . -name '*TEMPLATE*' -exec bash -c 'mv "$0" "${0/TEMPLATE/Fred lives here}"' {} \; will do the job However, if my script is: newName="Fred lives here" find . -name '*TEMPLATE*' -exec bash -c 'mv "$0" "${0/TEMPLATE/${newName}}"' {} \; then the word TEMPLATE is replaced by null rather than "Fred lives here" I need the "" around $0 because there are spaces in the path name, so I can't do something like: find . -name '*TEMPLATE*' -exec bash -c 'mv "$0" "${0/TEMPLATE/"${newName}"}"' {} \; Can anyone help me get this script to work so that all files and directories that contain the word TEMPLATE have TEMPLATE replaced by whatever the value of ${newName} is eg, if newName="A different name" and a I had directory of /foo/bar/some TEMPLATE directory/with files then the directory would be renamed to /foo/bar/some A different name directory/with files and a file called some TEMPLATE file would be renamed to some A different name file

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• How to develop for iphone application about "retrieving database file on web"?

  - by coverboy

  Hi...all experts! I'm a newbie to iphone developer. Well, currently, I'm developing iphone for Location Based Service. That application need to have these functions. 1. hierarchical tree-view on navigation bar. 2. list up page 3. detail page for example, Let's say. I have top category like "Restaurant, Hotel, Gift Shop" Second level "New York, LA, London,....." Third Level displays all Data with 1 photo. Fourth Level displays Detail of that "Restaurant or Hotel, Gift shop, ..." So, My Only Interest is "How to retrieve the data from remote database server. not using iphone local one." Because, that locations, and shops should be updated frequently, (you know some shops closed, new shops opens.) So, till now, I figured out that using XML to retrieve data. However, using XML is the most effective way to implement? Is there any other way to accomplish this work? You know, transferring XML data via 3G Network is really slow. XML file have more bytes than plist file. I'm currently a beginner of iphone development. So, please help me find a right way!! And, one more question, if I use xml way. Is it possible to Paging? (First page 10 lists up, below that more button...) well, you might guess each category have hundreds of shops!!

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• Hibernate is persisting entity during flush when the entity has not changed

  - by Preston

  I'm having a problem where the entity manger is persisting an entity that I don't think has changed during the flush. I know the following code is the problem because if I comment it out the entity doesn't persist. In this code all I'm doing is loading the entity and calling some getters. Query qry = em.createNamedQuery("Clients.findByClientID"); qry.setParameter("clientID", clientID); Clients client = (Clients) qry.getSingleResult(); results.setFname(client.getFirstName()); results.setLname(client.getLastName()); ... return results; Later in a different method I do another namedQuery which causes the entity manger to flush. For some reason the client loaded above is persisted. The reason this is a problem is because in the middle of all this, there is some old code that is making some straight JDBC changes to the client. When the entity manger persists the changes made by the straight JDBC are lost. The theory we have at moment is that the entity manger is comparing the entity to the underlying record, sees that it's different, then persists it. Can someone explain or confirm the behavior we're seeing?

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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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• Building a control-flow graph from an AST with a visitor pattern using Java

  - by omegatai

  Hi guys, I'm trying to figure out how to implement my LEParserCfgVisitor class as to build a control-flow graph from an Abstract-Syntax-Tree already generated with JavaCC. I know there are tools that already exist, but I'm trying to do it in preparation for my Compilers final. I know I need to have a data structure that keeps the graph in memory, and I want to be able to keep attributes like IN, OUT, GEN, KILL in each node as to be able to do a control-flow analysis later on. My main problem is that I haven't figured out how to connect the different blocks together, as to have the right edge between each blocks depending on their nature: branch, loops, etc. In other words, I haven't found an explicit algorithm that could help me build my visitor. Here is my empty Visitor. You can see it works on basic langage expressions, like if, while and basic operations (+,-,x,^,...) public class LEParserCfgVisitor implements LEParserVisitor { public Object visit(SimpleNode node, Object data) { return data; } public Object visit(ASTProgram node, Object data) { data = node.childrenAccept(this, data); return data; } public Object visit(ASTBlock node, Object data) { } public Object visit(ASTStmt node, Object data) { } public Object visit(ASTAssignStmt node, Object data) { } public Object visit(ASTIOStmt node, Object data) { } public Object visit(ASTIfStmt node, Object data) { } public Object visit(ASTWhileStmt node, Object data) { } public Object visit(ASTExpr node, Object data) { } public Object visit(ASTAddExpr node, Object data) { } public Object visit(ASTFactExpr node, Object data) { } public Object visit(ASTMultExpr node, Object data) { } public Object visit(ASTPowerExpr node, Object data) { } public Object visit(ASTUnaryExpr node, Object data) { } public Object visit(ASTBasicExpr node, Object data) { } public Object visit(ASTFctExpr node, Object data) { } public Object visit(ASTRealValue node, Object data) { } public Object visit(ASTIntValue node, Object data) { } public Object visit(ASTIdentifier node, Object data) { } } Can anyone give me a hand? Thanks!

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• Toggle two divs and classes

  - by kuswantin

  I have two links with classes (login-form and register-form) relevant to their target forms ID, they want to toggle. I have also a predefined 'slideToggle' function to toggle better. This is what I have tried so far: $('#userbar a').click(function() { var c = $(this).attr('class'); $('#userbar a').removeClass('active'); $(this).toggleClass('active'); $('#register-form,#login-form').hide(); //bad, causing flashy $('#' + c).slideToggle('slow'); return false; }); With this I have trouble with the flashy window, and to correctly toggle the active classes when another link is clicked, the other link should not have active class anymore. Additional problem is the link is dead on serial clicks. I have another try, longer one: $('#userbar a').click(function() { var c = $(this).attr('class'); switch (c) { case 'login-form': $('#' + c).slideToggle('slow'); $(this).toggleClass('active'); $('#register-form').hide(); break; case 'register-form': $('#' + c).slideToggle('slow'); $(this).toggleClass('active'); $('#login-form').hide(); break; } return false; }); This one is worse than the first :( Any suggestion to correct the behavior? What I want is when a link with class login-form is click, so toggle the form with ID login-form, and hide the register-form if open. Any help would be very much appreciated. Thanks.

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• Why does TrimStart trims a char more when asked to trim "PRN.NUL" ?

  - by James

  Here is the code: namespace TrimTest { class Program { static void Main(string[] args) { string ToTrim = "PRN.NUL"; Console.WriteLine(ToTrim); string Trimmed = ToTrim.TrimStart("PRN.".ToCharArray()); Console.WriteLine(Trimmed); ToTrim = "PRN.AUX"; Console.WriteLine(ToTrim); Trimmed = ToTrim.TrimStart("PRN.".ToCharArray()); Console.WriteLine(Trimmed); ToTrim = "AUX.NUL"; Console.WriteLine(ToTrim); Trimmed = ToTrim.TrimStart("AUX.".ToCharArray()); Console.WriteLine(Trimmed); } } } The output is like this: PRN.NUL UL PRN.AUX AUX AUX.NUL NUL As you can see, the TrimStart took out the N from NUL. But it doesn't do that for other strings even if it started with PRN. I tried with .NET Framework 3.5 and 4.0 and the results are same. Are there any explanation on what causes this behavior?

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• UITabBarController with viewControllers utilizing different orientations?

  - by RickiG

  Hi I can see that this is something that has been troubling a lot of people:/ I have a UITabBarController that has 4 viewControllers, all of type UINavigationController. One of the navigationControllers gets a viewController pushed onto its stack, this viewController should be presented in landscape mode/orientation. The viewController is a graph, it is the absolutely only place in the app where landscape makes sense. (I hide the UITabBar when this is presented to not lead the user to believe this will work everywhere) To make a UITabBarController respond correctly to changes in orientation all its viewControllers need to return the same value from the delegate method: - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation So to accomodate this behavior I have implemented this method in all the viewControllers belonging to the UITabBarController: - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; BOOL canRotate = [defaults boolForKey:@"can_rotate"]; return canRotate; } The "trick" is now that when my can-be-landscape viewController is pushed I do this: - (void) viewWillAppear:(BOOL)animated { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setBool:YES forKey:@"can_rotate"]; [defaults synchronize]; } and when it is popped, I do this: - (void) viewWillDisappear:(BOOL)animated { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setBool:NO forKey:@"can_rotate"]; [defaults synchronize]; } This works really well. When the viewController is on the stack I can rotate the device and the view follows. The problem is however, that if the user taps the "back" button on the navigationBar while in landscape mode, thus popping the viewController to the previous viewController, this "old" viewController is of course also in landscape mode. To make things worse, because I set the BOOL to NO, this "old" viewController can not rotate back when I orientate the device to portrait mode. Is there a way to update everything so that none of my other viewControllers will be in landscape mode when I pop the can-be-in-landscape mode viewController? I am a bit worried that if this could be done from landscape to portrait it should also be possible from portrait to landscape, thus making my "hack" unnecessary.. but if it can not, then I am back to square one :/ Hope I am close and that someone could help me get there, thanks:)

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• Skip HTML escape in custom label_tag helper in Rail 3

  - by tricote

  Hi, I have this nice class ErrorFormBuilder that allows me to add the error description near the corresponding field in the form view : class ErrorFormBuilder < ActionView::Helpers::FormBuilder #Adds error message directly inline to a form label #Accepts all the options normall passed to form.label as well as: # :hide_errors - true if you don't want errors displayed on this label # :additional_text - Will add additional text after the error message or after the label if no errors def label(method, text = nil, options = {}) #Check to see if text for this label has been supplied and humanize the field name if not. text = text || method.to_s.humanize #Get a reference to the model object object = @template.instance_variable_get("@#{@object_name}") #Make sure we have an object and we're not told to hide errors for this label unless object.nil? || options[:hide_errors] #Check if there are any errors for this field in the model errors = object.errors.on(method.to_sym) if errors #Generate the label using the text as well as the error message wrapped in a span with error class text += " <br/><span class=\"error\">#{errors.is_a?(Array) ? errors.first : errors}</span>" end end #Add any additional text that might be needed on the label text += " #{options[:additional_text]}" if options[:additional_text] #Finally hand off to super to deal with the display of the label super(method, text, options) end end But the HTML : text += " <br/><span class=\"error\">#{errors.is_a?(Array) ? errors.first : errors}</span>" is escaped by default in the view... I tried to add the {:escape = false} option : super(method, text, options.merge({:escape => false})) without success Is there any way to bypass this behavior ? Thanks

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• How to disable firefox's form auto completion without change events?

  - by Dmitriy Likhten

  So firefox has a nifty mechanism which will try to autocomplete values in fields when a page is reloaded or the back button is used. Which is great and all except when you have something like a drop-down which when set to a value modifies the page using ajax. What winds up happening is that the browser reloads the page, the drop down is pre-filled with the remembered value, and then no change event is fired when the dom is ready. And therefore the change handlers attached don't fire and thus the page does not update. Is there a good way to "fix" this behavior so that it works for the user as expected: a) We do want the browser to auto-complete because that is a good user experience. b) Still want that onchange event firing. The only thing I can think of doing at the moment is to add an on-ready event to the document which has javascript pre-populated with initial values in the form, when the document loads the javascript will check the pre-populated values and if not matching what is in the input will trigger the change handlers. Anyone have a better solution? Is there a lib that does this already? (Using Rails 2.3.5 + jQuery)

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• How can I make a family of singletons?

  - by Jay

  I want to create a set of classes that share a lot of common behavior. Of course in OOP when you think that you automatically think "abstract class with subclasses". But among the things I want these classes to do is to each have a static list of instances of the class. The list should function as sort of a singleton within the class. I mean each of the sub-classes has a singleton, not that they share one. "Singleton" to that subclass, not a true singleton. But if it's a static, how can I inherit it? Of course code like this won't work: public abstract A { static List<A> myList; public static List getList() { if (myList==null) myList=new ArrayList<A>(10); return myList; } public static A getSomethingFromList() { List listInstance=getList(); ... do stuff with list ... } public int getSomethingFromA() { ... regular code acting against current instance ... } } public class A1 extends A { ... } public class A2 extends A { ... } A1 somethingfromA1List=(A1) A1.getSomethingFromList(); A2 somethingfromA2List=(A2) A2.getSomethingFromList(); The contents of the list for each subclass would be different, but all the code to work on the lists would be the same. The problem with the above code is that I'd only have one list for all the subclasses, and I want one for each. Yes, I could replicate the code to declare the static list in each of the subclasses, but then I'd also have to replicate all the code that adds to the lists and searches the list, etc, which rather defeats the purpose of subclassing. Any ideas on how to do this without replicating code?

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• Determining what action an NPC will take, when it is partially random but influenced by preferences?

  - by lala

  I want to make characters in a game perform actions that are partially random but also influenced by preferences. For instance, if a character feels angry they have a higher chance of yelling than telling a joke. So I'm thinking about how to determine which action the character will take. Here are the ideas that have come to me. Solution #1: Iterate over every possible action. For each action do a random roll, then add the preference value to that random number. The action with the highest value is the one the character takes. Solution #2: Assign a range of numbers to an action, with more likely actions having a wider range. So, if the random roll returns anywhere from 1-5, the character will tell a joke. If it returns 6-75, they will yell. And so on. Solution #3: Group all the actions and make a branching tree. Will they take a friendly action or a hostile action? The random roll (with preference values added) says hostile. Will they make a physical attack or verbal? The random roll says verbal. Keep going down the line until you reach the action. Solution #1 is the simplest, but hardly efficient. I think Solution #3 is a little more complicated, but isn't it more efficient? Does anyone have any more insight into this particular problem? Is #3 the best solution? Is there a better solution?

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• Performance impact when using XML columns in a table with MS SQL 2008

  - by Sam Dahan

  I am using a simple table with 6 columns, 3 of which are of XML type, not schema-constrained. When the table reaches a size around 120,000 or 150,000 rows, I see a dramatic performance cost in doing any query in the table. For comparison, I have another table, which grows in size at about the same rate, but only contain scalar types (int, datetime, a few float columns). That table performs perfectly fine even after 200,000 rows. And by the way, I am not using XQuery on the xml columns, i am only using regular SQL query statements. Some specifics: both tables contain a DateTime field called SampleTime. a statement like (it's in a stored procedure but I show you the actual statement) SELECT MAX(sampleTime) SampleTime FROM dbo.MyRecords WHERE PlacementID=@somenumber takes 0 seconds on the table without xml columns, and anything from 13 to 20 seconds on the table with XML columns. That depends on which drive I set my database on. At the moment it sits on a different spindle (not C:) and it takes 13 seconds. Has anyone seen this behavior before, or have any hint at what I am doing wrong? I tried this with SQL 2008 EXPRESS and the full-blown SQL Server 2008, that made no difference. Oh, one last detail: I am doing this from a C# application, .NET 3.5, using SqlConnection, SqlReader, etc.. I'd appreciate some insight into that, thanks! Sam

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• __toString magic and type coercion

  - by TomcatExodus

  I've created a Template class for managing views and their associated data. It implements Iterator and ArrayAccess, and permits "sub-templates" for easy usage like so: <p><?php echo $template['foo']; ?></p> <?php foreach($template->post as $post): ?> <p><?php echo $post['bar']; ?></p> <?php endforeach; ?> Anyways, rather than using inline core functions, such as hash() or date(), I figured it would be useful to create a class called TemplateData, which would act as a wrapper for any data stored in the templates. This way, I can add a list of common methods for formatting, for example: echo $template['foo']->asCase('upper'); echo $template['bar']->asDate('H:i:s'); //etc.. When a value is set via $template['foo'] = 'bar'; in the controllers, the value of 'bar' is stored in it's own TemplateData object. I've used the magic __toString() so when you echo a TemplateData object, it casts to (string) and dumps it's value. However, despite the mantra controllers and views should not modify data, whenever I do something like this: $template['foo'] = 1; echo $template['foo'] + 1; //exception It dies on a Object of class TemplateData could not be converted to int; Unless I recast $template['foo'] to a string: echo ((string) $template['foo']) + 1; //outputs 2 Sort of defeats the purpose having to jump through that hoop. Are there any workarounds for this sort of behavior that exist, or should I just take this as it is, an incidental prevention of data modification in views?

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• Testing ActionFilterAttributes with MSpec

  - by Tomas Lycken

  I'm currently trying to grasp MSpec, mainly to learn new ways of (T/B)DD to be able to make an educated decision on which technology to use. Previously, I've mostly (read: only) used the built-in MSTest framework with Moq, so BDD is quite new for me. I'm writing an ASP.NET MVC app, and I want to implement PRG. Last time I did this, I used action filters to export and import ModelState via TempData, so that I could return a RedirectResult and the validation errors would still be there when the user got the view. I tested that scenario by verifying two things: a) That the ExportModelStateAttribute I had written was applied (among tests for my controller) b) That the attribute worked (among tests for action filter attributes) However, in BDD I've understood I should be even more concerned with behavior, and even less with implementation. This means I should probably just verify that the model state is in tempdata when the action has finished executing - not necessarily that it's done via an attribute. To further complicate things, attributes are not run when calling the action directly in the test, so I can't just call the action and see if the job's been done. How should I spec/test this in MSpec?

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• Nose2 multiprocess error on Windows7

  - by tt293

  I was looking into nose2 as a way to get around the restrictions of having both xunit output and multiprocessing in nose1.3. However, when always-on is set to False in the [multiprocess] section, I can only get a single process running, while when running with always-on set to True, I get the following error: ---------------------------------------------------------------------- Ran 0 tests in 0.043s OK Traceback (most recent call last): File "C:\dev\testing\Tests\PythonTests\venv\Scripts\nose2-script.py", line 8, in <module> load_entry_point('nose2==0.4.7', 'console_scripts', 'nose2')() File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 284, in discover return main(*args, **kwargs) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 98, in __init__ super(PluggableTestProgram, self).__init__(**kw) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\unittest2-0.5.1- py2.7.egg\unittest2\main.py", line 98, in __init__ self.runTests() File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 260, in runTests self.result = runner.run(self.test) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\runner.py", line 53, in run executor(test, result) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\plugins\mp.py", line 60, in _runmp ready, _, _ = select.select(rdrs, [], [], self.testRunTimeout) select.error: (10038, 'An operation was attempted on something that is not a soc ket') This is running python 2.7.5 (32bit) on Windows 7 in a virtualenv with six-1.1.0, unittest2-0.5.1 and nose2-0.4.7 (I get the same behavior outside of the venv, so I don't think that is the issue here).

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• Performance difference in for loop condition?

  - by CSharperWithJava

  Hello all, I have a simple question that I am posing mostly for my curiousity. What are the differences between these two lines of code? (in C++) for(int i = 0; i < N, N > 0; i++) for(int i = 0; i < N && N > 0; i++) The selection of the conditions is completely arbitrary, I'm just interested in the differences between , and &&. I'm not a beginner to coding by any means, but I've never bothered with the comma operator. Are there performance/behavior differences or is it purely aesthetic? One last note, I know there are bigger performance fish to fry than a conditional operator, but I'm just curious. Indulge me. Edit Thanks for your answers. It turns out the code that prompted this question had misused the comma operator in the way I've described. I wondered what the difference was and why it wasn't a && operator, but it was just written incorrectly. I didn't think anything was wrong with it because it worked just fine. Thanks for straightening me out.

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• Is a control's OnInit called even when attaching it during parent's OnPreRender?

  - by Xerion

  My original understanding was that the asp.net page lifecycle is run once for all pages and controls under normal circumstances. When I attached a control during a container's OnPreRender, I encountered a situation where the control's OnInit was not called. OK, I considered that a bug in my code and fixed as such, by attaching the control earlier. But just today, I encountered a situation where OnInit for a control seems to be called after the normal OnInit has been done for everyone else. See stack below. It seems that during the page's PreRender, the control's OnInit is called as it is being dynamically added. So I just want to confirm exactly what ASP.NET's behavior is? Does it actually keep track of the stage of each control's lifecycle, and upon adding a new control, it will run from the very beginning? [HttpException (0x80004005): The control collection cannot be modified during DataBind, Init, Load, PreRender or Unload phases.] System.Web.UI.ControlCollection.Add(Control child) +8678663 MyCompany.Web.Controls.SetStartPageWrapper.Initialize() MyCompany.Web.Controls.SetStartPageWrapper.OnInit(EventArgs e) System.Web.UI.Control.InitRecursive(Control namingContainer) +333 System.Web.UI.Control.InitRecursive(Control namingContainer) +210 System.Web.UI.Control.AddedControl(Control control, Int32 index) +198 System.Web.UI.ControlCollection.Add(Control child) +80 MyCompany.Web.Controls.PageHeader.OnPreRender(EventArgs e) in System.Web.UI.Control.PreRenderRecursiveInternal() +80 System.Web.UI.Control.PreRenderRecursiveInternal() +171 System.Web.UI.Control.PreRenderRecursiveInternal() +171 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842

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• Visibility of reintroduced constructor

  - by avenmore

  I have reintroduced the form constructor in a base form, but if I override the original constructor in a descendant form, the reintroduced constructor is no longer visible. type TfrmA = class(TForm) private FWndParent: HWnd; public constructor Create(AOwner: TComponent; const AWndParent: Hwnd); reintroduce; overload; virtual; end; constructor TfrmA.Create(AOwner: TComponent; const AWndParent: Hwnd); begin FWndParent := AWndParent; inherited Create(AOwner); end; type TfrmB = class(TfrmA) private public end; type TfrmC = class(TfrmB) private public constructor Create(AOwner: TComponent); override; end; constructor TfrmC.Create(AOwner: TComponent); begin inherited Create(AOwner); end; When creating: frmA := TfrmA.Create(nil, 0); frmB := TfrmB.Create(nil, 0); frmC := TfrmC.Create(nil, 0); // Compiler error My work-around is to override the reintroduced constructor or to declare the original constructor overloaded, but I'd like to understand the reason for this behavior. type TfrmA = class(TForm) private FWndParent: HWnd; public constructor Create(AOwner: TComponent); overload; override; constructor Create(AOwner: TComponent; const AWndParent: Hwnd); reintroduce; overload; virtual; end; type TfrmC = class(TfrmB) private public constructor Create(AOwner: TComponent; const AWndParent: Hwnd); override; end;

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• Error in Python's os.walk?

  - by Mike Caron

  The os.walk documentation (http://docs.python.org/library/os.html? highlight=os.walk#os.walk), says I can skip traversing unwanted directories by removing them from the dir list. The explicit example from the docs: import os from os.path import join, getsize for root, dirs, files in os.walk('python/Lib/email'): print root, "consumes", print sum(getsize(join(root, name)) for name in files), print "bytes in", len(files), "non-directory files" if 'CVS' in dirs: dirs.remove('CVS') # don't visit CVS directories I see different behavior (using ActivePython 2.6.2). Namely for the code: >>> for root,dirs,files in os.walk(baseline): ... if root.endswith(baseline): ... for d in dirs: ... print "DIR: %s" % d ... if not d.startswith("keep_"): ... print "Removing %s\\%s" % (root,d) ... dirs.remove(d) ... ... print "ROOT: %s" % root ... I get the output: DIR: two Removing: two DIR: thr33 Removing: thr33 DIR: keep_me DIR: keep_me_too DIR: keep_all_of_us ROOT: \\mach\dirs ROOT: \\mach\dirs\ONE ROOT: \\mach\dirs\ONE\FurtherRubbish ROOT: \\mach\dirs\ONE\FurtherRubbish\blah ROOT: \\mach\dirs\ONE\FurtherRubbish\blah\Extracted ROOT: \\mach\dirs\ONE\FurtherRubbish\blah2\Extracted\Stuff_1 ... WTF? Why wasn't \\mach\dirs\ONE removed? It clearly doesn't start with "keep_".

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• Why two subprocesses created by Java behave differently?

  - by Lily

  I use Java Runtime.getRuntime().exec(command) to create a subprocess and print its pid as follows: public static void main(String[] args) { Process p2; try { p2 = Runtime.getRuntime().exec(cmd); Field f2 = p2.getClass().getDeclaredField("pid"); f2.setAccessible(true); System.out.println( f2.get( p2 ) ); } catch (Exception ie) { System.out.println("Yikes, you are not supposed to be here"); } } I tried both C++ executable and Java executable (.jar file). Both executables will continuously print out "Hello World" to stdout. When cmd is the C++ executable, the pid is printed out to console but the subprocess gets killed as soon as main() returns. However, when I call the .jar executable in cmd, the subprocess does not get killed, which is the desired behavior. I don't understand why same Java code, with different executables can behave so differently. How should I modify my code so that I could have persistent subprocesses in Java. Newbie in this field. Any suggestion is welcomed. Lily

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• Inconsistent table width when hideing/showing a set of columns

  - by Salman A. Kagzi

  I have got a an HTML table of around 40+ columns. To make this table fit in the screen and have the data in a re presentable format we have section in this table. i.e. there are some column that are always visible and the remainder a made visible when s specific radio button (describing a section) is selected. Each radio button is associated to different number of columns. We show/hide a column by setting/removing "display:none" style in all the cell under that column. This all works Just fine. Now the real problem is with the width of the columns in this table. I cant use fixed with with pixel settings. I have tried using the percentage setting by giving 50% to the always visible part and rest 50% is divided between the column in a section. But I am unable to get a fixed behavior i.e. the size of the table columns across IE & FF. Some columns are just right while some are really huge. How can I get the table to give consistent column width across browsers?

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