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• Can't diagnose my MySQL root user problem

  - by George Crawford

  Hi all, I have a problem with the MySQL root user in My MySQL setup, and I just can't for the life of me work out how to fix it. It seems that I have somehow messed up the root user, and my access to databases is now very erratic. For reference, I'm using MAMP on OS X to provide the MySQL server. I'm not sure how much that matters though - I'd guess that whatever I've done will require a command-line fix to solve it. I can start MySQL using MAMP as usual, and access databases using the 'standard' users I have created for my PHP apps. However, the root user, which I use in my MySQL GUI client, and also in phpMyAdmin, can only access the "information_schema" database, as well as two I have created manually, and presumably (and mistakenly) left permissions wide open for. My 15 or so other databases cannot be accessed my the root user. When I load up phpMyAdmin, the home screen says: "Create new database: No Privileges". I certainly did at some stage change my root user's password using the MAMP dialog. But I don't remember if I did anything else which might have caused this problem. I've tried changing the password again, and there seems to be no change in the issue. I've also tried resetting root password using the command line, including starting mysql manually with --skip-grant-tables then flushing privs, but again, nothing seems to fix the issue. I've come to the end of my ideas, and would very much appreciate some step-by-step advice and diagnosis from one of the experts here! Many thanks for your help.

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• Xcode: Display Login View in applicationDidBecomeActive

  - by Patrick

  In my app I would like to show a login screen - which will be displayed when the app starts and when the app becomes active. For reference, I am using storyboards, ARC and it is a tabbed bar application. First off, I have this method which returns the topViewController. - (UIViewController *)topViewController:(UIViewController *)rootViewController { if (rootViewController.presentedViewController == nil) { return rootViewController; } if ([rootViewController.presentedViewController isMemberOfClass:[UINavigationController class]]) { UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController; UIViewController *lastViewController = [[navigationController viewControllers] lastObject]; return [self topViewController:lastViewController]; } UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController; return [self topViewController:presentedViewController]; } And I call this method here: - (void)applicationDidBecomeActive:(UIApplication *)application { if ( ... ) { // if the user needs to login PasswordViewController *passwordView = [[PasswordViewController alloc] init]; UIViewController *myView = [self topViewController:self.window.rootViewController]; [myView presentModalViewController:passwordView animated:NO]; } } To an extent this does work - I can call a method in viewDidAppear which shows an alert view to allow the user to log in. However, this is undesirable and I would like to have a login text box and other ui elements. If I do not call my login method, nothing happens and the screen stays black, even though I have put a label and other elements on the view. Does anyone know a way to resolve this? My passcode view is embedded in a Navigation Controller, but is detached from the main storyboard.

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• Can we manipulate (subtract) the value of a property while template bidning?

  - by Subhen

  Hi, I am currently defining few grids as following: <Grid.RowDefinitions> <RowDefinition Height="{TemplateBinding Height-Height/5}"/> <RowDefinition Height="{TemplateBinding Height/15}"/> <RowDefinition Height="{TemplateBinding Height/20}"/> <RowDefinition Height="{TemplateBinding Height/6}"/> </Grid.RowDefinitions> While the division works fine , the subtraction isn't yielding the output. Ialso tried like following: <RowDefinition Height="{TemplateBinding Height-(Height/5)}"/> Still no result. Any suggestions plz. Thanks, Subhen ** Update ** Now In My XAML I tried implementing the IvalueConverter like : <RowDefinition Height="{TemplateBinding Height, Converter={StaticResource heightConverter}}"/> Added the reference as <local:medieElementHeight x:Key="heightConverter"/> In side generic.cs I have coded as following: public class medieElementHeight : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { //customVideoControl objVdeoCntrl=new customVideoControl(); double custoMediaElementHeight = (double)value;//objVdeoCntrl.customMediaPlayer.Height; double mediaElementHeight = custoMediaElementHeight - (custoMediaElementHeight / 5); return mediaElementHeight; } #region IValueConverter Members object IValueConverter.ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } #endregion } But getting the exception Unknown Element Height in the element RowDefination.

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• Travelling Visual Studio developers

  - by Graphain

  Hi, I am about to travel to Europe (I'm Australian but imagine this is a similar circumstance for US users and simply flipped for European users). However, there is the slim possibility I will need to do some Visual Studio work while I'm travelling. As I see it I have three options: Leave a desktop PC on at home, access remotely via net cafes. Carry a laptop with me on the trip, upload files as required using public wifi. Option 2 but instead buy cheap light netbook that is miraculously capable of running VS. Does anyone have any experience or advice to shed on any of these options? For reference, this existing post suggests that VS remotely for short distances is okay, but over longer distances could be more problematic. I've used VS via RDP to a US server before and it was pretty laggy but for small changes I could get by. Concerns I have that you may have some experience with: Weight of luggage (ideally like to travel light) Security of laptop (imagine it'll be too heavy to carry around all the time so have to leave it at hotel/hostel etc. and hope for the best) Security of data (don't want someone stealing RDP access to my home PC) Security of FTP (don't want someone stealing FTP passwords over wireless)

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• Creation of Objects: Constructors or Static Factory Methods

  - by Rachel

  I am going through Effective Java and some of my things which I consider as standard are not suggested by the book, for instance creation of object, I was under the impression that constructors are the best way of doing it and books says we should make use of static factory methods, I am not able to few some advantages and so disadvantages and so am asking this question, here are the benefits of using it. Advantages: One advantage of static factory methods is that, unlike constructors, they have names. A second advantage of static factory methods is that, unlike constructors, they are not required to create a new object each time they’re invoked. A third advantage of static factory methods is that, unlike constructors, they can return an object of any subtype of their return type. A fourth advantage of static factory methods is that they reduce the verbosity of creating parameterized type instances. I am not able to understand this advantage and would appreciate if someone can explain this point Disadvantages: The main disadvantage of providing only static factory methods is that classes without public or protected constructors cannot be subclassed. A second disadvantage of static factory methods is that they are not readily distinguishable from other static methods.I am not getting this point and so would really appreciate some explanation. Reference: Effective Java, Joshua Bloch, Edition 2, pg: 5-10 Also, How to decide to use whether to go for Constructor or Static Factory Method for Object Creation ?

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• jQuery: one-liner for removing all children but one

  - by user1352530

  HTML code is: <li> <a href="#" /> <ul> <li> <a href="#"/> </li> </ul> </li> I want to delete any node under $(this) = li that is not a link. If there are more than one link, just the first one is saved, and if there are links inside the ul tag, they are not included because they are descendants and no childrens. Something like this (I am cloning and outputting html): $(this).clone().remove('not(a:first)').html(); //Assuming remove looks for "a" as a first child Does not work, so I try with this: $(this).clone().children().remove('not(a:first)').parent().html(); Does not work so I try with this: $(this).clone().remove('not(>a:first)').html(); I need the original element as a reference after removal for chaining more operations EDIT: Ok! Second one works with a little syntax correction as some appointed (:not( instead of not() but I would like to know if there is any other solution similar to the third line so I don't have to do children().remove().parent(). Thank you!

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• What does it mean to pass a &variable to a function? E.g., string& insert ( size_t pos1, const strin

  - by Bob Montgomery

  I understand passing a pointer, and returning a pointer: char * strcat ( char * destination, const char * source ); You're passing a variable that contains the address to a char; returning the same. But what does it mean to pass something using the reference operator? Or to return it? string& insert ( size_t pos1, const string& str ); I mean, I understand what actually happens, I just don't understand the notation. Why isn't the notation this instead: string * insert ( size_t pos1, const string * str ); //made up I presume it has something to do with passing/returning the instance of a class, but what? Is this syntax valid; if not why not and if so what does it mean? char & strcat ( char & destination, const char & source ); //made up (all of the function declarations, except the last made-up two, are from http://www.cplusplus.com )

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• adding a token onto a webservice or wcf call

  - by duncanUK

  I have an httphandler which I am using to log the http soap request and response for each webservice that is called from my application as a comms log. i would like to inject a token ont he 1st call (possibly the 1st call to invoke the service that is being logged) and then be able to track all subsequent webservice calls run in the same context with this token so i can tie the subsequent calls back up to the original call. so for example. main webservice -> 2nd web service -> another web service [token] [token] [token] -> nth web service [token] I would like to inject the token on the first call to the main webservice (http handler checks if no token, add it), I would like to use the same http handler to intercept each call to the subsequent webservices and pass on the token if it exists already (the job of the httphandler is to log the in/out soap with the token to reference with. I have managed to inject the first token, but my problem is how do I add the token on the subsequent calls.. can I make it stick on the same context or session? My worry is that when we call a new webservice, we create a whole new proxy/http request which will not inhrit the token... or will it?! Ideally I would like it to persist on the http header as I am setting the token as a header at the moment? has anyone got any ideas or a better way of doing this? I would be most greatful for you comments!

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• Compiling a C++ application on Windows 7, but execute it on Win2003 Server

  - by dabs

  I have a C++ application (quite complex, multiple projects) in Visual Studio 2008, that produces a single dll. Recently I switched to Windows 7, but had previously been compiling under Windows XP. Suddenly the dll in question cannot be loaded by another application, i.e. on a machine running Windows 2003 Server. I've been trying various things: I've installed the VC9.0 redistributable package on the server Also copied various .dll's from that package to the application folder The project is of course compiled in release mode When I run depends.exe on the client machine, I do get the following error: "Error: The Side-by-Side configuration information for "my_dll.dll" contains errors. This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem (14001). Warning: At least one module has an unresolved import due to a missing export function in a delay-load dependent module." and the icon for shlwapi.dll has a red overlay icon. This didn't happen when I was compiling under WinXP, so I'm guessing that there really is no problem with the .dll's on the client machine, but somewhere there is a reference to that particular version of some dll. Does anyone know what would be the best way to resolve this? Regards, Daníel

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• Accessing global variables of custom controls in ASP.NET

  - by CL4NCY

  Hi, I have built lots of custom asp.net controls which work really well separately but I want to somehow allow global access to all their variables from anywhere on the page. I have a central control called the ContentManager which I can use to store these variables. The problem I have is that all the controls are bound at different times so I only want the variables available after they're bound. For example I have many custom repeaters on the page which when bound I want to add a reference in the content manager so all their variables are then available to use. <Custom:ContentManager ID="cm" runat="server"/> <Custom:Repeater ID="r1" runat="server"/> <Custom:Repeater ID="r2" runat="server"/> <Custom:Repeater ID="r3" runat="server"/> Then I want a tag which can access all variables from any of these controls. <%= cm.controls["r1"].Items[0]["name"] %> The problem with this is that the variable isn't available until the repeater is bound so I might need to use events to push out the value to tags on the page like so: <Custom:Var ID="v1" control="r1" value="Items[0]["name"]" runat="server"/> Is this possible or can you recommend a better approach?

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• MySQL " identify storage engine statement"

  - by sammysmall

  This IS NOT a Homework question! While building my current student database project I realized that I may want to identify comprehensive information about a database design in the future. More-so if I am fortunate enough to get a job in this field and were handed a database project how could I break down certain elements for identification... In all of my previous designs I have been using MySQL Community Server (GPL) 5.1.42, I thought (duh) that I was using the MyISAM based on most of my text-book instruction and MySQL 5.0 Reference Manual :: 13 Storage Engines :: 13.1 The MyISAM Storage Engine I determined that this was in fact incorrect for this version and the use of "SHOW ENGINES" at the console... No problem, figured out why they have "versions" the need to pay attention to what version is being used, and the need for a means to determine what I am about to mess up "if" I do not pay attention to detail... Q1. Specifically what statement will identify the version used by someone elses initial database creation? (since I created my own databases I know what version I used) Q2. Specifically what statement will identify the storage engine that the developer used when creating the database. (I specified a particular database in my collection then tried SHOW Engine, did not work, then tried to just get the metadata from one table in that database: mysql SELECT duck_cust, table_type, engine - FROM INFORMATION_SCHEMA.tables - WHERE table_schema = 'tp' - ORDER BY table_type ASC, table_name DESC; as this was not really what I wanted (and did not work) I am looking for some direction from the pros... Q3. (If you really have the inclination to continue helping) If I were to access a database from an earlier/later "version" are there backward/forward compatibility issues for maintaining/updating data between versions? Please and Thank you in advance for your time and efforts! sammysmall

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• Java downcasting dilemma

  - by Shades88

  please have a look at this code here. class Vehicle { public void printSound() { System.out.print("vehicle"); } } class Car extends Vehicle { public void printSound() { System.out.print("car"); } } class Bike extends Vehicle{ public void printSound() { System.out.print("bike"); } } public class Test { public static void main(String[] args) { Vehicle v = new Car(); Bike b = (Bike)v; v.printSound(); b.printSound(); Object myObj = new String[]{"one", "two", "three"}; for (String s : (String[])myObj) System.out.print(s + "."); } } Executing this code will give ClassCastException saying inheritance.Car cannot be cast to inheritance.Bike. Now look at the line Object myObj = new String[]{"one", "two", "three"};. This line is same as Vehicle v = new Car(); right? In both lines we are assigning sub class object to super class reference variable. But downcasting String[]myObj is allowed but (Bike)v is not. Please help me understand what is going on around here.

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• InvalidOperationException: The Undo operation encountered a context that is different from what was

  - by McN

  I got the following exception: Exception Type: System.InvalidOperationException Exception Message: The Undo operation encountered a context that is different from what was applied in the corresponding Set operation. The possible cause is that a context was Set on the thread and not reverted(undone). Exception Stack: at System.Threading.SynchronizationContextSwitcher.Undo() at System.Threading.ExecutionContextSwitcher.Undo() at System.Threading.ExecutionContext.runFinallyCode(Object userData, Boolean exceptionThrown) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteBackoutCodeHelper(Object backoutCode, Object userData, Boolean exceptionThrown) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Net.ContextAwareResult.Complete(IntPtr userToken) at System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken) at System.Net.Sockets.BaseOverlappedAsyncResult.CompletionPortCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) Exception Source: mscorlib Exception TargetSite.Name: Undo Exception HelpLink: The application is a Visual Studio 2005 (.Net 2.0) console application. It is a server for multiple TCP/IP connections, doing asynchronous socket reads and synchronous socket writes. In searching for an answer I came across this post which talks about a call to Application.Doevents() which I don't use in my code. I also found this post which has a resolution involved with Component which I also don't use in my code. The application does reference a library that I created that contains custom user controls and components, but they are not being used by the application. Question: What caused this to happen and how do I prevent this from happening again? Or a more realistic question: What does this exception actually mean? How is "context" defined in this situation? Anything that can help me understand what is going on would be very much appreciated.

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• How To Deal With Exceptions In Large Code Bases

  - by peter

  Hi All, I have a large C# code base. It seems quite buggy at times, and I was wondering if there is a quick way to improve finding and diagnosing issues that are occuring on client PCs. The most pressing issue is that exceptions occur in the software, are caught, and even reported through to me. The problem is that by the time they are caught the original cause of the exception is lost. I.e. If an exception was caught in a specific method, but that method calls 20 other methods, and those methods each call 20 other methods. You get the picture, a null reference exception is impossible to figure out, especially if it occured on a client machine. I have currently found some places where I think errors are more likely to occur and wrapped these directly in their own try catch blocks. Is that the only solution? I could be here a long time. I don't care that the exception will bring down the current process (it is just a thread anyway - not the main application), but I care that the exceptions come back and don't help with troubleshooting. Any ideas? I am well aware that I am probably asking a question which sounds silly, and may not have a straightforward answer. All the same some discussion would be good.

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• A typical mysql query( how to use subquery column into main query)

  - by I Like PHP

  I HAVE TWO TABLES shown below table_joining id join_id(PK) transfer_id(FK) unit_id transfer_date joining_date 1 j_1 t_1 u_1 2010-06-05 2010-03-05 2 j_2 t_2 u_3 2010-05-10 2010-03-10 3 j_3 t_3 u_6 2010-04-10 2010-01-01 4 j_5 NULL u_3 NULL 2010-06-05 5 j_6 NULL u_4 NULL 2010-05-05 table_transfer id transfer_id(PK) pastUnitId futureUnitId effective_transfer_date 1 t_1 u_3 u_1 2010-06-05 2 t_2 u_6 u_1 2010-05-10 3 t_3 u_5 u_3 2010-04-10 now i want to know total employee detalis( using join_id) which are currently working on unit u_3 . means i want only join_id j_1 (has transfered but effective_transfer_date is future date, right now in u_3) j_2 ( tansfered and right now in `u_3` bcoz effective_transfer_date has been passed) j_6 ( right now in `u_3` and never transfered) what i need to take care of below steps( as far as i know ) <1> first need to check from table_joining whether transfer_id is NULL or not <2> if transfer_id= is NULL then see unit_id=u_3 where joining_date <=CURDATE() ( means that person already joined u_3) <3> if transfer_id is NOT NULL then go to table_transfer using transfer_id (foreign key reference) <4> now see the effective_transfer_date regrading that transfer_id whether effective_transfer_date<=CURDATE() <5> if transfer date has been passed(means transfer has been done) then return futureUnitID otherwise return pastUnitID i used two separate query but don't know how to join those query?? for step <1 ans <2 SELECT unit_id FROM table_joining WHERE joining_date<=CURDATE() AND transfer_id IS NULL AND unit_id='u_3' for step<5 SELECT IF(effective_transfer_date <= CURDATE(),futureUnitId,pastUnitId) AS currentUnitID FROM table_transfer // here how do we select only those rows which have currentUnitID='u_3' ?? please guide me the process?? i m just confused with JOINS. i think using LEFT JOIN can return the data i need, or if we use subquery value to main query? but i m not getting how to implement ...please help me. Thanks for helping me alwayz

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• dynamic LinkButton OnClick event not working on ASP.Net

  - by user1004472

  I want to create dynamic LinkButton for image, <img> tag is not working dynamically so I am using LinkButton with image. I don't want to provide ID to LinkButton because I want to generate more LinkButton dynamically. I am using following code in Default.aspx <%@ Page Language="C#"%> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <script runat="server"> protected void Page_Load(object sender, EventArgs e) { Response.Write(@"<asp:LinkButton runat=""server"" OnClick=""btn_click""><img src=""close-icon (1).png"" /></asp:LinkButton>"); } public void btn_click(object sender, EventArgs e) { Response.Write("HELLO"); } </script> </head> <body> <form id="form1" runat="server"> <div> </div> </form> </body> </html> I also tried to write tag code in Default.aspx.cs file but not work. It's showing me following error. Error 1 'ASP.default_aspx' does not contain a definition for 'img_Click' and no extension method 'img_Click' accepting a first argument of type 'ASP.default_aspx' could be found (are you missing a using directive or an assembly reference?) Please help me to solve this problem.

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• Presenting collection of structures of strings in grid or similar in WPF - Example? Ideas?

  - by Andrew

  Hi, I have a collection of structures. The structure is just some strings. Example public struct ReportLine { public string Name; public string Address; public string Phone; ...// about 10 other strings } I can't change this part. What I want to do is display it in a simple grid or simlar in WPF. My only requirements are: a) need column headers b) rows must alternate in color c) columns big enough to hold largest datum (which is not know until run time) Can someone point me to an example to get me started? Is the GridView the way to go? Or DataGrid? Or perhaps just the grid? I have the book Pro WPF in C# 2008 and it covers binding ListBox's to collections, but the collections always seem to be collections of one field (ex. a collection of 40 names). Here I have a collection (an array in fact) of a structure. How do I setup the databinding? As you can see, I'm new to this and probably would most benefit from a reference to an article. I've found articles covering collections of 1 field, but no examples covering binding to an array of structures. Also, my intitial research indicates c) can't be easily done, if you demand that the column is big enough for all the data in that column, not just the visible data. Thanks, dave

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• Referencing not-yet-defined variables - Java

  - by user2537337

  Because I'm tired of solving math problems, I decided to try something more engaging with my very rusty (and even without the rust, very basic) Java skills. I landed on a super-simple people simulator, and thus far have been having a grand time working through the various steps of getting it to function. Currently, it generates an array of people-class objects and runs a for loop to cycle through a set of actions that alter the relationships between them, which I have stored in a 2d integer array. When it ends, I go look at how much they all hate each other. Fun stuff. Trouble has arisen, however, because I would like the program to clearly print what action is happening when it happens. I thought the best way to do this would be to add a string, description, to my "action" class (which stores variables for the actor, reactor, and the amount the relationship changes). This works to a degree, in that I can print a generic message ("A fight has occurred!") with no problem. However, ideally I would like it to be a little more specific ("Person A has thrown a rock at Person B's head!"). This latter goal is proving more difficult: attempting to construct an action with a description string that references actor and reactor gets me a big old error, "Cannot reference field before it is defined." Which makes perfect sense. I believe I'm not quite in programmer mode, because the only other way I can think to do this is an unwieldy switch statement that negates the need for each action to have its own nicely-packaged description. And there must be a neater way. I am not looking for examples of code, only a push in the direction of the right concept to handle this.

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• What is a reasonable OSGi development workflow?

  - by levand

  I'm using OSGi for my latest project at work, and it's pretty beautiful as far as modularity and functionality. But I'm not happy with the development workflow. Eventually, I plan to have 30-50 separate bundles, arranged in a dependency graph - supposedly, this is what OSGi is designed for. But I can't figure out a clean way to manage dependencies at compile time. Example: You have bundles A and B. B depends on packages defined in A. Each bundle is developed as a separate Java project. In order to compile B, A has to be on the javac classpath. Do you: Reference the file system location of project A in B's build script? Build A and throw the jar into B's lib directory? Rely on Eclipse's "referenced projects" feature and always use Eclipse's classpath to build (ugh) Use a common "lib" directory for all projects and dump the bundle jars there after compilation? Set up a bundle repository, parse the manifest from the build script and pull down the required bundles from the repository? No. 5 sounds the cleanest, but also like a lot of overhead.

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• Cant insert a object into a silverlight databound combo box

  - by Steve

  Hi Until recently I had a combo box that was bound to a Linq queried IEnumerable of a DataService.Obj type in the bind method, and all worked fine private IEnumerable<DataService.Obj> _GeneralList; private IEnumerable<DataService.Obj> _QueriedList; private void Bind() { _GeneralList = SharedLists.GeneralList; _QueriedList = _GeneralList.Where(q =>q.ID >1000); cmbobox.ItemsSource = _QueriedList; } Then I had to change the method to insert a new obj and set that object as the default obj and now I get a "System.NullReferenceException: Object reference not set to an instance of an object" exception. I know this has to do with inserting into a linq queried ienumerable but I cant fix it. Any help will be gratefully received. private IEnumerable<DataService.Obj> _GeneralList; private IEnumerable<DataService.Obj> _QueriedList; private void Bind() { _GeneralList = SharedLists.GeneralList; _QueriedList = _GeneralList.Where(q =>q.ID >1000); cmbobox.ItemsSource = _QueriedList; DataService.Obj info = new DataService.Obj(); info.ID = "0"; (cmbobox.ItemsSource as ObservableCollection<DataService.Obj>).Insert(0,info); cmbobox.SelectedIndex = 0; } Thanks in advance

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• JavaScript window object element properties

  - by Timothy

  A coworker showed me the following code and asked me why it worked. <span id="myspan">Do you like my hat?</span> <script type="text/javascript"> var spanElement = document.getElementById("myspan"); alert("Here I am! " + spanElement.innerHTML + "\n" + myspan.innerHTML); </script> I explained that a property is attached to the window object with the name of the element's id when the browser parses the document which then contains a reference to the appropriate dom node. It's sort of as if window.myspan = document.getElementById("myspan") is called behind the scenes as the page is being rendered. The ensuing discussion we had raised a few of questions: The window object and most of the DOM are not part of the official JavaScript/ECMA standards, but is the above behavior documented in any other official literature, perhaps browser-related? The above works in a browser (at least the main contenders) because there is a window object, but fails in something like rhino. Is writing code that relys on this considered bad practice because it makes too many assumptions about the execution environment? Are there any browsers in which the above would fail, or is this considered standard behavior across the board? Does anyone here know the answers to those questions and would be willing to enlighten me? I tried a quick internet search, but I admit I'm not sure how to even properly phrase the query. Pointers to references and documentation are welcome.

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• how to share a variable between two threads

  - by prmatta

  I just inherited some code, two threads within this code need to perform a system task. One thread should do the system task before the other thread. They should not be performing the system task together. The two threads do not have references to each other. Now, I know I can use some sort of a semaphore to achieve this. But my question is what is the right way to get both threads to access this semaphore. I could create a static variable/method a new class : public class SharedSemaphore { private static Semaphore s = new Semaphore (1, true); public static void performSystemTask () { s.acquire(); } public static void donePerformingSystemTask() { s.release(); } } This would work (right?) but this doesn't seem like the right thing to do. Because, the threads now have access to a semaphore, without ever having a reference to it. This sort of thing doesn't seem like a good programming practice. Am I wrong?

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• How do I override a python import?

  - by Evan Plaice

  So I'm working on pypreprocessor which is a preprocessor that takes c-style directives and I've been able to make it work like a traditional preprocessor (it's self-consuming and executes postprocessed code on-the-fly) except that it breaks library imports. The problem is. The preprocessor runs through the file, processes' it, outputs to a temp file, and exec() the temp file. Libraries that are imported need to be handled a little different because they aren't executed but rather loaded and made accessible to the caller module. What I need to be able to do is. Interrupt the import (since the preprocessor is being run in the middle of the import), load the postprocessed code as a tempModule, and replace the original import with the tempModule to trick the calling script with the import into believing that the tempModule is the original module. I have searched everywhere and so far, have no solution. This question is the closest I've seen so far to providing an answer: http://stackoverflow.com/questions/1096216/override-namespace-in-python Here's what I have. # remove the bytecode file created by the first import os.remove(moduleName + '.pyc') # remove the first import del sys.modules[moduleName] # import the postprocessed module tmpModule = __import__(tmpModuleName) # set first module's reference to point to the preprocessed module sys.modules[moduleName] = tmpModule moduleName is the name of the original module, tmpModuleName is the name of the postprocessed code file. The strange part is, this solution still runs completely normal as if the first module completed loaded normally; unless you remove the last line, then you get a module not found error. Hopefully someone on SO know a lot more about imports than I do because this one has me stumped.

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• Very very weird problem with UIImageView property - I can access it then I can't, and it's not nil.

  - by just_another_coder

  Very very weird problem with UIImageView property on iPad application @interface MyViewController : UIViewController { IBOutlet UIImageView* coverImage; } @property(nonatomic, retain) IBOutlet UIImageView* coverImage; … more code @implementation MyViewController @synthesize coverImage; … more code - (void)viewDidLoad { [super viewDidLoad]; NSString* imageName = @"my_image.png"; UIImage* tempImage = [UIImage imageNamed:imageName]; [self.coverImage setImage:tempImage]; } The above code WILL display the image. In another part of code: -(IBAction) stopButtonPressed:(id)sender { [self.coverImage setHidden:YES]; NSLog(@"coverImage desc: %@", [coverImage description]); } The image will NOT disappear. I know the reference to the image isn't nil, because it gives me this output: 2010-05-29 17:37:40.706 MyApp[95360:207] coverImage desc: UIImageView: 0x5128420; frame = (0 0; 1024 768); autoresize = RM+BM; userInteractionEnabled = NO; layer = CALayer: 0x512bed0 In addition, if I move the code in viewDidLoad to another part of the class, and try to execute it from there, it fails to show the image at all.

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• How to pass data to a C++0x lambda function that will run in a different thread?

  - by Dimitri C.

  In our company we've written a library function to call a function asynchronously in a separate thread. It works using a combination of inheritance and template magic. The client code looks as follows: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, &DemoThread::SomeFunction, stringToPassByValue); Since the introduction of lambda functions I'd like to use it in combination with lambda functions. I'd like to write the following client code: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, [=]() { const std::string someCopy = stringToPassByValue; }); Now, with the Visual C++ 2010 this code doesn't work. What happens is that the stringToPassByValue is not copied. Instead the "capture by value" feature passes the data by reference. The result is that if the function is executed after stringToPassByValue has gone out of scope, the application crashes as its destructor is called already. So I wonder: is it possible to pass data to a lambda function as a copy? Note: One possible solution would be to modify our framework to pass the data in the lambda parameter declaration list, as follows: DemoThread thread; std::string stringToPassByValue = "The string to pass by value"; AsyncCall(thread, [=](const std::string stringPassedByValue) { const std::string someCopy = stringPassedByValue; } , stringToPassByValue); However, this solution is so verbose that our original function pointer solution is both shorter and easier to read. Update: The full implementation of AsyncCall is too big to post here. In short, what happens is that the AsyncCall template function instantiates a template class holding the lambda function. This class is derived from a base class that contains a virtual Execute() function, and upon an AsyncCall() call, the function call class is put on a call queue. A different thread then executes the queued calls by calling the virtual Execute() function, which is polymorphically dispatched to the template class which then executes the lambda function.

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