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  • error C2512 in precompiled header file?

    - by SoloMael
    I'm having a ridiculously strange problem. When I try to run the program below, there's an error message that says: "error C2512: 'Record' : no appropriate default constructor available". And when I double-click it, it directs me to a precompiled read-only header file named "xmemory0". Do they expect me to change a read-only file? Here's the segment of code in the file it directs me to: void construct(_Ty *_Ptr) { // default construct object at _Ptr ::new ((void *)_Ptr) _Ty(); // directs me to this line } Here's the program: #include <iostream> #include <vector> #include <string> using namespace std; const int NG = 4; // number of scores struct Record { string name; // student name int scores[NG]; double average; // Calculate the average // when the scores are known Record(int s[], double a) { double sum = 0; for(int count = 0; count != NG; count++) { scores[count] = s[count]; sum += scores[count]; } average = a; average = sum / NG; } }; int main() { // Names of the class string names[] = {"Amy Adams", "Bob Barr", "Carla Carr", "Dan Dobbs", "Elena Evans"}; // exam scores according to each student int exams[][NG]= { {98, 87, 93, 88}, {78, 86, 82, 91}, {66, 71, 85, 94}, {72, 63, 77, 69}, {91, 83, 76, 60}}; vector<Record> records(5); return 0; }

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  • Dependency injection and factory

    - by legenden
    Trying to figure out how to best handle the following scenario: Assume a RequestContext class which has a dependency to an external service, such as: public class RequestContext : IRequestContext { private readonly ServiceFactory<IWeatherService> _weatherService; public RequestContext(ServiceFactory<IWeatherService> weatherService, UserLocation location, string query) { _weatherService = weatherService; ... What sort of dependency should I require in the class that will ultimately instantiate RequestContext? It could be ServiceFactory<IWeatherService>, but that doesn't seem right, or I could create an IRequestContextFactory for it along the lines of: public class RequestContextFactory : IRequestContextFactory { private readonly ServiceFactory<IWeatherService> _weatherService; public RequestContextFactory(ServiceFactory<IWeatherService> weatherService) { _weatherService = weatherService; } public RequestContext Create(UserLocation location, string query) { return new RequestContext(_weatherService, location, query); } } And then pass the IRequestContextFactory through constructor injection. This seems like a good way to do it, but the problem with this approach is that I think it hinders discoverability (devs must know about the factory and implement it, which is not really apparent). Is there a better/more discoverable way that I'm missing?

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  • Translate SQL to OCL ?

    - by Roland Bengtsson
    I have a piece of SQL that I want to translate to OCL. I'm not good at SQL so I want to increase maintainability by this. We are using Interbase 2009, Delphi 2007 with Bold and modeldriven development. Now my hope is that someone here both speaks good SQL and OCL :-) The original SQL: Select Bold_Id, MessageId, ScaniaId, MessageType, MessageTime, Cancellation, ChassieNumber, UserFriendlyFormat, ReceivingOwner, Invalidated, InvalidationReason, (Select Parcel.MCurrentStates From Parcel Where ScaniaEdiSolMessage.ReceivingOwner = Parcel.Bold_Id) as ParcelState From ScaniaEdiSolMessage Where MessageType = 'IFTMBP' and not Exists (Select * From ScaniaEdiSolMessage EdiSolMsg Where EdiSolMsg.ChassieNumber = ScaniaEdiSolMessage.ChassieNumber and EdiSolMsg.ShipFromFinland = ScaniaEdiSolMessage.ShipFromFinland and EdiSolMsg.MessageType = 'IFTMBF') and invalidated = 0 Order By MessageTime desc After a small simplification: Select Bold_Id, (Select Parcel.MCurrentStates From Parcel where ScaniaEdiSolMessage.ReceivingOwner = Parcel.Bold_Id) From ScaniaEdiSolMessage Where MessageType = 'IFTMBP' and not Exists (Select * From ScaniaEdiSolMessage EdiSolMsg Where EdiSolMsg.ChassieNumber = ScaniaEdiSolMessage.ChassieNumber and EdiSolMsg.ShipFromFinland = ScaniaEdiSolMessage.ShipFromFinland and EdiSolMsg.MessageType = 'IFTMBF') and invalidated = 0 NOTE: There are 2 cases for MessageType, 'IFTMBP' and 'IFTMBF'. So the table to be listed is ScaniaEdiSolMessage. It has attributes like: MessageType: String ChassiNumber: String ShipFromFinland: Boolean Invalidated: Boolean It has also a link to table Parcel named ReceivingOwner with BoldId as key. So it seems like it list all rows of ScaniaEdiSolMessage and then have a subquery that also list all rows of ScaniaEdiSolMessage and name it EdiSolMsg. The it exclude almost all rows. In fact the query above give one hit from 28000 records. In OCL it is easy to list all instances: ScaniaEdiSolMessage.allinstances Also easy to filter rows by select for example: ScaniaEdiSolMessage.allinstances->select(shipFromFinland and not invalidated) But I do not understand how I should make a OCL to match the SQL above.

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  • DBD::CSV: Problem with file-name-extensions

    - by sid_com
    In this script I have problems with file-name-extensions: if I use /home/mm/test_x it works, with file named /home/mm/test_x.csv it doesn't: #!/usr/bin/env perl use warnings; use strict; use 5.012; use DBI; my $table_1 = '/home/mm/test_1.csv'; my $table_2 = '/home/mm/test_2.csv'; #$table_1 = '/home/mm/test_1'; #$table_2 = '/home/mm/test_2'; my $dbh = DBI->connect( "DBI:CSV:" ); $dbh->{RaiseError} = 1; $table_1 = $dbh->quote_identifier( $table_1 ); $table_2 = $dbh->quote_identifier( $table_2 ); my $sth = $dbh->prepare( "SELECT a.id, a.name, b.city FROM $table_1 AS a NATURAL JOIN $table_2 AS b" ); $sth->execute; $sth->dump_results; $dbh->disconnect; Output with file-name-extention: DBD::CSV::st execute failed: Execution ERROR: No such column '"/home/mm/test_1.csv".id' called from /usr/local/lib/perl5/site_perl/5.12.0/x86_64-linux/DBD/File.pm at 570. Output without file-name-extension: '1', 'Brown', 'Laramie' '2', 'Smith', 'Watertown' 2 rows Is this a bug?

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  • Calling PHP functions within HEREDOC strings

    - by Doug Kavendek
    In PHP, the HEREDOC string declarations are really useful for outputting a block of html. You can have it parse in variables just by prefixing them with $, but for more complicated syntax (like $var[2][3]), you have to put your expression inside {} braces. In PHP 5, it is possible to actually make function calls within {} braces inside a HEREDOC string, but you have to go through a bit of work. The function name itself has to be stored in a variable, and you have to call it like it is a dynamically-named function. For example: $fn = 'testfunction'; function testfunction() { return 'ok'; } $string = <<< heredoc plain text and now a function: {$fn()} heredoc; As you can see, this is a bit more messy than just: $string = <<< heredoc plain text and now a function: {testfunction()} heredoc; There are other ways besides the first code example, such as breaking out of the HEREDOC to call the function, or reversing the issue and doing something like: ?> <!-- directly outputting html and only breaking into php for the function --> plain text and now a function: <?PHP print testfunction(); ?> The latter has the disadvantage that the output is directly put into the output stream (unless I'm using output buffering), which might not be what I want. So, the essence of my question is: is there a more elegant way to approach this? Edit based on responses: It certainly does seem like some kind of template engine would make my life much easier, but it would require me basically invert my usual PHP style. Not that that's a bad thing, but it explains my inertia.. I'm up for figuring out ways to make life easier though, so I'm looking into templates now.

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  • Core data setReturnsDistinctResult not working

    - by Moze
    So i'm building a small application, it uses core data database of ~25mb size with 4 entities. It's for bus timetables. In one table named "Stop" there are have ~1300 entries of bus stops with atributes "name", "id", "longitude", "latitude" and couple relationships. Now there are many stops with same name but different coordinates and id. Search is implemented using NSPredicate. So I want to show all distinct stop names in table view, i'm using setReturnsDistinctResults with NSDictionaryResultType and setPropertiesToFetch. But setReturnsDistinctResult is not working and I'm still getting all entries. Heres code: - (NSFetchRequest *)fetchRequest { if (fetchRequest == nil) { fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Stop" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSArray *sortDescriptors = [NSArray arrayWithObject:[[[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES] autorelease]]; [fetchRequest setSortDescriptors:sortDescriptors]; [fetchRequest setResultType:NSDictionaryResultType]; [fetchRequest setPropertiesToFetch:[NSArray arrayWithObject:[[entity propertiesByName] objectForKey:@"name"]]]; [fetchRequest setReturnsDistinctResults:YES]; DebugLog(@"fetchRequest initialized"); } return fetchRequest; } ///////////////////// - (NSFetchedResultsController *)fetchedResultsController { if (self.predicateString != nil) { self.predicate = [NSPredicate predicateWithFormat:@"name CONTAINS[cd] %@", self.predicateString]; [self.fetchRequest setPredicate:predicate]; } else { self.predicate = nil; [self.fetchRequest setPredicate:predicate]; } fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:self.fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:sectionNameKeyPath cacheName:nil]; return fetchedResultsController; } ////////////// - (UITableViewCell *)tableView:(UITableView *)table cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } cell.textLabel.text = [[fetchedResultsController objectAtIndexPath:indexPath] valueForKey:@"name"]; return cell; }

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  • Literal ampersands in System.Uri query string

    - by Nathan Baulch
    I'm working on a client app that uses a restful service to look up companies by name. It's important that I'm able to include literal ampersands in my queries since this character is quite common in company names. However whenever I pass %26 (the URI escaped ampersand character) to System.Uri, it converts it back to a regular ampersand character! On closer inspection, the only two characters that aren't converted back are hash (%23) and percent (%25). Lets say I want to search for a company named "Pierce & Pierce": var endPoint = "http://localhost/companies?where=Name eq '{0}'"; var name = "Pierce & Pierce"; Console.WriteLine(new Uri(string.Format(endPoint, name))); Console.WriteLine(new Uri(string.Format(endPoint, Uri.EscapeUriString(name)))); Console.WriteLine(new Uri(string.Format(endPoint, Uri.EscapeDataString(name)))); All three of the above combinations return: http://localhost/companies?where=Name eq 'Pierce & Pierce' This causes errors on the server side since the ampersand is (correctly) interpreted as a query arg delimiter. What I really need it to return is the original string: http://localhost/companies?where=Name eq 'Pierce %26 Pierce' How can I work around this behavior without discarding System.Uri entirely? I can't replace all ampersands with %26 at the last moment because there will usually be multiple query args involved and I don't want to destroy their delimiters. Note: A similar problem was discussed in this question but I'm specifically referring to System.Uri.

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  • Need Help with wxPython & pyGame

    - by Xavier
    Hi Guys, I'm actually in need of your help and advice here on my assignment that I am working on. First of all, I was task to do a program that runs langton's ant simulation. For that, I've managed to get the source code (from snippets.dzone.com/posts/show/5143) and edited it accordingly to my requirements. This was done and ran in pygame module extension. In addition, my task requires a GUI to interface for users to run and navigate through the screens effectively with the langton's ant program running. I used wxPython with the help of an IDE called BOA constructor to create the frames, buttons, textboxes, etc. Basically, all the stuff needed in the interfaces. However, I've ran into some problems listed below: Found problem integrating pyGame with wxPython. On this note, I've research the internet for answers and tutorials where I found out from website: wiki.wxpython.org/IntegratingPyGame & aspn.activestate.com/ASPN/Mail/Message/wxpython-users/3178042. I understand from the sites that integrating pyGame with wxPython will be a difficult task where it has caused common problems like the inability to placing other controls into the frames as the pyGame application will cover the entire panel. I really hope that you can clarify my doubts on this and advise me on the path that I should take from here. Therefore, I ask the following questions: Is it feasible to integrate pyGame with wxPython? If it is not feasible to integrate pyGame with wxPython, what other alternatives do I have to create a GUI interface integrating pyGame into it. If so how do I go about? If it is possible to go about integrating pyGame with wxPython, how do I go about doing so? Really need you guys opinion on this.

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  • What is the most efficient way to display decoded video frames in Qt?

    - by Jason
    What is the fastest way to display images to a Qt widget? I have decoded the video using libavformat and libavcodec, so I already have raw RGB or YCbCr 4:2:0 frames. I am currently using a QGraphicsView with a QGraphicsScene object containing a QGraphicsPixmapItem. I am currently getting the frame data into a QPixmap by using the QImage constructor from a memory buffer and converting it to QPixmap using QPixmap::fromImage(). I like the results of this and it seems relatively fast, but I can't help but think that there must be a more efficient way. I've also heard that the QImage to QPixmap conversion is expensive. I have implemented a solution that uses an SDL overlay on a widget, but I'd like to stay with just Qt since I am able to easily capture clicks and other user interaction with the video display using the QGraphicsView. I am doing any required video scaling or colorspace conversions with libswscale so I would just like to know if anyone has a more efficient way to display the image data after all processing has been performed. Thanks.

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  • Subclassing NSArrayController in order to limit size of arrangedObjects

    - by Simone Manganelli
    I'm trying to limit the number of objects in an array controller, but I still want to be able to access the full array, if necessary. A simple solution I came up with was to subclass NSArrayController, and define a new method named "limitedArrangedObjects", that returns a limited number of objects from the real set of arranged objects. (I've seen http://stackoverflow.com/questions/694493/limiting-the-number-of-objects-in-nsarraycontroller , but that doesn't address my problem.) I want this property to be observable via bindings, so I set a dependency to arrangedObjects on it. Problem is, when arrangedObjects is updated, limitedArrangedObjects seems not to be observing the value change in arrangedObjects. I've hooked up an NSCollectionView to limitedArrangedObjects, and zero objects are being displayed. (If I bind it to arrangedObjects instead, all the objects show up as expected.) What's the problem? Here's the relevant code: @property (readonly) NSArray *limitedArrangedObjects; - (NSArray *)limitedArrangedObjects; { NSArray *arrangedObjects = [super arrangedObjects]; NSUInteger upperLimit = 10000; NSUInteger count = [arrangedObjects count]; if (count > upperLimit) count = upperLimit; arrayToReturn = [arrangedObjects subarrayWithRange:NSMakeRange(0, count)]; return arrayToReturn; } + (NSSet *)keyPathsForValuesAffectingValueForKey:(NSString *)key; { NSSet *keyPaths = [super keyPathsForValuesAffectingValueForKey:key]; if ([key isEqualToString:@"limitedArrangedObjects"]) { NSSet *affectingKeys = [NSSet setWithObjects:@"arrangedObjects",nil]; keyPaths = [keyPaths setByAddingObjectsFromSet:affectingKeys]; } return keyPaths; }

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  • httpHandler - subfolder issue

    - by Patto
    Hi, I am trying to redirect my old typepad blog to my new blog (permanent 301 redirect) that runs with wordpress. The new blog will also be on a new server. the old Blog had the following structure: http://subdomain.domain.com/weblog/year/month/what-ever-article.html The new Blog looks like this: http://www.domain.com/Blog/year/month/what-ever-article.html I am using an http handler that I found online and tried to work with it: public class MyHttpModule :IHttpModule { public MyHttpModule() { // // TODO: Add constructor logic here // } #region IHttpModule Members public void Dispose() { } public void Init(HttpApplication context) { context.BeginRequest += new EventHandler(context_BeginRequest); } void context_BeginRequest(object sender, EventArgs e) { string oldURL = System.Web.HttpContext.Current.Request.Url.ToString(); string newURL = String.Empty; //oldURL = if (oldURL.ToString().ToLower().IndexOf("articles") >= 0 || System.Web.HttpContext.Current.Request.Url.ToString().ToLower().IndexOf("weblog") >= 0) { newURL = oldURL.Replace("subdomain.domain.com/weblog", "www.domain.com/Blog/index.php"); if (newURL.ToLower().Contains("subdomain")) { newURL = "http://www.domain.com/Blog"; } } else { newURL = "http://www.domain.com/Blog"; } System.Web.HttpContext.Current.Response.Clear(); System.Web.HttpContext.Current.Response.StatusCode = 301; System.Web.HttpContext.Current.Response.AddHeader("Location", newURL); System.Web.HttpContext.Current.Response.End(); } #endregion } To use this code, I put the handler into the web.config <httpModules> <add name="MyHttpModule" type="MyHttpModule, App_Code"/> </httpModules> The issue that I have is that when I want to redirect from the http://subdomain.domain.com/weblog/year/month/what-ever-article.html, I get an error that the folder would not exist. Is there any way to change my script or add an catch all to the web.config that forwards the URL to my script? When I use "http://subdomain.domain.com/weblog/year/month/what-ever-article.html" in oldURL string, then the redirect works just fine... so I must have some IIS or web.config settings wrong. Thanks in advance, Patrick

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  • Uncompress a TIFF file without going through BufferedImage

    - by Gert
    I am receiving large size CCITT Group 4 compressed TIFF files that need to be written elsewhere as uncompressed TIFF files. I am using the jai_imageio TIFF reader and writer to do that and it works well as long as the product _width * height_ of the image fits in an integer. Here is the code I am using: TIFFImageReaderSpi readerSpi= new TIFFImageReaderSpi(); ImageReader imageReader = readerSpi.createReaderInstance(); byte[] data = blobManager.getObjectForIdAndVersion(id, version); ImageInputStream imageInputStream = ImageIO.createImageInputStream(data); imageReader.setInput(imageInputStream); TIFFImageWriterSpi writerSpi = new TIFFImageWriterSpi(); ImageWriter imageWriter = writerSpi.createWriterInstance(); ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam(); imageWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED); //bufferFile is created in the constructor ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(bufferFile); imageWriter.setOutput(imageOutputStream); //Now read the bitmap BufferedImage bufferedImage = imageReader.read(0); IIOImage iIOImage = new IIOImage(bufferedImage, null, null); //and write it imageWriter.write(null, iIOImage, imageWriteParam); Unfortunately, the files that I receive are often very large and the BufferedImage cannot be created. I have been trying to find a way to stream from the ImageReader directly to the ImageWriter but I cannot find out how to do that. Anybody with a suggestion?

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  • [C#] How to use delegate to perform callback between caller and web service helper class?

    - by codemonkie
    I have 2 classes A and B, where they belongs to the same namespace but resides in seperate files namely a.cs and b.cs, where class B essentially is a helper wrapping a web service call as follow: public class A { public A() // constructor { protected static B b = new B(); } private void processResult1(string result) { // come here when result is successful } private void processResult2(string result) { // come here when result is failed } static void main() { b.DoJobHelper(...); } } public class B { private com.nowhere.somewebservice ws; public B() { this.ws = new com.nowhere.somewebservice(); ws.JobCompleted += new JobCompletedEventHandler(OnCompleted); } void OnCompleted(object sender, JobCompletedEventArgs e) { string s; Guid taskID = (Guid)e.UserState; switch (s) { case "Success": // Call processResult1(); break; case "Failed": // Call processResult2(); break; default: break; } } public void DoJobHelper() { Object userState = Guid.NewGuid(); ws.DoJob(..., userState); } } (1) I have seen texts on the net on using delegates for callbacks but failed to apply that to my case. All I want to do is to call the appropriate processResult() method upon OnCompleted() event, but dunno how to and where to declare the delegate: public delegate void CallBack(string s); (2) There is a sender object passed in to OnCompleted() but never used, did I miss anything there? Or how can I make good use of sender? Any helps appreciated.

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  • Avoiding Service Locator with AutoFac 2

    - by Page Brooks
    I'm building an application which uses AutoFac 2 for DI. I've been reading that using a static IoCHelper (Service Locator) should be avoided. IoCHelper.cs public static class IoCHelper { private static AutofacDependencyResolver _resolver; public static void InitializeWith(AutofacDependencyResolver resolver) { _resolver = resolver; } public static T Resolve<T>() { return _resolver.Resolve<T>(); } } From answers to a previous question, I found a way to help reduce the need for using my IoCHelper in my UnitOfWork through the use of Auto-generated Factories. Continuing down this path, I'm curious if I can completely eliminate my IoCHelper. Here is the scenario: I have a static Settings class that serves as a wrapper around my configuration implementation. Since the Settings class is a dependency to a majority of my other classes, the wrapper keeps me from having to inject the settings class all over my application. Settings.cs public static class Settings { public static IAppSettings AppSettings { get { return IoCHelper.Resolve<IAppSettings>(); } } } public interface IAppSettings { string Setting1 { get; } string Setting2 { get; } } public class AppSettings : IAppSettings { public string Setting1 { get { return GetSettings().AppSettings["setting1"]; } } public string Setting2 { get { return GetSettings().AppSettings["setting2"]; } } protected static IConfigurationSettings GetSettings() { return IoCHelper.Resolve<IConfigurationSettings>(); } } Is there a way to handle this without using a service locator and without having to resort to injecting AppSettings into each and every class? Listed below are the 3 areas in which I keep leaning on ServiceLocator instead of constructor injection: AppSettings Logging Caching

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  • UIViewController remaining

    - by Guy
    Hi Guys. I have a UIViewController named equationVC who's user interface is being programmatically created from another NSObject class called equationCon. Upon loading equationVC, a method called chooseInterface is called from the equationCon class. I have a global variable (globalVar) that points to a user defined string. chooseInterface finds a method in the equationCon class that matches the string globalVar points to. In this case, let's say that globalVar points to a string that is called "methodThatMatches." In methodThatMatches, another view controller needs to show the results of what methodThatMatches did. methodThatMatches creates a new equationVC that calls upon methodThatMatches2. As a test, each method changes the color of the background. When the application starts up, I get a purple background, but as soon as I hit backwards I get another purple screen, which should be yellow. I do not think that I am release the view properly. Can anyone help? -(void)chooseInterface { NSString* equationTemp = [globalVar stringByReplacingOccurrencesOfString:@" " withString:@""]; equationTemp = [equationTemp stringByReplacingOccurrencesOfString:@"'" withString:@""]; SEL equationName = NSSelectorFromString(equationTemp); NSLog(@"selector! %@",NSStringFromSelector(equationName)); if([self respondsToSelector:equationName]){ [self performSelector:equationName]; } } -(void)methodThatMatches{ self.equationVC.view.backgroundColor = [UIColor yellowColor]; [setGlobalVar:@"methodThatMatches2"]; EquationVC* temp = [[EquationVC alloc] init]; [[self.equationVC navigationController] pushViewController:temp animated:YES ]; [temp release]; } -(void)methodThatmatches2{ self.equationVC.view.backgroundColor = [UIColor purpleColor]; }

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  • Partial Evaluation of ConstantExpression in ExpressionTreeVisitor

    - by Andrew Theken
    Hi all, I am not an Expression Tree master by any stretch of the imagination, what I have is code that looks like this: int external = 10; using(var session = new Session()) { session.Add(new Product { Name = "test1", Price = 20 }); session.Add(new Product {Name = "test", Price = 10}); var product = session.Products.Where(p => p.Price == external).FirstOrDefault(); Assert.Equal(10, product.Price); } Session implements all the IQueryProvider, IQueryable interfaces you'd come to expect from a LINQ Provider. When I execute the query, everything goes to plan until I read the ConstantExpression for "external", at which point, I am at a loss as to how to move forward because: //constant is ConstantExpression for "external" on the right side of the "p.Price == external" expression above. var t = constant.GetType(); //evaluates to class called "<>c__DisplayClass2" - with a member named "external" that has the value 10. The question is basically.. How can I just access the value of the member "external" - is there a way to accomplish this without using reflection? or am I cooked? What am I missing?

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  • How to create a fully lazy singleton for generics

    - by Brendan Vogt
    I have the following code implementation of my generic singleton provider: public sealed class Singleton<T> where T : class, new() { Singleton() { } public static T Instance { get { return SingletonCreator.instance; } } class SingletonCreator { static SingletonCreator() { } internal static readonly T instance = new T(); } } This sample was taken from 2 articles and I merged the code to get me what I wanted: http://www.yoda.arachsys.com/csharp/singleton.html and http://www.codeproject.com/Articles/11111/Generic-Singleton-Provider. This is how I tried to use the code above: public class MyClass { public static IMyInterface Initialize() { if (Singleton<IMyInterface>.Instance == null // Error 1 { Singleton<IMyInterface>.Instance = CreateEngineInstance(); // Error 2 Singleton<IMyInterface>.Instance.Initialize(); } return Singleton<IMyInterface>.Instance; } } And the interface: public interface IMyInterface { } The error at Error 1 is: 'MyProject.IMyInterace' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method 'MyProject.Singleton<T>' The error at Error 2 is: Property or indexer 'MyProject.Singleton<MyProject.IMyInterface>.Instance' cannot be assigned to -- it is read only How can I fix this so that it is in line with the 2 articles mentioned above? Any other ideas or suggestions are appreciated.

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  • Need help with WCF design

    - by Jason
    I have been tasked with creating a set of web services. We are a Microsoft shop, so I will be using WCF for this project. There is an interesting design consideration that I haven't been able to figure out a solution for yet. I'll try to explain it with an example: My WCF service exposes a method named Foo(). 10 different users call Foo() at roughly the same time. I have 5 special resources called R1, R2, R3, R4, and R5. We don't really need to know what the resource is, other than the fact that a particular resource can only be in use by one caller at a time. Foo() is responsible to performing an action using one of these special resources. So, in a round-robin fashion, Foo() needs to find a resource that is not in use. If no resources are available, it must wait for one to be freed up. At first, this seems like an easy task. I could maybe create a singleton that keeps track of which resources are currently in use. The big problem is the fact that I need this solution to be viable in a web farm scenario. I'm sure there is a good solution to this problem, but I've just never run across this scenario before. I need some sort of resource tracker / provider that can be shared between multiple WCF hosts. Any ideas from the architects out there would be greatly appreciated!

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  • Scrollbar with Sprite and Rectangle won't move text, just the Rectangle it's painted on.

    - by WebDevHobo
    Warning: school assignment. For those of you still with me, I am tasked with making some scrollable content in Flash. Load in a TextFile using LoadURL(), then display it. To get the text, we've written our own class TextFieldExtended, which is basically just there to give the textfile location to the constructor and then have the class do the various steps of getting it and loading it for you. So I needed to get a Scrollbar, which I got here: http://kirupa.com/forum/showthread.php?t=245468 (all files in a zip linked at the end of this text) The thing is, it works with Sprites. After trying to get it to accept TextFieldExtended, I bumped into a block, since the scrollbar relied heavily on a Sprite property that TextFieldExtended didn't have or could have. So I tried adding the TextFieldExtended instance to a Sprite instance using addchild. A problem occurs here that I do not know how to handle. It seems that a Rectangle is drawn and the Text is drawn on that. I say this because the scrollbar moves the Rectangle up and down a bit, but the text doesn't scroll, just the Rectangle it is positioned in and the text then moves along with it. My question: can this be fixed, or is does this implementation of scrollbars need a lot of adaptations before this is possible? If so, any scrollbars you can recommend, because it's too extended for me at this point. All files: http://www.mediafire.com/?q2ium22gmox This was made in Flash CS4 using ActionScript3. The Example class is the final implementation

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  • Can't empty JS array....

    - by solefald
    Yes, I am having issues with this very basic (or so it seems) thing. I am pretty new to JS and still trying to get my head around it, but I am pretty familiar with PHP and have never experienced anything like this. I just can not empty this damn array, and stuff keeps getting added to the end every time i run this. I have no idea why, and i am starting to think that it is somehow related to the way chekbox id's are named, but i may be mistaking.... id="alias[1321-213]", id="alias[1128-397]", id="alias[77-5467]" and so on. I have tried sticking checkboxes = []; and checkboxes.length = 0; In every place possible. Right after the beginning of the function, at the end of the function, even outside, right before the function, but it does not help, and the only way to empty this array is to reload the page. Please tell me what I am doing wrong, or at least point me to a place where i can RTFM. I am completely out of ideas here. function() { var checkboxes = new Array(); checkboxes = $(':input[name="checkbox"]'); $.each(checkboxes, function(key, value) { console.log(value.id); alert(value.id); } ); checkboxes.length = 0; } I have also read Mastering Javascript Arrays 3 times to make sure I am not doing something wrong, but still can't figure it out....

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  • Django 'ImproperlyConfigured' error after deployment on google app engine

    - by oreon
    Hello, I'm currently trying to get my first django project running on Google App Engine. I followed the instructions given here http://www.allbuttonspressed.com/projects/djangoappengine as best I could. Unfortunately I have run into some issues. Locally everything runs fine, no problems. I then tried to deploy my project to the cloud. This is where I'm totally stuck. I always receive 500 Server Errors coupled with google.appengine.runtime.DeadlineExceededError's. Every now and then I get the following error message in my logs, which I think is the root of the problem : <class 'django.core.exceptions.ImproperlyConfigured'>: ImportError projectyalanda.pricecompare: No module named projectyalanda.pricecompare Obviously something is wrong in the way I reference my django app. Why this is only an issue in the cloud is a mystery to me. The interesting part in the settings.py file is setup as following: INSTALLED_APPS = ( 'djangotoolbox', # 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'projectyalanda.pricecompare', ) I absolutely can't figure out why django/appengine wouldn't be able to find the module, especially since everything works perfectly locally. So where else can I look? The local folder structure is of course also correct as automatically done by django, so maybe something is messed up during deployment? How would I be able to find out? Please help me ;-) Thanks

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  • EAGLContext, EAGLSharegroups, RenderBuffers, FrameBuffers, oh my!

    - by quixoto
    Hi all, I'm trying to wrap my head around the OpenGL object model on iPhone OS. I'm currently rendering into a few different UIViews (build on CAEAGLayers) on the screen. I currently have each of these as using separate EAGLContext, each of which has a color renderbuffer and a framebuffer. I'm rendering similar things in them, and I'd like to share textures between these instances to save memory overhead. My current understanding is that I could use the same setup (some number of contexts, each with a FBO/RBO) but if I spawn the later ones using the EAGLShareGroup of the first one, then I can simply use the texture names (GLuints) from the first one in the later ones. Is this accurate? If this is the case, I guess the followup question is: what's the benefit to having it be a "sharegroup"? Could I just reuse the same context, and attach multiple FBOs/RBOs to that context? I think I'm struggling with the abstraction layer of a sharegroup, which seems to share "objects" (textures and other named things) but not "state" (matrices, enabled/disabled states) which are owned by the context. What's the best way to think of this? Thanks for any enlightenment!

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  • I write barely functional scripts that tend to not be resuable and make the baby jesus cry. Please h

    - by maxxpower
    I received a request to add around 100 users to a linux box the users are already in ldap so I can't just use newusers and point it at a text file. Another admin is taking care of the ldap piece so all I have to do is create all the home directories and chown them to the correct user once he adds the users to the box. creating the directories isn't a problem, but I'd like a more elegant script for chowning them to the correct user. what I have currently basically looks like chown -R testuser1 testgroup1 /home/tetsuser1; chown -R testuser2 testgroup2 /home/testgroup2; chown -R testsuser3 testgroup1 /home/testuser3 bascially I took the request that the user name and group name popped it into excel added a column of "chown -R" to the front, then added a column of "/", copied and pasted the username column after it and then added a column of ";" and dragged it down to the second to last row. Popped it into notepad ran some quick find and replaces and in less than a minute I have a completed request and a sad empty feeling. I know this was a really ghetto method and I'm trying to get away from using excel to avoid learning new scripting techniques so here's my real question. tl;dr I made 100 home directories and chowned them to the correct users, but it was ugly. Actual question below. You have a file named idlist that looks like this (only with say 1000 users and real usernames and groups) testuser1 testgroup1 testuser2 testgroup2 testuser3 testgroup1 write a script that creates home directories for all the users and chowns the created directories to the correct user and group. To make the directories I used the following(feel free to flame/correct me on this as well. ) var= 'cut -f1 -d" " idlist' (I used backticks not apostrophes around the cut command) mkdir $var

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  • return value (not a reference) from the function, bound to a const reference in the calling function

    - by brainydexter
    "If you return a value (not a reference) from the function, then bind it to a const reference in the calling function, its lifetime would be extended to the scope of the calling function." So: const BoundingBox Player::GetBoundingBox(void) { return BoundingBox( &GetBoundingSphere() ); } Returns a value of type const BoundingBox from function GetBoundingBox() Called function: (From within function Update() the following is called:) variant I: (Bind it to a const reference) const BoundingBox& l_Bbox = l_pPlayer->GetBoundingBox(); variant II: (Bind it to a const copy) const BoundingBox l_Bbox = l_pPlayer->GetBoundingBox(); Both work fine and I don't see the l_Bbox object going out of scope. (Though, I understand in variant one, the copy constructor is not called and thus is slightly better than variant II). Also, for comparison, I made the following changes. BoundingBox Player::GetBoundingBox(void) { return BoundingBox( &GetBoundingSphere() ); } with Variants: I BoundingBox& l_Bbox = l_pPlayer->GetBoundingBox(); and II: BoundingBox l_Bbox = l_pPlayer->GetBoundingBox(); The objet l_Bbox still does not out scope. So, I don't see how "bind it to a const reference in the calling function, its lifetime would be extended to the scope of the calling function", really extends the lifetime of the object to the scope of the calling function ? Am I missing something trivial here..please explain .. Thanks a lot

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  • How do I lookup a JNDI Datasource from outside a web container?

    - by masotime
    I have the following environment set up: Java 1.5 Sun Application Server 8.2 Oracle 10 XE Struts 2 Hibernate I'm interested to know how I can write code for a Java client (i.e. outside of a web application) that can reference the JNDI datasource provided by the application server. The ports for the Sun Application Server are all at their defaults. There is a JNDI datasource named jdbc/xxxx in the server configuration, but I noticed that the Hibernate configuration for the web application uses the name java:comp/env/jdbc/xxxx instead. Most of the examples I've seen so far involve code like Context ctx = new InitialContext(); ctx.lookup("jdbc/xxxx"); But it seems I'm either using the wrong JNDI name, or I need to configure a jndi.properties or other configuration file to correctly point to a listener? I have appserv-rt.jar from the Sun Application Server which has a jndi.properties inside of it, but it does not seem to help. There's a similar question here, but it doesn't give any code / refers to having iBatis obtain the JNDI Datasource automatically: http://stackoverflow.com/questions/39053/accessing-datasource-from-outside-a-web-container-through-jndi

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