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  • IPhone Objectvie C

    - by Sea
    I am trying to determine if a UILabel was touched and if so do something. Give .. . . . UILabel * site = [[UILabel alloc] initWithFrame:CGRectMake(0, 185, 320, 30)]; site.text = [retriever.plistDict valueForKey:@"url"]; site.textAlignment =UITextAlignmentCenter; site.backgroundColor = [UIColor clearColor]; site.textColor = [UIColor whiteColor]; site.userInteractionEnabled = YES; [theBgView addSubview:site]; [site release]; . . . Then I write the callback. - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{ retriever = [PListRetriever sharedInstance]; CGPoint pt = [[touches anyObject] locationInView: self]; NSURL *target = [[NSURL alloc] initWithString:[retriever.plistDict valueForKey:@"url"]]; [[UIApplication sharedApplication] openURL:target]; } The problem is right now, no matter where I touch in the View the Url is being opened. How do I determine if only just my label was touched?

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  • Objective-C subclass and base class casting

    - by ryanjm.mp
    I'm going to create a base class that implements very similar functions for all of the subclasses. This was answered in a different question. But what I need to know now is if/how I can cast various functions (in the base class) to return the subclass object. This is both for a given function but also a function call in it. (I'm working with CoreData by the way) As a function within the base class (this is from a class that is going to become my subclass) +(Structure *)fetchStructureByID:(NSNumber *)structureID inContext:(NSManagedObjectContext *)managedObjectContext {...} And as a function call within a given function: Structure *newStructure = [Structure fetchStructureByID:[currentDictionary objectForKey:@"myId"]]; inContext:managedObjectContext]; Structure is one of my subclasses, so I need to rewrite both of these so that they are "generic" and can be applied to other subclasses (whoever is calling the function). How do I do that? Update: I just realized that in the second part there are actually two issues. You can't change [Structure fetch...] to [self fetch...] because it is a class method, not an instance method. How do I get around that too?

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  • Javascript Selectbox refresh necessary in YUI 3, when selecting none?

    - by Jasie
    Hi all, I'm using YUI 3 to let someone click "Select All" or "Select None" and then have the selectbox select all the items or unselect all of them, respectively. Here's my code: // This selects all Y.on('click',function (e) { selectBoxNode.get("options").each(function () { this.removeAttribute('selected'); this.setAttribute('selected','selected'); }); }, selectAllNode ); // This selects none Y.on('click',function (e) { selectBoxNode.get("options").each(function () { this.setAttribute('selected','false'); this.removeAttribute('selected'); }); selectBoxNode.('selectedIndex',-1); }, selectNoneNode ); selectAllLink, selectNoneLink, and selectBoxNode are self-evident, properly returned Nodes. Update: selectAll works, I had to manually remove the 'selected' attribute for each and re-add it. The selectNoneLink doesn't work: it unselects only the elements that weren't before selected... although DOM inspection shows that the selectedIndex attribute is indeed changed to -1, so maybe it needs a refresh? Any help would be appreciated. If this happens in all frameworks, that would be nice to know as well. Thanks!

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  • iPhone NSTimer OpenGL problem

    - by Toby Wilson
    I've got a problem that only seems to occur on the device, not in the simulator. My app's animation is started and stopped using these methods: NSTimer* animationTimer; -(void)startAnimation { if(animationTimer = nil) animationTimer = [NSTimer scheduledTimerWithTimeInterval:1.0f/60.0f target:self selector:@selector(drawView) userInfo:nil repeats:YES]; } -(void)stopAnimation { [animationTimer invalidate]; animationTimer = nil; } In the simulator this works fine and drawView starts being called at 60fps. On the device (testing on iPod Touch), the scheduleTimerWithTimeInterval method doesn't seem to work. Furthermore, [animationTimer invalidate] causes EXC_BAD_ACCESS. I've spotted an obvious but minor flaw; adding if(animationTimer != nil) to the stopAnimation method will prevent the crash, but doesn't solve the problem of the animation timer not being properly initialised. Edit: The above doesn't prevent a crash. animationTimer != nil yet calling invalidate causes EXC_BAD_ACCESS. Should also add, this problem doesn't occur all the time on the device. Maybe 40% of the time.

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  • Can't draw UImage in UIView::drawRect

    - by Joel
    I know this seems like a simple task, which is why I don't understand why I can't get the image to render. When I set up my UIView, I do the following: myUiView.backgroundColor = [UIColor clearColor]; myUiView.opaque = NO; I create and retain the UIImage in the init function of my UIView: image = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"test" ofType:@"png"]] retain]; then my drawRect looks like this: - (void) drawRect:(CGRect) rect { [image drawInRect:self.bounds]; } Ultimately I'll be manipulating that UIImage via bitmap context, and then in drawRect create a CGImage out of the context, and render that, but for now I'm just trying to get it rendering a known image. I've been digging through this site, as well as the documentation. I've gone down the CG path and tried drawing it with CGContextDrawImage by following the numerous examples other people have posted, but that didn't work either. So I've come back to what seems to be the most straightforward way to draw an image, but it isn't working. Any help would be greatly appreciated. Thanks in advance.

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  • How to solve the delay problem in animation of sprites ?

    - by srikanth rongali
    My problem is, I did coding for a sprite. It should change it should change it's image from( 1, 2, 3). It should look like count down time to start a game. 1, 2, 3 are 3 png images. But the images are not displayed in equal intervals of time. I mean time between (1 - 2), (2 - 3) is not same. It is random. Please help me with my problem. Help me if there is better solution than what I am doing.(My animation should be like, before any game starts we see count down 1 then 2 then 3 then GO). -(id)init { if((self = [super init])) { [[CCDirector sharedDirector] setAnimationInterval:60.0/60]; [[CCDirector sharedDirector] setDisplayFPS:NO]; CCAnimation* numberAnimation = [CCAnimation animationWithName:@"countDown" delay: 60.0/60]; for( int i=1;i<4;i++) [numberAnimation addFrameWithFilename: [NSString stringWithFormat:@"number_%02d.png", i]]; id numberAction = [CCAnimate actionWithAnimation: numberAnimation restoreOriginalFrame:NO]; id action2 = [CCFadeOut actionWithDuration:0.5f]; CCSprite *number; number = [CCSprite spriteWithFile:@"number.png"]; .... } }

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  • How do I use a custom cookie session serializer in Rack?

    - by Damien Wilson
    Hello SO. I'm currently integrating Warden into a new Rack application I'm building. I'd like to implement a recent patch to Rack that allows me to specify how sessions are serialized; specifically, I'd like to use Rack::Session::Cookie::Identity as the session processor. Unfortunately, the documentation is a little unclear as to what syntax I should use to configure Rack::Session::Cookie in my rackup file, can anyone here tell me what I'm doing wrong? config.ru require 'my_sinatra_app' app = self use Rack::Session::Cookie.new(app, Rack::Session::Cookie::Identity.new), {:key => "auth_token"} use Warden::Manager do |warden| # Must come AFTER Rack::Session warden.default_strategies :password warden.failure_app Jelli::Auth.run! end run MySinatraApp error message from thin !! Unexpected error while processing request: undefined method `new' for #<Rack::Session::Cookie:0x00000110124128> PS: I'm using bundler to manage my gem dependencies and I've likewise included rack's master branch as the desired version. Update: As suggested in the comments below, I have read the documentation; sadly the suggested syntax in the docs is not working. Update: Still no luck on my end; offering up a bounty to whoever can help me figure this out.

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  • Delphi fastMM doesn't work with operator "IS"

    - by Joc02
    I work on Delphi project who interac with many other small libraries. I use FastMM4 and I would like work with complex classes passed on dll parameter. So for exemple I send my form to my dll. Into the dll I test the type of parameter with the operator "IS". But into the Dll the operator "IS" return always "false" Exemple library Dll; uses FastMM4, System.SysUtils, System.Classes, Vcl.Dialogs, Vcl.Forms; {$R *.res} procedure Complex(L : TObject);stdcall; begin if L is TForm then showmessage('Ok') else showmessage('Pas ok') ; if L is TCustomFrame then showmessage('Ok') else showmessage('Pas ok') end; exports Complex; begin end. And the call procedure TffsIsOperator.Button2Click(Sender: TObject); var MaDLL : THandle; Proc : procedure (l : TForm); begin try MaDLL := LoadLibrary(PChar('Dll.dll')); @Proc := GetProcAddress(MaDLL, 'Complex'); Proc(self); finally FreeLibrary(MaDLL); end; end;

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  • ObjC get property name

    - by Joe Even
    Yes. I've searched a lot without success. I've looking for a way to get a property name as StringValue from inside a method. Lets say: My class has X Subviews from the Type UILabel. @property (strong, nonatomic) UILabel *firstLabel; @property (strong, nonatomic) UILabel *secondLabel; [...] and so on. Inside the method foo, the views are iterated as followed: -(void) foo { for (UIView *view in self.subviews) { if( [view isKindOfClass:[UILabel class]] ) { /* codeblock that gets the property name. */ } } } The Result should be something like that: THE propertyName(NSString) OF view(UILabel) IS "firstLabel" I've tried class_getInstanceVariable, object_getIvar and property_getName without Success. For Example, the Code for: [...] property_getName((void*)&view) [...] RETURNS: <UILabel: 0x6b768c0; frame = (65 375; 219 21); text = 'Something'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x6b76930>> But i'm looking for this kind of result: "firstLabel" , "secondLabel" and so on. Thanks for your help! Reagrds Joé

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  • Ruby on Rails Associations

    - by Eef
    Hey all, I am starting to create my sites in Ruby on Rails these days instead of PHP. I have picked up the language easily but still not 100% confident with associations :) I have this situation: User Model has_and_belongs_to_many :roles Roles Model has_and_belongs_to_many :users Journal Model has_and_belongs_to_many :roles So I have a roles_users table and a journals_roles table I can access the user roles like so: user = User.find(1) User.roles This gives me the roles assigned to the user, I can then access the journal model like so: journals = user.roles.first.journals This gets me the journals associated with the user based on the roles. I want to be able to access the journals like so user.journals In my user model I have tried this: def journals self.roles.collect { |role| role.journals }.flatten end This gets me the journals in a flatten array but unfortunately I am unable to access anything associated with journals in this case, e.g in the journals model it has: has_many :items When I try to access user.journals.items it does not work as it is a flatten array which I am trying to access the has_many association. Is it possible to get the user.journals another way other than the way I have shown above with the collect method? Hope you guys understand what I mean, if not let me know and ill try to explain it better. Cheers Eef

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  • How to add images while moving finger across UIView?

    - by Luke Irvin
    I am having issues adding an image across a view while moving finger across the screen. Currently it is adding the image multiple times but squeezing them too close together and not really following my touch. Here is what I am trying: -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch * touch = [touches anyObject]; touchPoint = [touch locationInView:imageView]; if (touchPoint.x > 0 && touchPoint.y > 0) { _aImageView = [[UIImageView alloc] initWithImage:aImage]; _aImageView.multipleTouchEnabled = YES; _aImageView.userInteractionEnabled = YES; [_aImageView setFrame:CGRectMake(touchPoint.x, touchPoint.y, 80.0, 80.0)]; [imageView addSubview:_aImageView]; [_aImageView release]; } } -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [self touchesBegan:touches withEvent:event]; } Any suggestions is much appreciated. EDIT: What I want: After taking or choosing an image, the user can then select another image from a list. I want the user to touch and move their finger across the view and the selected image will appear where they drag their finger, without overlapping, in each location.

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  • Core-Plot crash only in Release Configuration

    - by denbec
    Hey everyone, I really don't know a solution or even an idea to get around the following failure. It only happens in Release Configuration on the Device - Simulator and Debug Configuration work fine. It also only appears on the second launch. So if I have the phone connected to my mac, build the application and run it, everything works fine. If I then close the app and restart, it crashes. After long search, it seems that the error comes from the following line: x.majorIntervalLength = CPDecimalFromFloat(2.0f); The code before: CPLayerHostingView *chartView = [[CPLayerHostingView alloc] initWithFrame:CGRectMake(0, 0, 320, 160)]; [self addSubview:chartView]; // create an CPXYGraph and host it inside the view CPTheme *theme = [CPTheme themeNamed:kCPPlainWhiteTheme]; CPXYGraph *graph = (CPXYGraph *)[theme newGraph]; chartView.hostedLayer = graph; graph.paddingLeft = 20.0; graph.paddingTop = 10.0; graph.paddingRight = 10.0; graph.paddingBottom = 20.0; CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace; plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0) length:CPDecimalFromFloat(100)]; plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0) length:CPDecimalFromFloat(10)]; CPXYAxisSet *axisSet = (CPXYAxisSet *)graph.axisSet; CPXYAxis *x = axisSet.xAxis; x.majorIntervalLength = CPDecimalFromFloat(2.0f); If I comment the last line, everything works fine (off course the interval length is not correct). I would appreciate any help! Thanks in advance!

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  • routes as explained in RoR tutorial 2nd Ed?

    - by 7stud
    The author, Michael Hartl, says: Here the rule: get "static_pages/home" maps requests for the URI /static_pages/home to the home action in the StaticPages controller. How? The type of request is given, the url is given, but where is the mapping to a controller and action? My tests all pass, though. I also tried deleting all the actions in the StaticPagesController, which just looks like this: class StaticPagesController < ApplicationController def home end def about end def help end def contact end end ...and my tests still pass, which is puzzling. The 2nd edition of the book(online) is really frustrating. Specifically, the section about making changes to the Guardfile is impossible to follow. For instance, if I instruct you to edit this file: blah blah blah dog dog dog beetle beetle beetle jump jump jump and make these changes: blah blah blah . . . go go go . . . jump jump jump ...would you have any idea where the line 'go go go' should be in the code? And the hint for exercise 3.5-1 is flat out wrong. If the author would put up a comment section at the end of every chapter, the rails community could self-edit the book.

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  • Error copying file from app bundle

    - by Michael Chen
    I used the FireFox add-on SQLite Manager, created a database, which saved to my desktop as "DB.sqlite". I copied the file into my supporting files for the project. But when I run the app, immediately I get the error "Assertion failure in -[AppDelegate copyDatabaseIfNeeded], /Users/Mac/Desktop/Note/Note/AppDelegate.m:32 2014-08-19 23:38:02.830 Note[28309:60b] Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Failed to create writable database file with message 'The operation couldn’t be completed. (Cocoa error 4.)'.' First throw call stack: "... Here is the App Delegate Code where the error takes place -(void) copyDatabaseIfNeeded { NSFileManager *fileManager = [NSFileManager defaultManager]; NSError *error; NSString *dbPath = [self getDBPath]; BOOL success = [fileManager fileExistsAtPath:dbPath]; if (!success) { NSString *defaultDBPath = [[ [NSBundle mainBundle ] resourcePath] stringByAppendingPathComponent:@"DB.sqlite"]; success = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error]; if (!success) NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]); } } I am very new to Sqlite, so I maybe I didn't create a database correctly in the FireFox Sqlite manager, or maybe I didn't "properly" copy the .sqlite file in? (I did check the target membership in the sqlite and it correctly has my project selected. Also, the .sqlite file names all match up perfectly.)

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  • NSTimer Reset Not Working

    - by user355900
    hi, i have a nstimer and it works perfectly counting down from 2:00 but when i hit the reset button it does not work it just stops the timer and when i press start again it will carry on with the timer as if it had never been stopped. Here is my code `@implementation TimerAppDelegate @synthesize window; (void)applicationDidFinishLaunching:(UIApplication *)application { timerLabel.text = @"2:00"; seconds = 120; // Override point for customization after application launch [window makeKeyAndVisible]; } (void)viewDidLoad { [timer invalidate]; } (void)countDownOneSecond { seconds--; int currentTime = [timerLabel.text intValue]; int newTime = currentTime - 1; int displaySeconds = !(seconds % 60) ? 0 : seconds < 60 ? seconds : seconds - 60; int displayMinutes = floor(seconds / 60); NSString *time = [NSString stringWithFormat:@"%d:%@%d", displayMinutes, [[NSString stringWithFormat:@"%d", displaySeconds] length] == 1 ? @"0" : @"", displaySeconds ]; timerLabel.text = time; if(seconds == 0) { [timer invalidate]; } } (void)startOrStopTimer { if(timerIsRunning){ [timer invalidate]; [startOrStopButton setTitle:@"Start" forState:UIControlStateNormal]; } else { timer = [[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(countDownOneSecond) userInfo:nil repeats:YES] retain]; [startOrStopButton setTitle:@"Stop" forState:UIControlStateNormal]; } timerIsRunning = !timerIsRunning; } (void)resetTimer { [timer invalidate]; [startOrStopButton setTitle:@"Start" forState:UIControlStateNormal]; [timer invalidate]; timerLabel.text = @"2:00"; } (void)dealloc { [window release]; [super dealloc]; } @end` thanks

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  • Rexml - Parsing Data

    - by Paddy
    I have a XML File in the following format: <?xml version='1.0' encoding='UTF-8'?> <entry xmlns='http://www.w3.org/2005/Atom' xmlns:gwo='http://schemas.google.com/analytics/websiteoptimizer/2009' xmlns:app='http://www.w3.org/2007/app' xmlns:gd='http://schemas.google.com/g/2005' gd:etag='W/&quot;DUYGRX85fCp7I2A9WxFWEkQ.&quot;'><id>https://www.google.com/analytics/feeds/websiteoptimizer/experiments/1025910</id><updated>2010-05-31T02:12:04.124-07:00</updated><app:edited>2010-05-31T02:12:04.124-07:00</app:edited><title>Flow Experiment</title><link rel='gwo:goalUrl' type='text/html' href='http://cart.personallifemedia.com/dlg/download.php'/><link rel='alternate' type='text/html' href='https://www.google.com/websiteoptimizer'/><link rel='self' type='application/atom+xml' href='https://www.google.com/analytics/feeds/websiteoptimizer/experiments/1025910'/><gwo:analyticsAccountId>16334726</gwo:analyticsAccountId><gwo:autoPruneMode>None</gwo:autoPruneMode><gwo:controlScript>..... I have to parse and get the data for gd:etag and how do I do it? I was able to get the value using SimpleXML, but i wanted to achieve it in ReXML. Please do advice.

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  • Who to access a UIButton using tag and button change image?

    - by ste
    I need to change the images on a matrix of UIButtons, and the only thing I know of to address the buttons, is the tag. But I can not find a way to actually us this identifier. The buttons are created programmatically during viewDidLoad. Here is the code for creating the buttons: #define N_ROWS 4 #define N_COLS 3 int N_IMG = 0; for (int a = 0; a < N_COLS; a++) { for (int j = 0; j < N_ROWS; j++) { UIButton *aButton = [UIButton buttonWithType:UIButtonTypeCustom]; aButton.frame = CGRectMake(a * 65.0 + 25, j * 65.0 + 15, 10.0, 10.0); aButton.tag = j + a * N_ROWS + 1; [aButton setBackgroundColor:[UIColor redColor]]; N_IMG = N_IMG++; [self.view addSubview:aButton]; number_sorted = 1; } } Here is the code for setting the image: - (IBAction)set_image:(id)sender { #define N_ROWS 4 #define N_COLS 3 int N_IMG = 0; for (int a = 0; a < N_COLS; a++) { for (int j = 0; j < N_ROWS; j++) { uibutton aButton.tag == (j + a * N_ROWS + 1) setImage:[UIImage imageNamed:[puzzles objectAtIndex:N_IMG]] forState:UIControlStateNormal]; N_IMG = N_IMG++; } } } This is the code where the truble starts: uibutton aButton.tag == (j + a * N_ROWS + 1) Who can I set this up to work?

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  • How to synchronize Silverlight clients with WCF?

    - by user564226
    Hi, this is probably only some conceptual problem, but I cannot seem to find the ideal solution. I'd like to create a Silverlight client application that uses WCF to control a third party application via some self written webservice. If there is more than one Silverlight client, all clients should be synchronized, i.e. parameter changes from one client should be propagated to all clients. I set up a very simple Silverlight GUI that manipulates parameters which are passed to the server (class inherits INotifyPropertyChanged): public double Height { get { return frameworkElement.Height; } set { if (frameworkElement.Height != value) { frameworkElement.Height = value; OnPropertyChanged("Height", value); } } } OnPropertyChanged is responsible for transferring data. The WCF service (duplex net.tcp) maintains a list of all clients and as soon as it receives a data packet (XElement with parameter change description) it forwards this very packet to all clients but the one the packet was received from. The client receives the package, but now I'm not sure, what's the best way to set the property internally. If I use "Height" (see above) a new change message would be generated and sent to all other clients a.s.o. Maybe I could use the data field (frameworkElement.Height) itself or a function - but I'm not sure whether there would arise problems with data binding later on. Also I don't want to simply copy parts of the code properties, to prevent bugs with redundant code. So what would you recommend? Thanks!

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  • UIImage - should be loaded with [UIImage imageNamed:@""] or not ?

    - by sagar
    Hello ! every one. I am having number of images with in my application. ( images more than 50 - approximately & it can extend according to client's need ) Each image are very large round about - 1024 x 768 & 150 dpi Now, I have to add all this images in a scroll view & display it. Ok, My question is as follows. According to me there are two options of loading large images imageNamed:@"" load asynchronously when viewDidLoad Called. Which is more preferable ? imgModel.image=[UIImage imageNamed:[dMain valueForKey:@"imgVal"]]; or like this. NSURL *ur=[[NSURL alloc] initFileURLWithPath:[[NSBundle mainBundle] pathForResource:lblModelName.text ofType:@"png"] isDirectory:NO]; NSURLRequest *req=[NSURLRequest requestWithURL:ur cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:40]; [ur release]; NSURLConnection *con=[[NSURLConnection alloc] initWithRequest:req delegate:self]; if(con){ myWebData=[[NSMutableData data] retain]; } else { } -(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { [myWebData setLength: 0]; } -(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [myWebData appendData:data]; } -(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { [connection release]; } -(void)connectionDidFinishLoading:(NSURLConnection *)connection { NSLog(@"ImageView Ref From - %@",imgV); // my image view & set image imgV.image=[UIImage imageWithData:myWebData]; [connection release]; connection=nil; }

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  • Blackberry Asynchronous HTTP Requests - How?

    - by Kai
    The app I'm working on has a self contained database. The only time I need HTTP request is when the user first loads the app. I do this by calling a class that verifies whether or not a local DB exists and, if not, create one with the following request: HttpRequest data = new HttpRequest("http://www.somedomain.com/xml", "GET", this); data.start(); This xml returns a list of content, all of which have images that I want to fetch AFTER the original request is complete and stored. So something like this won't work: HttpRequest data = new HttpRequest("http://www.somedomain.com/xml", "GET", this); data.start(); HttpRequest images = new HttpRequest("http://www.somedomain.com/xmlImages", "GET", this); images.start(); Since it will not treat this like an asynchronous request. I have not found much information on adding callbacks to httpRequest, or any other method I could use to ensure operation 2 does not execute until operation 1 is complete. Any help would be appreciated. Thanks

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  • How do I programatically verify, create, and update SQL table structure?

    - by JYelton
    Scenario: I have an application (C#) that expects a SQL database and login, which are set by a user. Once connected, it checks for the existence of several table and creates them if not found. I'd like to expand on this by having the program be capable of adding columns to those tables if I release a new version of the program which relies upon the new columns. Question: What is the best way to programatically check the structure of an existing SQL table and create or update it to match an expected structure? I am planning to iterate through the list of required columns and alter the existing table whenever it does not contain the new column. I can't help but wonder if there's an approach that is different or better. Criteria: Here are some of my expectations and self-imposed rules: Newer versions of the program might no longer use certain columns, but they would be retained for data logging purposes. In other words, no columns will be removed. Existing data in the table must be preserved, so the table cannot simply be dropped and recreated. In all cases, newly added columns would allow null data, so the population of old records is taken care of by having default null values. Example: Here is a sample table (because visual examples help!): id sensor_name sensor_status x1 x2 x3 x4 1 na019 OK 0.01 0.21 1.41 1.22 Then, in a new version, I may want to add the column x5. The "x-columns" are all data-storage columns that accept null.

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  • Ruby: Why is Array.sort slow for large objects?

    - by David Waller
    A colleague needed to sort an array of ActiveRecord objects in a Rails app. He tried the obvious Array.sort! but it seemed surprisingly slow, taking 32s for an array of 3700 objects. So just in case it was these big fat objects slowing things down, he reimplemented the sort by sorting an array of small objects, then reordering the original array of ActiveRecord objects to match - as shown in the code below. Tada! The sort now takes 700ms. That really surprised me. Does Ruby's sort method end up copying objects about the place rather than just references? He's using Ruby 1.8.6/7. def self.sort_events(events) event_sorters = Array.new(events.length) {|i| EventSorter.new(i, events[i])} event_sorters.sort! event_sorters.collect {|es| events[es.index]} end private # Class used by sort_events class EventSorter attr_reader :sqn attr_reader :time attr_reader :index def initialize(index, event) @index = index @sqn = event.sqn @time = event.time end def <=>(b) @time != b.time ? @time <=> b.time : @sqn <=> b.sqn end end

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  • How do I implement configurations and settings?

    - by Malvolio
    I'm writing a system that is deployed in several places and each site needs its own configurations and settings. A "configuration" is a named value that is necessary to a particular site (e.g., the database URL, S3 bucket name); every configuration is necessary, there is not usually a default, and it's typically string-valued. A setting is a named value but it just tweaks the behavior of the system; it's often numeric or Boolean, and there's usually some default. So far, I've been using property files or thing like them, but it's a terrible solution. Several times, a developer has added a requirement for a configuration but not added the value to file for the live configuration, so the new release passed all the tests, then failed when released to live. Better, of course, for every file to be compiled — so if there's a missing configuration, or one of the wrong type, it won't get past the compiler — and inject the site-specific class into the build for each site. As a bones, a Scala file can easy model more complex values, especially lists, but also maps and tuples. The downside is, the files are sometimes maintained by people who aren't developers, so it has to be pretty self-explanatory, which was the advantage of property files. (Someone explain XML configurations to me: all the complexity of a compilable file but the run-time risk of a property file.) What I'm looking for is an easy pattern for defining a group required names and allowable values. Any suggestions?

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  • From Sinatra Base object. Get port of application including the base object

    - by Poul
    I have a Sinatra::Base object that I would like to include in all of my web apps. In that base class I have the configure method which is called on start-up. I would like that configure code to 'register' that service with a centralized database. The information that needs to be sent when registering is the information on how to contact this web-service... things like host and port. I then plan on having a monitoring service that will spin over all registered services and occasionally ping them to make sure they are still up and running. In the configure method I am having trouble getting the port information. The 'self.settings.port' variable doesn't seem to work in this method. a) any ideas on how to get the port? I have the host. b) is there a sinatra plug-in that already does something like this so I don't have to write it myself? :-) //in my Sinatra::Base code. lets call it register_me.rb RegisterMe < Sinatra::Base configure do //save host and port information to database end get '/check_status' //return status end //in my web service code require register_me //at this point, sinatra will initialize the RegisterMe object and call configure post ('/blah') //example of a method for this particular web service end

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  • How do I push another viewController onto the navigationController from within a tabviewController?

    - by user207788
    Hi, I have a project set up using these two tutorials. http://twilloapp.blogspot.com/2009/03/how-to-embed-navigation-controller.html and the link for the second tutorial is at the bottom of the first. The tutorial is slightly outdated but I managed to get it to work as advertised. Now I want to push a new detailedView onto the NavigationController when a user touches a row in the table view. So I added this to my MyTableViewController.m file. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. SecondViewController *detailViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController.xib" bundle:nil]; // ... // Pass the selected object to the new view controller. [self.navigationController pushViewController:detailViewController animated:YES]; [detailViewController release]; } Now when I run this project and touch a row in my table view I am getting an error: asm_Terminating_due_to_uncaught_exception IT seems to be having an issue loading the SecondViewController from nib, however I checked the detailViewController and it is not nil. I know I am missing something and it is more than likely something simple. Please help. Thanks, Bruce

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