objective-c-blocks

I created an APIController in my application that has several methods that call specific api urls and return a model object populated with the result of the api call. The api works with json and up to now my code looks like the following: //Definition: - (MyModel *)callXYZ; - (MyModel *)callABC; - (MyModel *)call123; //Implementation of one: - (MyModel *)callXYZ { //Build url and call with [NSData dataWithContentsOfURL: url]; //Create model and assign data returned by api return model; } Now I want to use the great AFNetworking framework to get rid of that "dataWithContentsOfURL" calls. So I

I understand that this function first return "images" then "findObjectsInBackgroundWithBlock" retrieve data that's why results is nil. 1 - how to return array from block? 2 - how to put this block not in main thread? +(NSMutableArray *)fetchAllImages{ __block NSMutableArray *images = [NSMutableArray array]; PFQuery *query = [PFQuery queryWithClassName:@"Photo"]; [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) { if (!error) { for (PFObject *object in objects) { PFFile *applicantResume = object[@"imageFile"]; NSData *imageData = [applicantResume getData]; NSString

This question already has an answer here: Return value for function inside a block 3 answers I have a UITableView and I'm attempting to get the number of rows. However, I'm having trouble using blocks. In the code below I'd just like to return count, but as I now understand blocks are asynchronous. I've looked around trying to find a solution but none of them worked. One solution I tried was this: How do I wait for an asynchronously dispatched block to finish? but when I clicked on the button to go to the view with the table, it just froze when the button was clicked. I tried some others, but

I got the this code in a class: - (void)cancel { if (_cancelBlock) _cancelBlock(); } - (void)overrideCancelWithBlock:(void(^)(void))cancelBlock { [_cancelBlock release]; NSLog(@"AsyncOperation-overrideCancelWithBlock-[cancelBlock retainCount]=%lu (before)", [cancelBlock retainCount]); _cancelBlock = [[cancelBlock copy] retain]; NSLog(@"AsyncOperation-overrideCancelWithBlock-[_cancelBlock retainCount]=%lu (after)", [_cancelBlock retainCount]); } - (void)dealloc { NSLog(@"AsyncOperation-dealloc-[_cancelBlock retainCount]=%lu (before)", [_cancelBlock retainCount]); [_cancelBlock release]; NSLog(@

I think I might have an async problem going on here, which bites cause I thought I had solved it. Anyway, I am making a bunch of web service calls like so: //get the client data __block NSArray* arrClientPAs; [dataManager getJSONData:strWebService withBlock:^(id results, NSError* error) { if (error) { UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Getting Client Data Error!" message:error.description delegate:nil cancelButtonTitle:NSLocalizedString(@"Okay", nil) otherButtonTitles:nil, nil]; [alert show]; } else { arrClientPAs = results; } }]; and getJSONData is like so: - (void)

I have using blocks and ARC, and found in some situation, iOS only crash in Release build. It was wrong way to write code, like this. -(IBAction)clickedButtonA:(UIBarButtonItem*)sender event:(UIEvent*)event { NSMutableArray *arrRows = [NSMutableArray arrayWithCapacity:0]; #warning this code only crash on Release Build.... Don't use this NSMutableDictionary * dicRow = [NSMutableDictionary dictionaryWithCapacity:0]; [arrRows addObject:dicRow]; dispatch_block_t block = ^{ NSString *str = [NSString stringWithFormat:@"%@",[_tweet valueForKey:@"text"]]; [[UIPasteboard generalPasteboard] setString

How do we declare a global(private instance variable) to accept a block in it. Do we need to synthesis it & what are the memory management implications with it. I have a block received from a third party method which I want to save in the instance variable & use it at a later stage. Here's an (ARC-less) example of storing a block for a completion callback after doing some work in the background: Worker.h: @interface Worker : NSObject { void (^completion)(void); } @property(nonatomic,copy) void (^completion)(void); - (void)workInBackground; @end Worker.m: @implementation Worker @synthesize