Sharing NSOperationQueue across View Controllers?

Question

I\'m using an NSOperationQueue to manage HTTP connections (using ASI-HTTPRequest). Since I have multiple views and the need to have these different views requesting HTTP connect

Answer 1

I have solved this by adding a class method on NSOperationQueue that I think Apple has missed; a shared operation queue. I add this as a category on NSOperationQueue as this:

// NSOperationQueue+SharedQueue.h
@interface NSOperationQueue (SharedQueue)
+(NSOperationQueue*)sharedOperationQueue;
@end

// NSOperationQueue+SharedQueue.m
@implementation NSOperationQueue (SharedQueue)
+(NSOperationQueue*)sharedOperationQueue;
{
  static NSOperationQueue* sharedQueue = nil;
  if (sharedQueue == nil) {
    sharedQueue = [[NSOperationQueue alloc] init];
  }
  return sharedQueue;
}
@end

This way I do not need to manage a whole bunch of queues unless I really need to. I have easy access to a shared queue from all my view controllers.

I have even added a category to NSObject to make it even easier to add new operations on this shared queue:

// NSObject+SharedQueue.h
@interface NSObject (SharedQueue)
-(void)performSelectorOnBackgroundQueue:(SEL)aSelector withObject:(id)anObject;
@end

// NSObject+SharedQueue.m
@implementation NSObject (SharedQueue)
-(void)performSelectorOnBackgroundQueue:(SEL)aSelector withObject:(id)anObject;
{
  NSOperation* operation = [[NSInvocationOperation alloc] initWithTarget:self
                                                                selector:aSelector
                                                                  object:anObject];
  [[NSOperationQueue sharedOperationQueue] addOperation:operation];
  [operation release];
}
@end