I have the following code:
- (UIImage *) getPublisherLogo
{
//check the cache if the logo already exists
NSString * imageUrl = [NSString stringWithFormat:@"%@/%@&image_type=icon", self.baseUrl, self.imageUrl_];
ASIHTTPRequest * imageRequest = [ASIHTTPRequest requestWithURL:[NSURL URLWithString:imageUrl]];
[imageRequest setTimeOutSeconds:30.0];
[imageRequest setDownloadCache:[ASIDownloadCache sharedCache]];
[imageRequest setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy];
[imageRequest setCachePolicy:ASIAskServerIfModifiedWhenStaleCachePolicy|ASIFallbackToCacheIfLoadFailsCachePolicy];
[imageRequest setCompletionBlock:^(void){
UIImage *img = [UIImage imageWithData:[imageRequest responseData] ];
if (img){
return img;
}
}];
[imageRequest setFailedBlock:^(void){
NSLog(@"Error in pulling image for publisher %@", [[imageRequest error] userInfo]);
}];
[imageRequest startAsynchronous];
}
}
The issue is that the return value/UIImage is returned at a block. How do I avoid this?
You're unable to return anything from the completion block because it's returned void.
ReplyDeleteYou'll probably need to create a new method like setLogo:(UIImage *)image on the object that's expecting the image to be set, and call that method from within the completion block.
You can place your img pointer outside the block and declare it __BLOCK and use it as a closure. But you really need to be asking yourself what do you plan to do with img, bearing in mind the call is made asynchronously. I would imagine you should make another call in the block to another method and pass in the populated image as a parameter.
ReplyDeleteFor getting an object from the ASIHttpRequest response, I use notifications.
ReplyDeleteFor example, in the calling viewController
- (void)viewDidLoad {
// Subscribe notifications
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onGetPhoto:) name:@"getPhotoNotification" object:nil];
}
- (void)viewDidUnload {
[super viewDidUnload];
// Unsubscribe from notifications
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"getPhotoNotification" object:nil];
}
- (void)onGetPhoto:(NSNotification *)notification {
...
}
in your completion block
[[NSNotificationCenter defaultCenter] postNotificationName:@"getPhotoNotification" object:self userInfo:userInfo];
With your photo in userInfo.