Detect parent operation cancellation in download operation completion block

Sebastian Rehnby · Sebastian Rehnby · commit d57b92cd0e85 · 2013-02-26T12:08:55.000+01:00
diff --git a/SDWebImage/SDWebImageManager.m b/SDWebImage/SDWebImageManager.m
@@ -76,6 +76,7 @@ - (NSString *)cacheKeyForURL:(NSURL *)url
     }
 
     __block SDWebImageCombinedOperation *operation = SDWebImageCombinedOperation.new;
+    __weak SDWebImageCombinedOperation *weakOperation = operation;
     
     if (!url || !completedBlock || (!(options & SDWebImageRetryFailed) && [self.failedURLs containsObject:url]))
     {
@@ -108,7 +109,11 @@ - (NSString *)cacheKeyForURL:(NSURL *)url
             if (options & SDWebImageProgressiveDownload) downloaderOptions |= SDWebImageDownloaderProgressiveDownload;
             __block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:progressBlock completed:^(UIImage *downloadedImage, NSData *data, NSError *error, BOOL finished)
             {
-                if (error)
+                if (weakOperation.cancelled)
+                {
+                    completedBlock(nil, nil, SDImageCacheTypeNone, finished);
+                }
+                else if (error)
                 {
                     completedBlock(nil, error, SDImageCacheTypeNone, finished);
 

Original file line number	Diff line number	Diff line change
`@@ -76,6 +76,7 @@ - (NSString )cacheKeyForURL:(NSURL )url`
`76`	`76`	`}`
`77`	`77`
`78`	`78`	`__block SDWebImageCombinedOperation *operation = SDWebImageCombinedOperation.new;`
	`79`	`+ __weak SDWebImageCombinedOperation *weakOperation = operation;`
`79`	`80`
`80`	`81`	`if (!url \|\| !completedBlock \|\| (!(options & SDWebImageRetryFailed) && [self.failedURLs containsObject:url]))`
`81`	`82`	`{`
`@@ -108,7 +109,11 @@ - (NSString )cacheKeyForURL:(NSURL )url`
`108`	`109`	`if (options & SDWebImageProgressiveDownload) downloaderOptions \|= SDWebImageDownloaderProgressiveDownload;`
`109`	`110`	`__block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:progressBlock completed:^(UIImage downloadedImage, NSData data, NSError *error, BOOL finished)`
`110`	`111`	`{`
`111`		`- if (error)`
	`112`	`+ if (weakOperation.cancelled)`
	`113`	`+ {`
	`114`	`+ completedBlock(nil, nil, SDImageCacheTypeNone, finished);`
	`115`	`+ }`
	`116`	`+ else if (error)`
`112`	`117`	`{`
`113`	`118`	`completedBlock(nil, error, SDImageCacheTypeNone, finished);`
`114`	`119`