Added failureBlock to allow proper handing of errors situations

jakemarsh · Jan 7, 2013 · 1af09be · 1af09be
1 parent a09d871
commit 1af09be
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Showing 4 changed files with 67 additions and 28 deletions.
diff --git a/JMImageCache.h b/JMImageCache.h
@@ -22,8 +22,8 @@
 
 + (JMImageCache *) sharedCache;
 
-- (void) imageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion;
-- (void) imageForURL:(NSURL *)url completionBlock:(void (^)(UIImage *image))completion;
+- (void) imageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure;
+- (void) imageForURL:(NSURL *)url completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure;
 
 - (UIImage *) cachedImageForKey:(NSString *)key;
 - (UIImage *) cachedImageForURL:(NSURL *)url;

diff --git a/JMImageCache.m b/JMImageCache.m
@@ -31,7 +31,7 @@ @interface JMImageCache ()
 
 @property (strong, nonatomic) NSOperationQueue *diskOperationQueue;
 
-- (void) _downloadAndWriteImageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion;
+- (void) _downloadAndWriteImageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure;
 
 @end
 
@@ -60,33 +60,58 @@ - (id) init {
  return self;
 }
 
-- (void) _downloadAndWriteImageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion {
+- (void) _downloadAndWriteImageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure
+{
  if (!key && !url) return;
 
  if (!key) {
  key = keyForURL(url);
  }
 
  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
- NSData *data = [NSData dataWithContentsOfURL:url];
- UIImage *i = [[UIImage alloc] initWithData:data];
- // stop process if the method could not initialize the image from the specified data
- if (!i) return;
 
- NSString *cachePath = cachePathForKey(key);
- NSInvocation *writeInvocation = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:@selector(writeData:toPath:)]];
-
- [writeInvocation setTarget:self];
- [writeInvocation setSelector:@selector(writeData:toPath:)];
- [writeInvocation setArgument:&data atIndex:2];
- [writeInvocation setArgument:&cachePath atIndex:3];
-
- [self performDiskWriteOperation:writeInvocation];
- [self setImage:i forKey:key];
-
- dispatch_async(dispatch_get_main_queue(), ^{
- if(completion) completion(i);
- });
+ NSURLRequest* request = [NSURLRequest requestWithURL:url];
+ NSURLResponse* response = nil;
+ NSError* error = nil;
+ NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
+
+ if (error)
+ {
+ dispatch_async(dispatch_get_main_queue(), ^{
+
+ if(failure) failure(request, response, error);
+ });
+ return;
+ }
+
+ UIImage *i = [[UIImage alloc] initWithData:data];
+ if (!i)
+ {
+ NSMutableDictionary *errorDetail = [NSMutableDictionary dictionary];
+ [errorDetail setValue:[NSString stringWithFormat:@"Failed to init image with data from for URL: %@", url] forKey:NSLocalizedDescriptionKey];
+ NSError* error = [NSError errorWithDomain:@"JMImageCacheErrorDomain" code:1 userInfo:errorDetail];
+ dispatch_async(dispatch_get_main_queue(), ^{
+
+ if(failure) failure(request, response, error);
+ });
+ }
+ else
+ {
+ NSString *cachePath = cachePathForKey(key);
+ NSInvocation *writeInvocation = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:@selector(writeData:toPath:)]];
+
+ [writeInvocation setTarget:self];
+ [writeInvocation setSelector:@selector(writeData:toPath:)];
+ [writeInvocation setArgument:&data atIndex:2];
+ [writeInvocation setArgument:&cachePath atIndex:3];
+
+ [self performDiskWriteOperation:writeInvocation];
+ [self setImage:i forKey:key];
+
+ dispatch_async(dispatch_get_main_queue(), ^{
+ if(completion) completion(i);
+ });
+ }
  });
 }
 
@@ -131,19 +156,19 @@ - (void) removeObjectForKey:(id)key {
 #pragma mark -
 #pragma mark Getter Methods
 
-- (void) imageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion {
+- (void) imageForURL:(NSURL *)url key:(NSString *)key completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure{
 
  UIImage *i = [self cachedImageForKey:key];
 
  if(i) {
  if(completion) completion(i);
  } else {
- [self _downloadAndWriteImageForURL:url key:key completionBlock:completion];
+ [self _downloadAndWriteImageForURL:url key:key completionBlock:completion failureBlock:failure];
  }
 }
 
-- (void) imageForURL:(NSURL *)url completionBlock:(void (^)(UIImage *image))completion {
- [self imageForURL:url key:keyForURL(url) completionBlock:completion];
+- (void) imageForURL:(NSURL *)url completionBlock:(void (^)(UIImage *image))completion failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure{
+ [self imageForURL:url key:keyForURL(url) completionBlock:completion failureBlock:(failure)];
 }
 
 - (UIImage *) cachedImageForKey:(NSString *)key {
@@ -185,7 +210,8 @@ - (UIImage *) imageForURL:(NSURL *)url key:(NSString*)key delegate:(id<JMImageCa
  [d cache:self didDownloadImage:image forURL:url key:key];
  }
  }
- }];
+ }
+ failureBlock:nil];
  }
 
  return nil;

diff --git a/UIImageView+JMImageCache.h b/UIImageView+JMImageCache.h
@@ -13,7 +13,10 @@
 - (void) setImageWithURL:(NSURL *)url;
 - (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage;
 - (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *))completionBlock;
+- (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *))completionBlock failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure;
 - (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage;
 - (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *image))completionBlock;
+- (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *image))completionBlock failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failure;
+
 
 @end
diff --git a/UIImageView+JMImageCache.m b/UIImageView+JMImageCache.m
@@ -44,12 +44,18 @@ - (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage {
  [self setImageWithURL:url key:nil placeholder:placeholderImage];
 }
 - (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *))completionBlock {
- [self setImageWithURL:url key:nil placeholder:placeholderImage completionBlock:completionBlock];
+ [self setImageWithURL:url key:nil placeholder:placeholderImage completionBlock:completionBlock failureBlock:nil];
+}
+- (void) setImageWithURL:(NSURL *)url placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *))completionBlock failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failureBlock {
+ [self setImageWithURL:url key:nil placeholder:placeholderImage completionBlock:completionBlock failureBlock:failureBlock];
 }
 - (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage {
  [self setImageWithURL:url key:key placeholder:placeholderImage completionBlock:nil];
 }
 - (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *image))completionBlock {
+ [self setImageWithURL:url key:key placeholder:placeholderImage completionBlock:completionBlock];
+}
+- (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)placeholderImage completionBlock:(void (^)(UIImage *image))completionBlock failureBlock:(void (^)(NSURLRequest *request, NSURLResponse *response, NSError* error))failureBlock{
  self.jm_imageURL = url;
  self.image = placeholderImage;
 
@@ -101,6 +107,10 @@ - (void) setImageWithURL:(NSURL *)url key:(NSString*)key placeholder:(UIImage *)
  if (completionBlock) completionBlock(image);
  });
  }
+ }
+ failureBlock:^(NSURLRequest *request, NSURLResponse *response, NSError* error)
+ {
+ if (failureBlock) failureBlock(request, response, error);
  }];
  }
  });