CachedImageView

CachedImageView.m

#import "CachedImageView.h"

#import "Cache.h"

@implementation CachedImageView

- (id)initWithFrame:(CGRect)frame {
  if ((self = [super initWithFrame:frame])) {
    self.contentMode = UIViewContentModeScaleAspectFill;
    self.clipsToBounds = YES;
  }
  return self;
}

- (void)setImageURL:(NSURL *)imageURL {
  _imageURL = imageURL;

  if (_imageURL == nil) {
    [super setImage:nil];
    return;
  }
  
  NSData *data = [Cache objectForCacheKey:[_imageURL absoluteString]];
  if (data) {
    UIImage *image = [UIImage imageWithData:data];
    [super setImage:image];
    return;
  }

  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{

      NSURLRequest *request = [NSURLRequest requestWithURL:_imageURL];
      NSURLSession *session = [NSURLSession sharedSession];
      NSURLSessionDataTask *task = [session dataTaskWithRequest:request
                                              completionHandler:
          ^(NSData *data, NSURLResponse *response, NSError *error) {

              if (!error && [data length] > 0) {
                [Cache cacheObject:data forKey:[_imageURL absoluteString]];

                UIImage *image = [UIImage imageWithData:data];
                dispatch_async(dispatch_get_main_queue(), ^{
                    [super setImage:image];
                });
              }
          }];
    
      [task resume];
  });
}

- (void)reset {
  self.image = nil;
}

@end