RemoteImageView is a easy to use, fast, configurable replacement for UIImageView that handles loading remote pictures.

Features

• iOS 4.3+ compatible (should work on iOS 4.0 without major issues)
• ARC ready
• uses GCD
• Resize & center crop before setting to image
• Disk caching for resized images

How To Install

1. Copy RemoteImageView.h and RemoteImageView.m into your project folder and add them to your project

2. Import RemoteImageView.h :

    #import "RemoteImageView.h"
   

3. You're ready to use !

Basic Usage

RemoteImagteView is build as a UIIImageView compatible replacement.

RemoteImageView *imageView = [[RemoteImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
imageView.imageURL = [NSURL URLWithString:@"http://farm9.staticflickr.com/8025/7260272478_95198c7452_z.jpg"];
[self.view addSubview:imageView];

This will create an UIImageView component and start loading the url right away. The result image will be scaled and center cropped :

(Dog Image Credits : stovak on Flickr)

#Options

• resizeImage (BOOL) - default YES. If set to NO the image will not be resized and cropped
• animate (BOOL) - default YES. Animates the alpha of the image from 0 to 1 on load
• ignoreAnimateOnCache (BOOL) - default NO. Doesn't run the display animation if image data comes from cache (example : in a UITableView when scrolling)
• CacheMode (RICacheMode) - default RIDiskCacheMode
  • RIDiskCacheMode - caches all images on disk and loads them from disk on subsequent requests. Cache is persisted between application sessions
  • RIURLCacheMode - uses default NSURLCache for caching. Cache is not persisted between application sessions.
  • RICacheModeNone - uses in memory cache only (NSCache)
• showActivityIndicator (BOOL) - default YES. Shows an centered activity indicator while URL is loading. Conforms to activityIndicatorStyle property.
• activityIndicatorStyle (UIActivityIndicatorViewStyle) - default UIActivityIndicatorViewStyleGray. Style to use for activity indicator shown when showActivityIndicator is set to YES and image is loading.

#Handling result RemoteImageView can let you know when the loading is finished. This is done by passing a complete and error block to the component. The result blocks are always called on the main dispatch queue.

RemoteImageView *imageView = [[RemoteImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
imageView.completeBlock = ^(UIImage *image) {

    NSLog(@"image finished loading : %@", image);
    
};
imageView.errorBlock = ^(NSError *error) {

    NSLog(@"image failed to load with error : %@", error);
    
};
imageView.imageURL = [NSURL URLWithString:@"http://farm9.staticflickr.com/8025/7260272478_95198c7452_z.jpg"];
[self.view addSubview:imageView];

For similar functionality you can use the following convenience method :

RemoteImageView *imageView = [[RemoteImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[imageView loadImageURL:[NSURL URLWithString:@"http://farm9.staticflickr.com/8025/7260272478_95198c7452_z.jpg"] 
      withCompleteBlock:^(UIImage *image) {
      
    NSLog(@"image finished loading : %@", image);
    
}   withErrorBlock:^(NSError *error){

    NSLog(@"image failed to load with error : %@", error);
    
}];
[self.view addSubview:imageView];

#Caching All images loaded by a RemoteImageView instance are saved in the NSCache memory cache and either in the NSURLCache when using the RIURLCacheMode or the disk cache directory when using RIDiskCacheMode You can invalidate the cache by calling (this will clear all caches : disk / URL / memory ) :

[RemoteImageView clearCache];

#Cancel loading You can cancel loading for a specific RemoteImageView instance by calling the instance method cancel :

[myImageView cancel];

Or you can cancel all loading operations in all active RemoteImageView instances by calling the class method cancelAll :

[RemoteImageView cancelAll];

#Default fallback image

If you want to use a default fallback image for requests that have failed you can set it using the setDefaultGlobalImage: class method :

[RemoteImageView setDefaultGlobalImage:[UIImage imageNamed:@"404"]];

You can get the default global image by using the defaultGlobalImage class method :

UIImage *defaultImage = [RemoteImageView defaultGlobalImage];

#Custom Image Resizing You can fully customize the loaded image before displaying it by using the imageResizeBlock property. If the property is not set the default image resize mode is used (scale, crop and center).

Note : This property is ignored if resizeImage is set to NO

Example (let's say you have an UIImage category that implements the resizedImage:(CGSize)size method ) :

RemoteImageView *imageView = [[RemoteImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
imageView.imageResizeBlock = ^(UIImage *input, UIImage **output) {
    UIImage *resized = [input resizedImage:imageView.frame.size];
    *output = resized;
};
imageView.imageURL = [NSURL URLWithString:@"http://farm9.staticflickr.com/8025/7260272478_95198c7452_z.jpg"];
[self.view addSubview:imageView];

#TODO

• smarter disk caching support (follow cache headers, cache large image as well)
• ...