An extension for Sparrow that allows SPImage/SPTexture to load web files, NSData, and asynchronously. (Requires ARC)

SPTexture+Web.h

//
//  SPTexture+Web.h
//  SPTexture+Web
//
//  Created by Shilo White on 10/16/12.
//
//  (Requires Automatic Reference Counting)

#import "SPTexture.h"
#import "SPImage.h"
#import "SPEvent.h"

#define SP_EVENT_TYPE_IMAGE_LOADED @"imageLoaded"
#define SP_EVENT_TYPE_IMAGE_FAILED @"imageFailed"

@interface SPTexture (Web)

- (SPTexture *)initWithContentsOfWebFile:(NSString *)path;
- (SPTexture *)initWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error;
- (SPTexture *)initWithData:(NSData *)data;
+ (SPTexture *)textureWithContentsOfWebFile:(NSString *)path;
+ (SPTexture *)textureWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error;
+ (SPTexture *)textureWithData:(NSData *)data;

@end

@interface SPImage (Web)

- (SPImage *)initWithContentsOfWebFile:(NSString *)path;
- (SPImage *)initWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error;
- (SPImage *)initWithData:(NSData *)data;
- (SPImage *)initWithContentsOfAsyncFile:(NSString *)path;
- (SPImage *)initWithContentsOfAsyncWebFile:(NSString *)path;
+ (SPImage *)imageWithContentsOfWebFile:(NSString *)path;
+ (SPImage *)imageWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error;
+ (SPImage *)imageWithData:(NSData *)data;
+ (SPImage *)imageWithContentsOfAsyncFile:(NSString *)path;
+ (SPImage *)imageWithContentsOfAsyncWebFile:(NSString *)path;

@end

@interface SPImageEvent : SPEvent

- (SPImageEvent *)initWithType:(NSString*)type bubbles:(BOOL)bubbles error:(NSError *)error;
+ (SPImageEvent *)imageEventWithType:(NSString*)type bubbles:(BOOL)bubbles error:(NSError *)error;

@property (nonatomic, readonly) NSError *error;

@end

SPTexture+Web.m

//
//  SPTexture+Web.m
//  SPTexture+Web
//
//  Created by Shilo White on 10/16/12.
//
//  (Requires Automatic Reference Counting)

#import "SPTexture+Web.h"
#import <objc/runtime.h>

#define ASYNC_TIMEOUT 60.0f
#define DEFAULT_CAPACITY 102400

@implementation SPTexture (Web)

- (SPTexture *)initWithContentsOfWebFile:(NSString *)path
{
    NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:path]];
    return [self initWithData:data];
}

- (SPTexture *)initWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error
{
    NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:path] options:options error:error];
    return [self initWithData:data];
}

- (SPTexture *)initWithData:(NSData *)data
{
    return [self initWithContentsOfImage:[UIImage imageWithData:data]];
}

+ (SPTexture *)textureWithContentsOfWebFile:(NSString *)path
{
    return [[self alloc] initWithContentsOfWebFile:path];
}

+ (SPTexture *)textureWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error
{
    return [[self alloc] initWithContentsOfWebFile:path options:options error:error];
}

+ (SPTexture *)textureWithData:(NSData *)data
{
    return [[self alloc] initWithData:data];
}

@end

@interface SPImage (WebPrivate)

@property (nonatomic, strong) NSURLConnection *connection;
@property (nonatomic, strong) NSMutableData *data;

@end

@implementation SPImage (WebPrivate)

- (void)setConnection:(NSURLConnection *)connection
{
    objc_setAssociatedObject(self, (__bridge const void *)@"connection", connection, OBJC_ASSOCIATION_RETAIN);
}

- (NSURLConnection *)connection
{
    return objc_getAssociatedObject(self, (__bridge const void *)@"connection");
}

- (void)setData:(NSMutableData *)data
{
    objc_setAssociatedObject(self, (__bridge const void *)@"data", data, OBJC_ASSOCIATION_RETAIN);
}

- (NSMutableData *)data
{
    return objc_getAssociatedObject(self, (__bridge const void *)@"data");
}

@end

@implementation SPImage (Web)

- (SPImage *)initWithContentsOfWebFile:(NSString *)path
{
    SPTexture *texture = [SPTexture textureWithContentsOfWebFile:path];
    return [self initWithTexture:texture];
}

- (SPImage *)initWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error
{
    SPTexture *texture = [SPTexture textureWithContentsOfWebFile:path options:options error:error];
    return [self initWithTexture:texture];
}

- (SPImage *)initWithData:(NSData *)data
{
    SPTexture *texture = [SPTexture textureWithData:data];
    return [self initWithTexture:texture];
}

- (SPImage *)initWithContentsOfAsyncFile:(NSString *)path
{
    if ((self = [super init]))
    {
        NSString *fullPath = [SPUtils absolutePathToFile:path withScaleFactor:[SPStage contentScaleFactor]];
        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL fileURLWithPath:fullPath] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:ASYNC_TIMEOUT];
        self.connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    }
	return self;
}

- (SPImage *)initWithContentsOfAsyncWebFile:(NSString *)path
{
    if ((self = [super init]))
    {
        NSURL *url = [NSURL URLWithString:path];
        if (!url.scheme) url = [NSURL URLWithString:[@"http://" stringByAppendingString:path]];
        NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:ASYNC_TIMEOUT];
        self.connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    }
	return self;
}

+ (SPImage *)imageWithContentsOfWebFile:(NSString *)path
{
    return [[self alloc] initWithContentsOfWebFile:path];
}

+ (SPImage *)imageWithContentsOfWebFile:(NSString *)path options:(NSDataReadingOptions)options error:(NSError *__autoreleasing *)error
{
    return [[self alloc] initWithContentsOfWebFile:path options:options error:error];
}

+ (SPImage *)imageWithData:(NSData *)data
{
    return [[self alloc] initWithData:data];
}

+ (SPImage *)imageWithContentsOfAsyncFile:(NSString *)path
{
    return [[self alloc] initWithContentsOfAsyncFile:path];
}

+ (SPImage *)imageWithContentsOfAsyncWebFile:(NSString *)path
{
    return [[self alloc] initWithContentsOfAsyncWebFile:path];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    long long capacity = (response.expectedContentLength != NSURLResponseUnknownLength) ? response.expectedContentLength : DEFAULT_CAPACITY;
    self.data = [[NSMutableData alloc] initWithCapacity:capacity];
}

- (void)connection:(NSURLConnection *)urlConnection didReceiveData:(NSData *)data
{
    [self.data appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    SPTexture *texture = [SPTexture textureWithData:self.data];
	(void)[self initWithTexture:texture];
    
    self.data = nil;
    self.connection = nil;
    
    
    SPEvent *loadedEvent = [SPEvent eventWithType:SP_EVENT_TYPE_IMAGE_LOADED];
    [self dispatchEvent:loadedEvent];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    SPImageEvent *failedImageEvent = [SPImageEvent imageEventWithType:SP_EVENT_TYPE_IMAGE_FAILED bubbles:NO error:error];
    [self dispatchEvent:failedImageEvent];
    
    self.data = nil;
    self.connection = nil;
}

@end

@implementation SPImageEvent
{
    NSError *_error;
}

@synthesize error = _error;

- (SPImageEvent *)initWithType:(NSString*)type bubbles:(BOOL)bubbles error:(NSError *)error
{
    if (self = [super initWithType:type bubbles:bubbles])
    {
        _error = error;
    }
    return self;
}

+ (SPImageEvent *)imageEventWithType:(NSString*)type bubbles:(BOOL)bubbles error:(NSError *)error
{
    return [[self alloc] initWithType:type bubbles:bubbles error:error];
}

@end