NSURLHandle provides an interface for uploading and downloading data to and from a resource specified by an NSURL. NSURLHandle actually offloads much of this work to subclasses that implement NSURLHandle's interface to work with various schemes.

@interface NSURLHandle : NSObject
// Class Methods
+ (Class)URLHandleClassForURL:(NSURL *)anURL;
+ (NSURLHandle *)cachedHandleForURL:(NSURL *)anURL;
+ (BOOL)canInitWithURL:(NSURL *)anURL;
+ (void)registerURLHandleClass:(Class)anURLHandleSubclass;
// Instance Methods
- (void)addClient:(id <NSURLHandleClient>)client;
- (id) initWithURL:(NSURL *)anURL cached:(BOOL)willCache;
- (NSData *)availableResourceData;
- (void)backgroundLoadDidFailWithReason:(NSString *)reason;
- (void)beginLoadInBackground;
- (void)cancelLoadInBackground;
- (void)didLoadBytes:(NSData *)newBytes loadComplete:(BOOL)yorn;
- (void)endLoadInBackground;
- (NSString *)failureReason;
- (void)flushCachedData;
- (void)loadInBackground;
- (NSData *)loadInForeground;
- (id)propertyForKey:(NSString *)propertyKey;
- (id)propertyForKeyIfAvailable:(NSString *)propertyKey;
- (void)removeClient:(id <NSURLHandleClient>)client;
- (NSData *)resourceData;
- (NSURLHandleStatus)status;
- (BOOL)writeData:(NSData *)data;
- (BOOL)writeProperty:(id)propertyValue forKey:(NSString *)propertyKey;