Notes on using NSURLProtocol

gistfile1.m

// The basics:
// - Write your own NSURLProtocol subclass and register it.
// - Override the 5 required methods
// - Kick off download or cache fetch during |startLoading|
// - Update self.client with progress/completion/failure notifications.

// UIWebView will download requests concurrently via NSURLProtocol.
// If you use the typical NSURLCache hook to download content, you're
// stuck with serial downloads.

// Register once. +load is a good time.
[NSURLProtocol registerClass:[MyURLProtocol class]];

// iOS will call this selector on all registered URL
// protocols in reverse-registration order.
// Here, decide whether it's a request you want to handle.
+ (BOOL)canInitWithRequest:(NSURLRequest *)request;

// Also implement:
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request;
+ (BOOL)requestIsCacheEquivalent:(NSURLRequest *)a
                       toRequest:(NSURLRequest *)b;

- (void)startLoading {
  NSData *data = // Get cached data
  if (data) {
    [[self client] URLProtocol:self didLoadData:data];
    [[self client] URLProtocolDidFinishLoading:self];
  } else {
    // Create our GTMHTTPFetcher *fetcher_
    [fetcher_ beginFetchWithCompletionHandler:^(/*...*/) {
      // Grab download off disk, or cache, etc... then:
      [[self client] URLProtocol:self didLoadData:data];
      [[self client] URLProtocolDidFinishLoading:self];
    }];
  }
}

// Use [self client] NSURLProtocolClient methods to update download state/progress.

Hi,

I´m a absolute Newbe and have no chance.

I'll save the data in a DB. Can you tell me, how to handle this?

[fetcher_ beginFetchWithCompletionHandler:^(/.../) {

// Grab download off disk, or cache, etc... then:

TIA, UlliH