Good pattern for Internet requests with Grand Central Dispatch?

Question

I\'m currently using synchronous ASIHTTPRequest with GCD queues to download data from the Internet, then parse the response data with JSONKit. What do you think about this patte

Answer 1

So you replaced this

- (void)doDownload {
    NSURL *url = [NSURL URLWithString:@"http://foobar.com"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    connection = [[NSURLConnection alloc] initWithRequest:aURLRequest delegate:self];
    receivedData = [[NSMutableData data] retain];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [_receivedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    NSArray *array = [_receivedData objectFromJSONDataWithParseOptions:JKParseOptionLooseUnicode];
    callbackBlock(array);       
}

with this -

- (void)doDownload {
    NSURL *url = [NSURL URLWithString:@"http://foobar.com"];
    ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    dispatch_async(queue, ^(void) {
        [request startSynchronous];
        NSArray *array = [[request responseData] objectFromJSONDataWithParseOptions:JKParseOptionLooseUnicode];

        // Callback on the main queue to update UI.
        dispatch_async(dispatch_get_main_queue(), ^(void) {
            callbackBlock(array);
        });
    });
}

and 10,000+ lines of code from ASIHTTPRequest.

What has it got you?

NSURLConnection is fully asynchronous, uses GCD, caches, automatic zip/unzip, etc, etc..

For that reason, and going solely on the (possibly incomplete) information you provided, i'd say that it was a really awful piece of code.

Of course, context is everything - and you may have a really, really, really good reason for reimplementing the already existing functionality of Library code provided by Apple.