Question

I have a little Mac application which should be able to post Data to my web server which saves the data in a database. Now that’s the Code I have now:

NSData *postData = [urlString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:@"http://..."]];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];
    NSURLConnection * connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

    if (connection) NSLog(@"Done");

And it works fine. But now I want to check whether the data was correct (and stored in the database) or something (like eMail) is wrong. The PHP file prints e.g. “email incorrect” out if the E-Mail is not correct.
But how can I fetch this data (which PHP prints out) in Xcode that the App knows whether it was successful or not?

Thanks for answers!

Answer 1

Implement the delegate method for the NSURLConnection,

– (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response.

This method is called by the app when the request finishes. You can access response data using the ‘response’ parameter.

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;

Then just convert the ‘data’ parameter into a string using:

NSString *responseString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

Then you can search the response for whatever string you want, e.g., “email incorrect”.

PS: I generally don’t use NSURLConnection/NSURLRequest for HTTP requests, I’d recommend you check out ASIHTTPRequest for really simple HTTP requests/connections.

Hope this helps.