Question

I’m VERY new to Objective C and iOS development (like 5 hours new :-). I’ve got some code that calls an API to authenticate a user and returns a simple OK or FAIL. I can get the result to write to the console but what I need to do is get that result as part of my IBAction.

Here’s the IBAction code:

- (IBAction) authenticateUser
{
    [txtEmail resignFirstResponder];
    [txtPassword resignFirstResponder];

    [self performAuthentication];

    if (authResult == @"OK")

What I need is for authResult to be the JSON result (OK or FAIL). Here is the code that gets the result:

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    [connection release];

    NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
    NSLog(@"%@", responseString);
    [responseData release];

    NSMutableDictionary *jsonResult = [responseString JSONValue];
        if (jsonResult != nil) 
            {
                NSString *jsonResponse = [jsonResult objectForKey:@"Result"];
                NSLog(@"%@", jsonResponse);
            }
}

Thank you so much for any help and sorry if I’m missing something obvious!

Answer 1

I’m a little confused as to what’s going on here… it looks like your -performAuthentication method must start an asynchronous network request via NSURLConnection, and your connection’s delegate’s -connectionDidFinishLoading: gets to determine the result of the request. So good so far? But your -authenticateUser method expects authResult to be determined as soon as -performAuthentication returns. If the network request is asynchronous, that’s not going to happen. If I’m following you, I think you need to do the following:

1. Fix up -connectionDidFinishLoading: so that it actually sets authResult based on the Result value in jsonResponse. I’m sure you’d get around to this at some point anyway.
2. Change -authenticateUser such that it doesn’t expect to have an answer immediately. You’ve got to give the network request a chance to do its thing.
3. Add another method, possibly called -authenticationDidFinish or something along those lines. Everything currently in -authenticateUser from the ‘if (authResult…’ to the end goes in this new method.
4. Call the new method from -connectionDidFinishLoading:.

5. Fix your string comparison. If you want to compare two strings in Cocoa, you say (for example):

   if ([authResult isEqualToString:@”OK”) { }