Question

I’ve been trying this Twitter api stuff and it’s really confusing…

I keep getting EXC_BAD_ACCESS bad access with the following code… What is the problem here?

NSURL *followingURL = [NSURL URLWithString:@"https://api.twitter.com/1/users/lookup.json"];
// Pass in the parameters (basically '.ids.json?screen_name=[screen_name]')
id fromIntToNum = [NSNumber numberWithInteger: friID];
NSDictionary *parameters = [NSDictionary dictionaryWithObjectsAndKeys:@"159462573", @"user_id", nil];
// Setup the request
twitterRequest = [[TWRequest alloc] initWithURL:followingURL
                                                parameters:parameters
                                             requestMethod:TWRequestMethodGET];
// This is important! Set the account for the request so we can do an authenticated request. Without this you cannot get the followers for private accounts and Twitter may also return an error if you're doing too many requests
[twitterRequest setAccount:theAccount];
// Perform the request for Twitter friends
[twitterRequest performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
    if (error) {
        /*
        // deal with any errors - keep in mind, though you may receive a valid response that contains an error, so you may want to look at the response and ensure no 'error:' key is present in the dictionary
        NSLog(@"%@",error);*/
    } else {
        /*NSError *jsonError = nil;
        // Convert the response into a dictionary
        NSDictionary *twitterGrabbedUserInfo = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONWritingPrettyPrinted error:&jsonError];
        // Grab the Ids that Twitter returned and add them to the dictionary we created earlier
        NSLog(@"%@", [twitterGrabbedUserInfo objectForKey:@"screen_name"]);*/
    }

}];

I separated the line the my code fails on…

What could be causing this Twitter API problem?

The following line causes the crash:::

[twitterRequest performRequestWithHandler:^(NSData *responseData,
                NSHTTPURLResponse *urlResponse, NSError *error) {

I will also sometimes get this error:

[__NSCFNumber credentialForAccount:]: unrecognized 

UPDATE: I commented out the handler and I made TwitterRequest and ivar, but it still crashes…

Answer 1

In your block you look for an error, but if you get one you log it and continue on. You should put an “else” statement in and only proceed if no error.

Why not try to comment out all your code in the handler – don’t do anything – and see if you get the crash. Then try with just the error code. Then try with the JSON serialization, and finally the last line. If you can find the part of the block that is causing the problem that would help.

Also, I suspect that performRequestWithHandler: does not block, but expects you to notify your class within the block that the request is done. If so it means “TWRequest *twitterRequest” should be an ivar or property, and you need to allows for some method to get called when the handler is done. Your crash may be due to ARC reallocating your object while the object is running.

EDIT:
Note that that the TWRequest class description says: “Use the initWithURL:parameters:requestMethod: method to initialize a newly created TWRequest object passing the required property values. ” It says PLURAL properties, meaning more than 1. Could it be that it also expects a “credentialForAccount” property? You have to read the twitter docs to find all the required properties.

EDIT2:
Well, we don’t even know if you get as far as your handler. Put a NSLog there but I suspect its never getting that far. If true this leaves three possibilities:

a) it does’t like the URL (although this seems good)

b) you are missing some parameters it expects

c) id doesn’t like “theAccount” object – is it a valid ACAccount object? Try NSLogging it.

It has to be one of these three things.