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iOS Build a Self-Destructing Message iPhone App Using Parse.com as a Backend and Adding Users Logging In and Logging Out

Posted by Omar Ghias
Omar Ghias
1,837 Points

Objective-C Block Help

Can someone please explain why this line of code doesn't work for step #3? Thanks!

[PFUser logInWithUsernameInBackground:"@test" password:@"test"  block:(^loginHandler)(PFUser *user, NSError *error)];

2 Answers

Keith Kowalski
Keith Kowalski
9,302 Points

I have submitted this exact answer and it still claims it is wrong. I had submitted this answer and thought it was just me doing something off, but now, I am lost!

I'll include the provided TreeHouse code below, along with my answer:

#import "LoginViewController.h"
#import "UIAlertView.h"
#import <Parse/Parse.h>

@implementation LoginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (IBAction)login:(id)sender {
    // This is an example of how to declare a block named loginHandler. It starts with a
    // return type, then the name of the block with a special syntax for naming. The next
    // set of parentheses hold the parameters and their types. Then assigning the block 
    // on the right side looks just like how we defined it in the video (carat with the
    // same parameters in parentheses).
    void (^loginHandler)(PFUser *user, NSError *error) = ^(PFUser *user, NSError *error) {
        if (error) {
            UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Sorry!"
                                                                message:@"Error logging in."
                                                               delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [alertView show];
        }
        else {
            [PFUser navigationController popToRootViewControllerAnimated:YES];
        }
    };

    // Add your code below!

    [PFUser logInWithUsernameInBackground:@"test" password:@"test" block:loginHandler];
}

@end
Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

The challenge states:Use @"test" as the 1st and 2nd parameters. Then pass in loginHandler as the 3rd parameter.

all you have to do is pass in the name of the block

[PFUser logInWithUsernameInBackground:@"test" password: @"test" block:loginHandler];