Question

I am starting to work with the Three20 library and created a UIButton using the following code:

self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:@"Add New" 
                                                                           style:UIBarButtonItemStyleBordered
                                                                          target:@"tt://samples/new"
                                                                          action:nil] autorelease];

When the user touches the button, I would like to push an instance of NewSampleViewController onto the nav. I have added the following in my app delegate’s -didFinishLaunchingWithOptions method:

[map from:@"tt://samples/new" toViewController:[NewSampleViewController class]];

As it stands, when the button is touched, nothing happens at all. Nothing happens on the device and I don’t see any logging going on in the console.

What have I done wrong or missed here?

Thanks!

Answer 1

Unless there is something magical I haven’t discovered yet, I don’t think you’ve wired your button delegation correctly. It looks like you’ve told the button that the string @”tt://samples/new” is the object that receives the press event and you want it to send no message (call no method / nil).

Create a method in the view controller with the button, such as this:

- (void)addButtonPressed:(id)sender{
  TTURLAction *urlAction = [TTURLAction actionWithURLPath:@"tt://samples/new"];
  [[TTNavigator navigator] openURLAction:urlAction];
}

Then replace your button init with this:

    self.navigationItem.rightBarButtonItem = 
          [[[UIBarButtonItem alloc] initWithTitle:@"Add New" 
                                            style:UIBarButtonItemStyleBordered
                                           target:self
                                           action:@selector(addButtonPressed:)]
           autorelease];

This will invoke the TTNavigator singleton instance to open the action created with the string path provided. The button needs to be handled by a button delegate and self, your view controller, is perfectly appropriate for that. The handler method then causes a three2 navigation using a path. If you’ve got things wired correctly in your appDelegate, three20 will create and push the view controller you mapped.
Hope that helps.