Overriding default initializer when using storyboards (Constructor Dependency Injection)

Question

The typical approach taken when one needs to pass/share variables among view controllers (using storyboards) is to grab a reference to the target viewcontroller in prepareForSegue: method and use property injection like so:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:@"Segue_Name"])
    {
        // Get reference to the target view controller (optional casting)
        DestinationViewController *vc = (DestinationViewController *)segue.destinationViewController;

        // Pass any objects/properties
        vc.whateverObject = object;
}

}

The problem with this approach (as I see it in the context of the domain I'm dealing with on a current project) is that the dependency on the object being passed/injected is not explicit.

Though this kind of freedom (being able to inject dependencies after initialization) is welcome in some use cases where flexibility is required, most of the time I prefer the feeling of safety constructor injection provides.

Especially in a language like objective-c where passing around and sending messages to nil is allowed/common, hunting bugs where I forgot to set a property at the right point is tiresome even with unit tests to back me up.

What I'd like to know is if there is a way to use a custom initializer, one I could provide with as many arguments/dependencies I need.

Is there a way I can manually control the initialization of segue.destinationViewController ?

Answer 1

As long as I know you can not. If you want your custom initialization you have to do it without segues - using init , store your DestinationViewController manually and do whatever you need to do with it pushViewController or presentViewController .

Another drawback of using segue is that DestinationViewController will be recreated every time.