[Support Question] Navigation stack with bar about coconutkit

[defagos]

Conceptually, a CoconutKit-based navigation view controller can be obtained by subclassing HLSPlaceholderViewController to embeds an HLSStackController instance and a navigation bar at the top. When the view controller displayed by the stack changes, the navigation bar can be updated by the HLSPlaceholderViewController accordingly (most probably using the child view controller -navigationItem information).

If I were to implement a CoconutKit-based navigation view controller, I would do things differently, though. A direct HLSPlaceholderViewController subclass interface would namely be polluted by the parent class interface, which I strive to avoid. To solve this issue, I would most definitely build my implementation on the HLSContainerStack class. But if you do not need this custom navigation controller to be easily reused in another project, this might be overkill and you should simply inherit from HLSPlaceholderViewController.

[mmmilo]

would namely be polluted by the parent class interface

Did you mean because just using HLSPlaceholderViewController on its own looks too heavy? Perhaps I'm confused by what you mean, but HLSPlaceholderViewController looks fairly lightweight (just a stack per each placeholder).

Of course the navigationItem per each push is generated automatically so doesn't need to expose a "push" on it's own.

Thanks for the input!

[defagos]

If you want to implement a custom navigation controller using existing CoconutKit containers, you should start by subclassing HLSPlaceholderViewController (with two views, one navigation bar at the top, and one placeholder view below, in which a stack controller will be displayed). But doing so you will inherit all the methods of HLSPlaceholderViewController, and those do not make sense for a navigation controller, which essentially requires push and pop methods. In fact, there is no is-a relationship between a navigation controller and a placeholder view controller.

This can be done, of course, but the resulting class interface will look ugly. If all you need is a quick solution for a single project, this is still a viable option, though. But if you start implementing custom navigation controllers this way all the time, you should consider using HLSContainerStack instead. This is the best way to design and implement a navigation controller class you and others can easily reuse

[mmmilo]

Understood, thanks for the clear answer!