In a tabpage GUI Extension, what does the ext:pagetype node do?

Question

I have a GUI Extension adding a Tab (ext:tabpage) to View.

What does the ext:pagetype node do? I have been using Namespace:Name like the following. Are there other options for the value?

<ext:pagetype>RC.TabExtension</ext:pagetype>

Answer 1

It allows you to have a specific JavaScript implementation for that tab.

If you specify the full name of a JavaScript class and it implements the Tridion.Controls.DeckPage interface, it will use that implementation for the tab.

If it's not a class or it doesn't implement the interface, it will just use the default implementation.

(Tabs inherit from Decks, in case you are wondering)