Document adding stuff to the Appearance > Navigation form in the admin

[jeremyboggs]

Is it possible to append form content to the Navigation form? At first I thought it possible, using the navigation_form hook, but it doesn't appear any of the useful methods in Omeka_Form_Navigation are available. It also seems that it might not get rendered correctly, but I'm guessing I'm just doing it wrong.

[patrickmj]

I think this is a hook we intended to add for the beta release, but didn't quite get there. Once it is in there we'll add documentation on this and the other hooks that fall into the same category