Collection metadata

Is it possible to add a metadata field to the Collection Details? If so, how can I do this?

It is possible, but would require making a plugin. Currently, the Omeka data model provides limited collection-level description. It has the name of the collection and a description. To add more metadata you could write a plugin that hooks into the admin_append_to_collections_form to add some more form elements, and then save that data by listening to the after_save_form_record hook for the collection records.

It might also be possible to modify the core code to make the Collection model use the ActAsElementText mixin, so that it would have element data like the Item and File models, but such core changes would have be added to the roadmap of Omeka.

If you interested in proposing new features, add a new post to the Feature Requests forum. Also, consider joining the Omeka Developer Mailing List to discuss plugin development: