I have a document library set up with a number of content types. I want to set up an event in a particular metadata field so that I can capture when the user selects to edit that field and show a modal dialog that can perform a search in an external system using API calls.
Is that possible? What methods are available (if any) to identify and hang an event from this field? Also, is there a way to do this that will also work from within the SharePoint apps on iOS and Android?