I have a proprietary plugin that creates a metabox on the edit-post page. When the data managed by the plugin is edited and the user navigates away then we would like the user to be prompted as Wordpress (or is it TinyMCE?) does now when the body of the article is edited. Ideally, if the user modifies the metabox and the post content they would be prompted once.
Is there an API which allows us to activate Wordpress' (or is it TinyMCE's?) dirty flag?
I am aware of this similar question and the answer whcih suggests proxying the beforeunload event.