Is it possible to create a page anchor type functionality within the portal? And if yes, could it be made so that the user of the portal will be able to customise where and how the page anchors work (preferably within a rich text editor)? Sorry if it sounds a bit vague but that's currently how I can explain it. Any answer will appreciated especially if the solution can be applied to another type of functionality,; e.g. say collapsible panel widget within html body (in rich text editor)
See forum, anchors are not really the way to go in a Mendix app.
The appstore has a collapsible panel.