You are well acquainted with Joomla! CMS and XML.
We export newspaper articles from InDesign as an xml-file that we need to import to Joomla. Each page has a separate xml-file, and each file import should produce a Joomla content item.
The Joomla Backend Import GUI should have
> three upload-fields, one for the xml file and two for images related to the xml file.
> a button “Create new content item”, which when clicked, opens the normal Joomla “Create new content item” window, with the imported content and image, ready to be edited if needed. An alternative is that the button imports, creates and saves in one step, so you need to open the content item if you want to edit, but I think the first is preferable.
The xml-export is done with SCOOP eXport InDesign Plugin. File example is attached.