Improve the "replacing and deleting file" experience

[mjordan]

This issue comes out of #1208, which was about documenting how replacing and removing files and media works. In both cases as described below, the file and its metadata are removed from Drupal but persist in Fedora.

This issue suggests how we could implement a UI for replacing and removing files and media that is consistent with users' reasonable expectations (i.e., from both Drupal and Fedora). Any UI for also acting on resources in Fedora should take account for the case where Fedora is not present in the Islandora stack bento by not showing UI elements that purge content from Fedora.

Replacing a file

Currently, if you want to replace a file using the "Remove" button in the file's media entity, the replaced file is removed from the media in Drupal, but is not removed from Fedora.

It would be useful to be able to choose whether the replaced file is retained in Fedora, whether it is entirely expunged, or whether a new version of the file and its metadata are created, as illustrated here:

Deleting a file

Similarly, for media deleted from Drupal at http://localhost:8000/media/X/delete, the binary and its metadata persist in Fedora. The only way I've found of verifiably deleting a file and its metadata is to run the "Delete media and file(s) action" in the general media list (http://localhost:8000/admin/content/media).

It should be possible to add an option to this form that executes the code in the "Delete media and file(s) action" so that the user doesn't have to go to http://localhost:8000/admin/content media to actually delete a file and its media but instead can do it closer to the node the file is associated with. For example:

[wgilling]

Should there also be a "Default purge action when deleting" checkbox at the Islandora | Core Settings? or even to control these defaults per content-type -- of course, the default action could be overridden at the node/delete stage.

[seth-shaw-unlv]

If the setting was part of the widget it would set per media type.

[skaught]

Original ask here:

• "checbox option to delete this and Purge 'fedora' as well; OR create NEW VERSION"
• Config Delete screen: add option to purge.
  Certainly in Drupal the flow for deleting the Media Entity this way would normally not remove the file. As we are additionally talking around the use of 'Fedora' as a File System micro-service to store the media aid the persistence of these files (library content)

The media could also be linked within content in other wise too. Content Revision and any workflow also would have fallout around this.

A general mention: Entity Delete related hooks would be better off to look. Again, purpose & persistance of content/media, revision & workflow should be considered