After some 2 years working with Omeka-S installations I would like to share my experience with the lack of linking support for Media entities. And wonder what solutions others have found for this.
I have the impression that Media are, as for linking, not treated as generously as Items and Item Sets.
A situation that now and then causes some modeling problems.
Specifically:
- afaik a Media entity can not be linked to multiple Items, and
- afaik there are no “Media Set” entities to define a collection of Media
For 1. a use case occurs when you have an image, “born digital” so defintely a Media entity I would say, that is a “representation” of e.g. 2 persons. For both persons I have a Item entity in Omeka-S and I would like to link the Media entity to both Items.
Afaik I cannot do this via the standard tools in Omeka-S (and in that way get the o:media property set in the Items).
Case 2 occurred e.g. when I had a document (with a Document Item modeling it) and a pdf (a single Media entity) with some pages ocr-ed on the one hand and a set of hires scans of each page (a set of Media entities).
Of course I want both to be linked to the (document) Item, but there is no (Omeka-S) "builting way to treat the set of scans as a single “Media Set”.
In both cases my solution was to resort to creating an extra, intermediate, Item entity.
In case 1 I made a Picture class Item and “standardly” linked(o:media) the image Media to this Picture Item.
Next the Picture Item is then manually linked (dc:hasFormat) to each of the Person Item s, functioning as an “intermediate” to the image Media.
In case 2 I made a Scanset Item and “standardly” linked(o:media) all scan image Media to that. The Document Item then gets the pdf Media "standardly "linked (o:media) and the ScanSet Item “manually” linked (dc:hasformat) as intermediate Entity to the scan image Media.
Clearly these solutions are suboptimal, because, given an Item you cannot get to the “reperesentations” anymore by simple following the o:media property. And thus the default rendering methods is site pages, the IIIF module etc. dont work automatically anymore. I did not try to manually set the o:media property in the metadata because I guess that would confuse Omeka-S, though it would solve at least use case 1 
My two questions:
- Would it be benificially/doable to provide support for the some extra linking facilities for Media in a next release of Omeka_S?
- has anyone come up with better solutions for my problematic use cases?
Wish to hear from you,
John