include/exclude filter for every selected collection

[gythaogg]

As I was testing PR #1567, I was wondering if it makes sense to allow both include and exclude option for every selected collection...

Say, an ontology has these collections {"original", "commentary", "destroyed", "translation"}

As a user I would like to be able to search for works that are original (include original) and NOT destroyed (exclude destroyed)

[b1rger]

Yeah, that would be great. I think the biggest question is which UI element to use to implement this

[sennierer]

• nicer solution would be a filter widget that allows to switch collections on and of with a button
• easier is to have two filters, one for include and one for excluding the collection

[sennierer]

currently the dropdown for the collections has two states (selected and deselected), lets try to add a third (not selected, selected - check, and exclude - minus)

[sennierer]

similar to

[b1rger]

https://stackoverflow.com/questions/1726096/tri-state-check-box-in-html