Filtering out irrelevant choices from Context

[ajstanley]

I've always (well, not always, I used to have a real life) been troubled by the choices we're given under the Derivative Reaction in Contexts - we're given many many illegal or illogical choices.

I've got a filter that only shows actions that are in the family of AbstractGenerateDerivative which takes us from around twenty-two choices (remove content from front page as a derivative??) to about seven choices, all of which actually make derivatives.

I can put in a pull request if this seems like a good idea to others as well.

[whikloj]

Does this affect all Contexts or just specific ones as I'm not sure we'd want to restrict the normal use of Context for other things on someone's site. However being able to add a filter to a Context seems like great extension to Drupal regardless of Islandora.

[ajstanley]

All this affects is what Actions can be selected when you've chosen Derivative as a Reaction.

[dannylamb]

@ajstanley Can haz PR?