We have added more Grails-specific completion in IntelliJ Idea X. In particular, IntelliJ IDEA now knows about action and controller names in most places where they can appear.
In the ‘controller’ and ‘action’ attributes of some GSP tags:
In some method calls (e.g. redirect(…), render(…), chain(…)):
In the URL mappings configuration:
Needless to say, find usages and rename work for such references as well.