I'd like to create a custom field that allows other developers, QA testers, etc. to specify an external issue ID that automatically creates a link that incorporates the field value. We're currently still using a separate bug tracker for our QA team, although we're migrating away from it.
I am only able to select from a limited subset of renderers for a custom field. Is there a way to create a new custom renderer that will let me build a URL based on the field's value as part of the renderer?