Javascript service to expose current entity context to action based property editors

[andrewmckaskill]

I need a way to make my property editors aware of the current entity that is being manipulated.

My application is a ticket management system. Each ticket progresses through a series of states, but only some transitions are valid (eg. New -> In Progress is valid, In Progress -> New is not).
I have a custom action to "change status", with a property editor for "New State". Currently this editor has to show ALL states and the validation is done server side when the action is submitted to determine if the transition is valid.

If there was a javascript service that exposed the current entity / entities, either as full models or just as ids, then I could create a custom property editor. If the full model is available then the logic could be done client-side. If only the Id is available then the editor could call a server-side API to get the valid transitions for the given record.