Environment : ExtJs 4.0.x
The new designer override functionality does not allow for the following properties:
extend - Is ignored
requires - Is ignored
mixins - Breaks
Error : me.mixins.observable is undefined
I am not sure what other properties are not catered for correctly but as it stands the overrides pattern is stunted and does not allow for a full replacement of the standard OO base-class => child class extension methodology.
With the current release I am seriously struggling to fit the designer into my development workflow and the number of work-arounds is becoming tedious.