Running logic on update in tastypie

gistfile1.py

from tastypie.resources import ModelResource

class FlaggedResource(ModelResource):
    def obj_update(self, bundle, request=None, **kwargs):
        processFlag = bundle.obj and not bundle.obj.flagged
        bundle = super(FlaggedResource, self).obj_update(bundle, request, **kwargs)
        if processFlag:
            bundle.obj.flagLogic()
        return bundle