def get_context_data(self, **kwargs):
        kwargs = super(DiffView, self).get_context_data(**kwargs)
        try:
            before_url = self.request.GET['before']
            after_url = self.request.GET['after']
        except __HOLE__:
            raise Http404

        before = self.call_view_from_url(before_url)
        after = self.call_view_from_url(after_url)

        kwargs['diff'] = daisydiff(before, after)

        return kwargs
dataset/ETHPy150Open fusionbox/django-widgy/widgy/views/versioning.py/DiffView.get_context_data