ModelAdmin code to make save_as work for models with unique slugs

save_as-with-unique-slugs

    def add_view(self, request, form_url='', extra_context=None):
        save_as_new = request.POST.get("_saveasnew", '')
        if extra_context is None:
            extra_context = {}
        # keep the save as new in case of validation errors
        extra_context['save_as_new'] = save_as_new
        # but if it is a real new addition, remove _saveasnew from POST
        if not save_as_new and '_saveasnew' in request.POST:
            del request.POST['_saveasnew']

        if save_as_new:
            request.POST['slug'] = self.make_slug_unique(request.POST['slug'])

        return super(RegistrationFormAdmin, self).add_view(request, form_url,
            extra_context=extra_context)


    def make_slug_unique(self, slug):
        counter = 1

        while True:
            not_unique = RegistrationForm.objects.filter(slug=slug)
            if len(not_unique) == 0:
                return slug
            slug = '{0}-{1}'.format(slug, counter)
            counter += 1