base: add mixins for child model views (#32652)

passerelle/base/mixins.py

@@ -0,0 +1,47 @@
+# passerelle - uniform access to multiple data sources and services
+# Copyright (C) 2019 Entr'ouvert
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from django.utils import functional
+
+
+class ResourceChildViewMixin(object):
+    '''Mixin to help implementing view for child objects of resource objets.'''
+
+    @property
+    def resource_class(self):
+        field = self.model._meta.get_field('resource')
+        return field.related_model
+
+    @property
+    def model_verbose_name(self):
+        return self.model._meta.verbose_name
+
+    @property
+    def model_verbose_name_plural(self):
+        return self.model._meta.verbose_name_plural
+
+    @functional.cached_property
+    def resource(self):
+        return self.resource_class.objects.get(slug=self.kwargs['slug'])
+
+    def get_queryset(self):
+        qs = super(ResourceChildViewMixin, self).get_queryset()
+        return qs.filter(resource=self.resource)
+
+    def get_success_url(self):
+        return self.resource.get_absolute_url()
+
+