Add CBV to display a list of object that are the children of another object

mayan/apps/common/views.py

@@ -7,7 +7,7 @@ from django.contrib import messages
 from django.contrib.auth.models import User
 from django.contrib.auth.views import login, password_change
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import PermissionDenied
+from django.core.exceptions import ImproperlyConfigured, PermissionDenied
 from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
 from django.shortcuts import redirect, render_to_response
@@ -15,6 +15,7 @@ from django.template import RequestContext
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic import FormView, TemplateView
+from django.views.generic.detail import SingleObjectMixin
 from django.views.generic.edit import CreateView, DeleteView, UpdateView
 from django.views.generic.list import ListView
 
@@ -32,6 +33,7 @@ from .mixins import (
     ExtraContextMixin, ObjectListPermissionFilterMixin,
     ObjectPermissionCheckMixin, RedirectionMixin, ViewPermissionCheckMixin
 )
+from .utils import return_attrib
 
 
 class AssignRemoveView(TemplateView):
@@ -370,6 +372,84 @@ class SingleObjectListView(ViewPermissionCheckMixin, ObjectListPermissionFilterM
     template_name = 'appearance/generic_list.html'
 
 
+class ParentChildListView(ViewPermissionCheckMixin, ObjectPermissionCheckMixin, ExtraContextMixin, ListView, SingleObjectMixin):
+    parent_model = None
+    parent_queryset = None
+    template_name = 'appearance/generic_list.html'
+
+    def get(self, request, *args, **kwargs):
+        # Parent
+        self.object = self.get_object()
+
+        # Children
+        self.object_list = self.get_queryset()
+        allow_empty = self.get_allow_empty()
+        if not allow_empty:
+            # When pagination is enabled and object_list is a queryset,
+            # it's better to do a cheap query than to load the unpaginated
+            # queryset in memory.
+            if (self.get_paginate_by(self.object_list) is not None
+                    and hasattr(self.object_list, 'exists')):
+                is_empty = not self.object_list.exists()
+            else:
+                is_empty = len(self.object_list) == 0
+            if is_empty:
+                raise Http404(_("Empty list and '%(class_name)s.allow_empty' is False.")
+                        % {'class_name': self.__class__.__name__})
+
+        context = self.get_context_data(object=self.object)
+        return self.render_to_response(context)
+
+    def get_object(self, queryset=None):
+        # Use a custom queryset if provided; this is required for subclasses
+        # like DateDetailView
+        if queryset is None:
+            queryset = self.get_parent_queryset()
+        # Next, try looking up by primary key.
+        pk = self.kwargs.get(self.pk_url_kwarg, None)
+        slug = self.kwargs.get(self.slug_url_kwarg, None)
+        if pk is not None:
+            queryset = queryset.filter(pk=pk)
+        # Next, try looking up by slug.
+        if slug is not None and (pk is None or self.query_pk_and_slug):
+            slug_field = self.get_slug_field()
+            queryset = queryset.filter(**{slug_field: slug})
+        # If none of those are defined, it's an error.
+        if pk is None and slug is None:
+            raise AttributeError("Generic detail view %s must be called with "
+                                 "either an object pk or a slug."
+                                 % self.__class__.__name__)
+        try:
+            # Get the single item from the filtered queryset
+            obj = queryset.get()
+        except queryset.model.DoesNotExist:
+            raise Http404(_("No %(verbose_name)s found matching the query") %
+                          {'verbose_name': queryset.model._meta.verbose_name})
+        return obj
+
+    def get_parent_queryset(self):
+        """
+        Return the `QuerySet` that will be used to look up the object.
+        Note that this method is called by the default implementation of
+        `get_object` and may not be called if `get_object` is overridden.
+        """
+        if self.parent_queryset is None:
+            if self.parent_model:
+                return self.model._default_manager.all()
+            else:
+                raise ImproperlyConfigured(
+                    "%(cls)s is missing a QuerySet. Define "
+                    "%(cls)s.parent_model, %(cls)s.parent_queryset, or override "
+                    "%(cls)s.get_parent_queryset()." % {
+                        'cls': self.__class__.__name__
+                    }
+                )
+        return self.parent_queryset.all()
+
+    def get_queryset(self):
+        raise NotImplementedError
+
+
 class SetupListView(TemplateView):
     template_name = 'appearance/generic_list_horizontal.html'