Add polymorphic.contrib.extra_views to combine polymorphic with django-extra-views

polymorphic/contrib/extra_views.py

@@ -0,0 +1,126 @@
+"""
+The ``extra_views.formsets`` provides a simple way to handle formsets.
+The ``extra_views.advanced`` provides a method to combine that with a create/update form.
+
+This package provides classes that support both options for polymorphic formsets.
+"""
+from __future__ import absolute_import
+from django.core.exceptions import ImproperlyConfigured
+import extra_views
+from polymorphic.formsets import polymorphic_child_forms_factory, BasePolymorphicModelFormSet, BasePolymorphicInlineFormSet
+
+
+__all__ = (
+    'PolymorphicFormSetView',
+    'PolymorphicInlineFormSetView',
+    'PolymorphicInlineFormSet',
+)
+
+
+class PolymorphicFormSetMixin(object):
+    """
+    Internal Mixin, that provides polymorphic integration with the ``extra_views`` package.
+    """
+
+    formset_class = BasePolymorphicModelFormSet
+
+    #: Default 0 extra forms
+    extra = 0
+
+    #: Define the children
+    # :type: list[PolymorphicFormSetChild]
+    formset_children = None
+
+    def get_formset_children(self):
+        """
+        :rtype: list[PolymorphicFormSetChild]
+        """
+        if not self.formset_children:
+            raise ImproperlyConfigured("Define 'formset_children' as list of `PolymorphicFormSetChild`")
+        return self.formset_children
+
+    def get_formset_child_kwargs(self):
+        return {}
+
+    def get_formset(self):
+        """
+        Returns the formset class from the inline formset factory
+        """
+        # Implementation detail:
+        # Since `polymorphic_modelformset_factory` and `polymorphic_inlineformset_factory` mainly
+        # reuse the standard factories, and then add `child_forms`, the same can be done here.
+        # This makes sure the base class construction is completely honored.
+        FormSet = super(PolymorphicFormSetMixin, self).get_formset()
+        FormSet.child_forms = polymorphic_child_forms_factory(self.get_formset_children(), **self.get_formset_child_kwargs())
+        return FormSet
+
+
+class PolymorphicFormSetView(PolymorphicFormSetMixin, extra_views.ModelFormSetView):
+    """
+    A view that displays a single polymorphic formset.
+
+    .. code-block:: python
+
+        from polymorphic.formsets import PolymorphicFormSetChild
+
+
+        class ItemsView(PolymorphicFormSetView):
+            model = Item
+            formset_children = [
+                PolymorphicFormSetChild(ItemSubclass1),
+                PolymorphicFormSetChild(ItemSubclass2),
+            ]
+
+    """
+    formset_class = BasePolymorphicModelFormSet
+
+
+class PolymorphicInlineFormSetView(PolymorphicFormSetMixin, extra_views.InlineFormSetView):
+    """
+    A view that displays a single polymorphic formset - with one parent object.
+    This is a variation of the :mod:`extra_views` package classes for django-polymorphic.
+
+    .. code-block:: python
+
+        from polymorphic.formsets import PolymorphicFormSetChild
+
+
+        class OrderItemsView(PolymorphicInlineFormSetView):
+            model = Order
+            inline_model = Item
+            formset_children = [
+                PolymorphicFormSetChild(ItemSubclass1),
+                PolymorphicFormSetChild(ItemSubclass2),
+            ]
+    """
+    formset_class = BasePolymorphicInlineFormSet
+
+
+class PolymorphicInlineFormSet(PolymorphicFormSetMixin, extra_views.InlineFormSet):
+    """
+    An inline to add to the ``inlines`` of
+    the :class:`~extra_views.advanced.CreateWithInlinesView`
+    and :class:`~extra_views.advanced.UpdateWithInlinesView` class.
+
+    .. code-block:: python
+
+        from polymorphic.formsets import PolymorphicFormSetChild
+
+
+        class ItemsInline(PolymorphicInlineFormSet):
+            model = Item
+            formset_children = [
+                PolymorphicFormSetChild(ItemSubclass1),
+                PolymorphicFormSetChild(ItemSubclass2),
+            ]
+
+
+        class OrderCreateView(CreateWithInlinesView):
+            model = Order
+            inlines = [ItemsInline]
+
+            def get_success_url(self):
+                return self.object.get_absolute_url()
+
+    """
+    formset_class = BasePolymorphicInlineFormSet