Separate "modal" behavior from "self-handling" in forms.

Splits behaviors related to a form being modal from the
requirement that the form also be self-handling by making
the component classes into mixins. This allows mixing
modal capabilities into other generic form classes.

Change-Id: Id9fb7d278e7cb48d923e2a0dd5cc6dd524a7b073

horizon/forms/__init__.py

@@ -20,6 +20,6 @@ from django.forms import *
 from django.forms import widgets
 
 # Convenience imports for public API components.
-from .base import SelfHandlingForm, DateForm
-from .views import ModalFormView
+from .base import SelfHandlingMixin, SelfHandlingForm, DateForm
+from .views import ModalFormView, ModalFormMixin
 from .fields import DynamicTypedChoiceField, DynamicChoiceField

horizon/forms/base.py

@@ -23,19 +23,20 @@ from django.forms.forms import NON_FIELD_ERRORS
 from django.utils import dates, timezone
 
 
-class SelfHandlingForm(forms.Form):
-    """
-    A base :class:`Form <django:django.forms.Form>` class which includes
-    processing logic in its subclasses.
-    """
-
+class SelfHandlingMixin(object):
     def __init__(self, request, *args, **kwargs):
         self.request = request
         if not hasattr(self, "handle"):
             raise NotImplementedError("%s does not define a handle method."
                                       % self.__class__.__name__)
-        super(SelfHandlingForm, self).__init__(*args, **kwargs)
+        super(SelfHandlingMixin, self).__init__(*args, **kwargs)
 
+
+class SelfHandlingForm(SelfHandlingMixin, forms.Form):
+    """
+    A base :class:`Form <django:django.forms.Form>` class which includes
+    processing logic in its subclasses.
+    """
     def api_error(self, message):
         """
         Adds an error to the form's error dictionary after validation

horizon/forms/views.py

@@ -23,7 +23,7 @@ from horizon.openstack.common import jsonutils
 from horizon import exceptions
 
 
-class ModalFormView(generic.FormView):
+class ModalFormMixin(object):
     def get_template_names(self):
         if self.request.is_ajax():
             if not hasattr(self, "ajax_template_name"):
@@ -36,18 +36,20 @@ class ModalFormView(generic.FormView):
             template = self.template_name
         return template
 
+    def get_context_data(self, **kwargs):
+        context = super(ModalFormMixin, self).get_context_data(**kwargs)
+        if self.request.is_ajax():
+            context['hide'] = True
+        return context
+
+
+class ModalFormView(ModalFormMixin, generic.FormView):
     def get_object_id(self, obj):
         return obj.id
 
     def get_object_display(self, obj):
         return obj.name
 
-    def get_context_data(self, **kwargs):
-        context = super(ModalFormView, self).get_context_data(**kwargs)
-        if self.request.is_ajax():
-            context['hide'] = True
-        return context
-
     def get_form(self, form_class):
         """
         Returns an instance of the form to be used in this view.