Adds support for tabs + tables.

Creates new TableTab and TabbedTableView classes to support
the complex logic involved in processing both table and tab
actions in a single view.

Fixes bug 964214.

Change-Id: I3f70d77975593773bf783d31de06d2b724aad2d5

docs/source/ref/tabs.rst

@@ -27,6 +27,11 @@ view of data.
 .. autoclass:: Tab
     :members:
 
+.. autoclass:: TableTab
+    :members:
+
+
+
 TabView
 =======
 
@@ -35,3 +40,6 @@ the display of a :class:`~horizon.tabs.TabGroup` class.
 
 .. autoclass:: TabView
     :members:
+
+.. autoclass:: TabbedTableView
+    :members:

horizon/dashboards/nova/instances_and_volumes/instances/tables.py

@@ -175,8 +175,7 @@ class LogLink(tables.LinkAction):
 class UpdateRow(tables.Row):
     ajax = True
 
-    @classmethod
+    def get_data(self, request, instance_id):
-    def get_data(cls, request, instance_id):
         instance = api.server_get(request, instance_id)
         flavors = api.flavor_list(request)
         keyed_flavors = [(str(flavor.id), flavor) for flavor in flavors]

horizon/dashboards/nova/instances_and_volumes/volumes/tables.py

@@ -74,8 +74,7 @@ class CreateSnapshot(tables.LinkAction):
 class UpdateRow(tables.Row):
     ajax = True
 
-    @classmethod
+    def get_data(self, request, volume_id):
-    def get_data(cls, request, volume_id):
         volume = api.volume_get(request, volume_id)
         return volume
 

horizon/tables/__init__.py

@@ -18,4 +18,4 @@
 from .actions import (Action, BatchAction, DeleteAction,
                       LinkAction, FilterAction)
 from .base import DataTable, Column, Row
-from .views import DataTableView, MultiTableView
+from .views import DataTableView, MultiTableView, MultiTableMixin

horizon/tables/base.py

@@ -306,21 +306,36 @@ class Row(html.HTMLElement):
     ajax = False
     ajax_action_name = "row_update"
 
-    def __init__(self, table, datum):
+    def __init__(self, table, datum=None):
         super(Row, self).__init__()
         self.table = table
         self.datum = datum
-        id_vals = {"table": self.table.name,
+        if self.datum:
-                   "sep": STRING_SEPARATOR,
+            self.load_cells()
-                   "id": table.get_object_id(datum)}
+        else:
-        self.id = "%(table)s%(sep)srow%(sep)s%(id)s" % id_vals
+            self.id = None
-        if self.ajax:
+            self.cells = []
-            interval = settings.HORIZON_CONFIG.get('ajax_poll_interval', 2500)
-            self.attrs['data-update-interval'] = interval
-            self.attrs['data-update-url'] = self.get_ajax_update_url()
-            self.classes.append("ajax-update")
 
+    def load_cells(self, datum=None):
+        """
+        Load the row's data (either provided at initialization or as an
+        argument to this function), initiailize all the cells contained
+        by this row, and set the appropriate row properties which require
+        the row's data to be determined.
+
+        This function is called automatically by
+        :meth:`~horizon.tables.Row.__init__` if the ``datum`` argument is
+        provided. However, by not providing the data during initialization
+        this function allows for the possibility of a two-step loading
+        pattern when you need a row instance but don't yet have the data
+        available.
+        """
         # Compile all the cells on instantiation.
+        table = self.table
+        if datum:
+            self.datum = datum
+        else:
+            datum = self.datum
         cells = []
         for column in table.columns.values():
             if column.auto == "multi_select":
@@ -338,8 +353,18 @@ class Row(html.HTMLElement):
             cells.append((column.name or column.auto, cell))
         self.cells = SortedDict(cells)
 
+        if self.ajax:
+            interval = settings.HORIZON_CONFIG.get('ajax_poll_interval', 2500)
+            self.attrs['data-update-interval'] = interval
+            self.attrs['data-update-url'] = self.get_ajax_update_url()
+            self.classes.append("ajax-update")
+
         # Add the row's status class and id to the attributes to be rendered.
         self.classes.append(self.status_class)
+        id_vals = {"table": self.table.name,
+                   "sep": STRING_SEPARATOR,
+                   "id": table.get_object_id(datum)}
+        self.id = "%(table)s%(sep)srow%(sep)s%(id)s" % id_vals
         self.attrs['id'] = self.id
 
     def __repr__(self):
@@ -379,14 +404,13 @@ class Row(html.HTMLElement):
                             "obj_id": self.table.get_object_id(self.datum)})
         return "%s?%s" % (table_url, params)
 
-    @classmethod
+    def get_data(self, request, obj_id):
-    def get_data(cls, request, obj_id):
         """
         Fetches the updated data for the row based on the object id
         passed in. Must be implemented by a subclass to allow AJAX updating.
         """
         raise NotImplementedError("You must define a get_data method on %s"
-                                  % cls.__name__)
+                                  % self.__class__.__name__)
 
 
 class Cell(html.HTMLElement):
@@ -756,7 +780,7 @@ class DataTable(object):
 
         For convenience it defaults to the value of
         ``request.get_full_path()`` with any query string stripped off,
-         e.g. the path at which the table was requested.
+        e.g. the path at which the table was requested.
         """
         return self._meta.request.get_full_path().partition('?')[0]
 
@@ -833,7 +857,8 @@ class DataTable(object):
         context = template.RequestContext(self._meta.request, extra_context)
         return row_actions_template.render(context)
 
-    def parse_action(self, action_string):
+    @staticmethod
+    def parse_action(action_string):
         """
         Parses the ``action`` parameter (a string) sent back with the
         POST data. By default this parses a string formatted as
@@ -885,12 +910,11 @@ class DataTable(object):
                           _("Please select a row before taking that action."))
         return None
 
-    def _check_handler(self):
+    @classmethod
+    def check_handler(cls, request):
         """ Determine whether the request should be handled by this table. """
-        request = self._meta.request
-
         if request.method == "POST" and "action" in request.POST:
-            table, action, obj_id = self.parse_action(request.POST["action"])
+            table, action, obj_id = cls.parse_action(request.POST["action"])
         elif "table" in request.GET and "action" in request.GET:
             table = request.GET["table"]
             action = request.GET["action"]
@@ -904,22 +928,23 @@ class DataTable(object):
         Determine whether the request should be handled by a preemptive action
         on this table or by an AJAX row update before loading any data.
         """
-        table_name, action_name, obj_id = self._check_handler()
+        request = self._meta.request
+        table_name, action_name, obj_id = self.check_handler(request)
 
         if table_name == self.name:
             # Handle AJAX row updating.
-            row_class = self._meta.row_class
+            new_row = self._meta.row_class(self)
-            if row_class.ajax and row_class.ajax_action_name == action_name:
+            if new_row.ajax and new_row.ajax_action_name == action_name:
                 try:
-                    datum = row_class.get_data(self._meta.request, obj_id)
+                    datum = new_row.get_data(request, obj_id)
+                    new_row.load_cells(datum)
                     error = False
                 except:
                     datum = None
-                    error = exceptions.handle(self._meta.request, ignore=True)
+                    error = exceptions.handle(request, ignore=True)
-                if self._meta.request.is_ajax():
+                if request.is_ajax():
                     if not error:
-                        row = row_class(self, datum)
+                        return HttpResponse(new_row.render())
-                        return HttpResponse(row.render())
                     else:
                         return HttpResponse(status=error.status_code)
 
@@ -938,7 +963,8 @@ class DataTable(object):
         Determine whether the request should be handled by any action on this
         table after data has been loaded.
         """
-        table_name, action_name, obj_id = self._check_handler()
+        request = self._meta.request
+        table_name, action_name, obj_id = self.check_handler(request)
         if table_name == self.name and action_name:
             return self.take_action(action_name, obj_id)
         return None

horizon/tables/views.py

@@ -17,20 +17,10 @@
 from django.views import generic
 
 
-class MultiTableView(generic.TemplateView):
+class MultiTableMixin(object):
-    """
+    """ A generic mixin which provides methods for handling DataTables. """
-    A class-based generic view to handle the display and processing of
-    multiple :class:`~horizon.tables.DataTable` classes in a single view.
-
-    Three steps are required to use this view: set the ``table_classes``
-    attribute with a tuple of the desired
-    :class:`~horizon.tables.DataTable` classes;
-    define a ``get_{{ table_name }}_data`` method for each table class
-    which returns a set of data for that table; and specify a template for
-    the ``template_name`` attribute.
-    """
     def __init__(self, *args, **kwargs):
-        super(MultiTableView, self).__init__(*args, **kwargs)
+        super(MultiTableMixin, self).__init__(*args, **kwargs)
         self.table_classes = getattr(self, "table_classes", [])
         self._data = {}
         self._tables = {}
@@ -64,18 +54,36 @@ class MultiTableView(generic.TemplateView):
         return self._tables
 
     def get_context_data(self, **kwargs):
-        context = super(MultiTableView, self).get_context_data(**kwargs)
+        context = super(MultiTableMixin, self).get_context_data(**kwargs)
         tables = self.get_tables()
         for name, table in tables.items():
-            if table.data is None:
-                raise AttributeError('%s has no data associated with it.'
-                                     % table.__class__.__name__)
             context["%s_table" % name] = table
         return context
 
     def has_more_data(self, table):
         return False
 
+    def handle_table(self, table):
+        name = table.name
+        data = self._get_data_dict()
+        self._tables[name].data = data[table._meta.name]
+        self._tables[name]._meta.has_more_data = self.has_more_data(table)
+        handled = self._tables[name].maybe_handle()
+        return handled
+
+
+class MultiTableView(MultiTableMixin, generic.TemplateView):
+    """
+    A class-based generic view to handle the display and processing of
+    multiple :class:`~horizon.tables.DataTable` classes in a single view.
+
+    Three steps are required to use this view: set the ``table_classes``
+    attribute with a tuple of the desired
+    :class:`~horizon.tables.DataTable` classes;
+    define a ``get_{{ table_name }}_data`` method for each table class
+    which returns a set of data for that table; and specify a template for
+    the ``template_name`` attribute.
+    """
     def construct_tables(self):
         tables = self.get_tables().values()
         # Early out before data is loaded
@@ -84,14 +92,11 @@ class MultiTableView(generic.TemplateView):
             if preempted:
                 return preempted
         # Load data into each table and check for action handlers
-        data = self._get_data_dict()
         for table in tables:
-            name = table.name
+            handled = self.handle_table(table)
-            self._tables[name].data = data[table._meta.name]
-            self._tables[name]._meta.has_more_data = self.has_more_data(table)
-            handled = self._tables[name].maybe_handle()
             if handled:
                 return handled
+
         # If we didn't already return a response, returning None continues
         # with the view as normal.
         return None

horizon/tabs/__init__.py

@@ -14,5 +14,5 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from .base import TabGroup, Tab
+from .base import TabGroup, Tab, TableTab
-from .views import TabView
+from .views import TabView, TabbedTableView

horizon/tabs/base.py

@@ -95,14 +95,18 @@ class TabGroup(html.HTMLElement):
         self._tabs = SortedDict(tab_instances)
         if not self._set_active_tab():
             self.tabs_not_available()
-        # Preload all data that will be loaded to allow errors to be displayed
-        for tab in self._tabs.values():
-            if tab.load:
-                tab._context_data = tab.get_context_data(request)
 
     def __repr__(self):
         return "<%s: %s>" % (self.__class__.__name__, self.slug)
 
+    def load_tab_data(self):
+        """
+        Preload all data that for the tabs that will be displayed.
+        """
+        for tab in self._tabs.values():
+            if tab.load and not tab.data_loaded:
+                tab._data = tab.get_context_data(self.request)
+
     def get_id(self):
         """
         Returns the id for this tab group. Defaults to the value of the tab
@@ -171,6 +175,9 @@ class TabGroup(html.HTMLElement):
             return tab
         return None
 
+    def get_loaded_tabs(self):
+        return filter(lambda t: self.get_tab(t.slug), self._tabs.values())
+
     def get_selected_tab(self):
         """ Returns the tab specific by the GET request parameter.
 
@@ -254,15 +261,20 @@ class Tab(html.HTMLElement):
         return load_preloaded and self._allowed and self._enabled
 
     @property
-    def context_data(self):
+    def data(self):
-        if not getattr(self, "_context_data", None):
+        if not getattr(self, "_data", None):
-            self._context_data = self.get_context_data(self.request)
+            self._data = self.get_context_data(self.request)
-        return self._context_data
+        return self._data
+
+    @property
+    def data_loaded(self):
+        return getattr(self, "_data", None) is not None
 
     def render(self):
         """
-        Renders the tab to HTML using the :meth:`~horizon.tabs.Tab.get_data`
+        Renders the tab to HTML using the
-        method and the :meth:`~horizon.tabs.Tab.get_template_name` method.
+        :meth:`~horizon.tabs.Tab.get_context_data` method and
+        the :meth:`~horizon.tabs.Tab.get_template_name` method.
 
         If :attr:`~horizon.tabs.Tab.preload` is ``False`` and ``force_load``
         is not ``True``, or
@@ -273,7 +285,7 @@ class Tab(html.HTMLElement):
         if not self.load:
             return ''
         try:
-            context = self.context_data
+            context = self.data
         except exceptions.Http302:
             raise
         except:
@@ -350,3 +362,76 @@ class Tab(html.HTMLElement):
         The default behavior is to return ``True`` for all cases.
         """
         return True
+
+
+class TableTab(Tab):
+    """
+    A :class:`~horizon.tabs.Tab` class which knows how to deal with
+    :class:`~horizon.tables.DataTable` classes rendered inside of it.
+
+    This distinct class is required due to the complexity involved in handling
+    both dynamic tab loading, dynamic table updating and table actions all
+    within one view.
+
+    .. attribute:: table_classes
+
+        An iterable containing the :class:`~horizon.tables.DataTable` classes
+        which this tab will contain. Equivalent to the
+        :attr:`~horizon.tables.MultiTableView.table_classes` attribute on
+        :class:`~horizon.tables.MultiTableView`. For each table class you
+        need to define a corresponding ``get_{{ table_name }}_data`` method
+        as with :class:`~horizon.tables.MultiTableView`.
+    """
+    table_classes = None
+
+    def __init__(self, tab_group, request):
+        super(TableTab, self).__init__(tab_group, request)
+        if not self.table_classes:
+            class_name = self.__class__.__name__
+            raise NotImplementedError("You must define a table_class "
+                                      "attribute on %s" % class_name)
+        # Instantiate our table classes but don't assign data yet
+        table_instances = [(table._meta.name,
+                            table(request, **tab_group.kwargs))
+                           for table in self.table_classes]
+        self._tables = SortedDict(table_instances)
+        self._table_data_loaded = False
+
+    def load_table_data(self):
+        """
+        Calls the ``get_{{ table_name }}_data`` methods for each table class
+        and sets the data on the tables.
+        """
+        # We only want the data to be loaded once, so we track if we have...
+        if not self._table_data_loaded:
+            for table_name, table in self._tables.items():
+                # Fetch the data function.
+                func_name = "get_%s_data" % table_name
+                data_func = getattr(self, func_name, None)
+                if data_func is None:
+                    cls_name = self.__class__.__name__
+                    raise NotImplementedError("You must define a %s method "
+                                              "on %s." % (func_name, cls_name))
+                # Load the data.
+                table.data = data_func()
+            # Mark our data as loaded so we don't run the loaders again.
+            self._table_data_loaded = True
+
+    def get_context_data(self, request):
+        """
+        Adds a ``{{ table_name }}_table`` item to the context for each table
+        in the :attr:`~horizon.tabs.TableTab.table_classes` attribute.
+
+        If only one table class is provided, a shortcut ``table`` context
+        variable is also added containing the single table.
+        """
+        context = {}
+        # If the data hasn't been manually loaded before now,
+        # make certain it's loaded before setting the context.
+        self.load_table_data()
+        for table_name, table in self._tables.items():
+            # If there's only one table class, add a shortcut name as well.
+            if len(self.table_classes) == 1:
+                context["table"] = table
+            context["%s_table" % table_name] = table
+        return context

horizon/tabs/views.py

@@ -2,6 +2,8 @@ from django import http
 from django.views import generic
 
 from horizon import exceptions
+from horizon import tables
+from .base import TableTab
 
 
 class TabView(generic.TemplateView):
@@ -17,30 +19,45 @@ class TabView(generic.TemplateView):
         inherits from :class:`horizon.tabs.TabGroup`.
     """
     tab_group_class = None
+    _tab_group = None
 
     def __init__(self):
         if not self.tab_group_class:
             raise AttributeError("You must set the tab_group_class attribute "
                                  "on %s." % self.__class__.__name__)
 
-    def get_tabs(self, request, *args, **kwargs):
+    def get_tabs(self, request, **kwargs):
-        return self.tab_group_class(request, **kwargs)
+        """ Returns the initialized tab group for this view. """
+        if self._tab_group is None:
+            self._tab_group = self.tab_group_class(request, **kwargs)
+        return self._tab_group
 
-    def get(self, request, *args, **kwargs):
+    def get_context_data(self, **kwargs):
-        context = self.get_context_data(**kwargs)
+        """ Adds the ``tab_group`` variable to the context data. """
+        context = super(TabView, self).get_context_data(**kwargs)
         try:
-            tab_group = self.get_tabs(request, *args, **kwargs)
+            tab_group = self.get_tabs(self.request, **kwargs)
             context["tab_group"] = tab_group
         except:
-            exceptions.handle(request)
+            exceptions.handle(self.request)
+        return context
 
-        if request.is_ajax():
+    def handle_tabbed_response(self, tab_group, context):
+        """
+        Sends back an AJAX-appropriate response for the tab group if
+        required, otherwise renders the response as normal.
+        """
+        if self.request.is_ajax():
             if tab_group.selected:
                 return http.HttpResponse(tab_group.selected.render())
             else:
                 return http.HttpResponse(tab_group.render())
         return self.render_to_response(context)
 
+    def get(self, request, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+        return self.handle_tabbed_response(context["tab_group"], context)
+
     def render_to_response(self, *args, **kwargs):
         response = super(TabView, self).render_to_response(*args, **kwargs)
         # Because Django's TemplateView uses the TemplateResponse class
@@ -50,3 +67,79 @@ class TabView(generic.TemplateView):
         # of the exception-handling middleware.
         response.render()
         return response
+
+
+class TabbedTableView(tables.MultiTableMixin, TabView):
+    def __init__(self, *args, **kwargs):
+        super(TabbedTableView, self).__init__(*args, **kwargs)
+        self.table_classes = []
+        self._table_dict = {}
+
+    def load_tabs(self):
+        """
+        Loads the tab group, and compiles the table instances for each
+        table attached to any :class:`horizon.tabs.TableTab` instances on
+        the tab group. This step is necessary before processing any
+        tab or table actions.
+        """
+        tab_group = self.get_tabs(self.request, **self.kwargs)
+        tabs = tab_group.get_tabs()
+        for tab in [t for t in tabs if issubclass(t.__class__, TableTab)]:
+            self.table_classes.extend(tab.table_classes)
+            for table in tab._tables.values():
+                self._table_dict[table._meta.name] = {'table': table,
+                                                      'tab': tab}
+
+    def get_tables(self):
+        """ A no-op on this class. Tables are handled at the tab level. """
+        # Override the base class implementation so that the MultiTableMixin
+        # doesn't freak out. We do the processing at the TableTab level.
+        return {}
+
+    def handle_table(self, table_dict):
+        """
+        For the given dict containing a ``DataTable`` and a ``TableTab``
+        instance, it loads the table data for that tab and calls the
+        table's :meth:`~horizon.tables.DataTable.maybe_handle` method. The
+        return value will be the result of ``maybe_handle``.
+        """
+        table = table_dict['table']
+        tab = table_dict['tab']
+        tab.load_table_data()
+        table_name = table._meta.name
+        tab._tables[table_name]._meta.has_more_data = self.has_more_data(table)
+        handled = tab._tables[table_name].maybe_handle()
+        return handled
+
+    def get_context_data(self, **kwargs):
+        """ Adds the ``tab_group`` variable to the context data. """
+        context = super(TabbedTableView, self).get_context_data(**kwargs)
+        context['tab_group'].load_tab_data()
+        return context
+
+    def get(self, request, *args, **kwargs):
+        self.load_tabs()
+        # Gather our table instances. It's important that they're the
+        # actual instances and not the classes!
+        table_instances = [t['table'] for t in self._table_dict.values()]
+        # Early out before any tab or table data is loaded
+        for table in table_instances:
+            preempted = table.maybe_preempt()
+            if preempted:
+                return preempted
+
+        # If we have an action, determine if it belongs to one of our tables.
+        # We don't iterate through all of the tables' maybes_handle
+        # methods; just jump to the one that's got the matching name.
+        table_name, action, obj_id = tables.DataTable.check_handler(request)
+        if table_name in self._table_dict:
+            handled = self.handle_table(self._table_dict[table_name])
+            if handled:
+                return handled
+
+        context = self.get_context_data(**kwargs)
+        return self.handle_tabbed_response(context["tab_group"], context)
+
+    def post(self, request, *args, **kwargs):
+        # GET and POST handling are the same
+        return self.get(request, *args, **kwargs)

horizon/templates/horizon/common/_detail_table.html

@@ -0,0 +1 @@
+{{ table.render }}

horizon/tests/tabs_tests.py

@@ -20,6 +20,8 @@ from django.utils.translation import ugettext_lazy as _
 from horizon import tabs as horizon_tabs
 from horizon import test
 
+from .table_tests import MyTable, TEST_DATA
+
 
 class BaseTestTab(horizon_tabs.Tab):
     def get_context_data(self, request):
@@ -65,6 +67,26 @@ class Group(horizon_tabs.TabGroup):
         self._assert_tabs_not_available = True
 
 
+class TabWithTable(horizon_tabs.TableTab):
+    table_classes = (MyTable,)
+    name = _("Tab With My Table")
+    slug = "tab_with_table"
+    template_name = "horizon/common/_detail_table.html"
+
+    def get_my_table_data(self):
+        return TEST_DATA
+
+
+class TableTabGroup(horizon_tabs.TabGroup):
+    slug = "tab_group"
+    tabs = (TabWithTable,)
+
+
+class TabWithTableView(horizon_tabs.TabbedTableView):
+    tab_group_class = TableTabGroup
+    template_name = "tab_group.html"
+
+
 class TabTests(test.TestCase):
     def setUp(self):
         super(TabTests, self).setUp()
@@ -190,3 +212,56 @@ class TabTests(test.TestCase):
         tab_delayed = tg.get_tab("tab_delayed")
         output = tab_delayed.render()
         self.assertEqual(output.strip(), tab_delayed.name)
+
+    def test_table_tabs(self):
+        tab_group = TableTabGroup(self.request)
+        tabs = tab_group.get_tabs()
+        # Only one tab, as expected.
+        self.assertEqual(len(tabs), 1)
+        tab = tabs[0]
+        # Make sure it's the tab we think it is.
+        self.assertTrue(isinstance(tab, horizon_tabs.TableTab))
+        # Data should not be loaded yet.
+        self.assertFalse(tab._table_data_loaded)
+        table = tab._tables[MyTable.Meta.name]
+        self.assertTrue(isinstance(table, MyTable))
+        # Let's make sure the data *really* isn't loaded yet.
+        self.assertEqual(table.data, None)
+        # Okay, load the data.
+        tab.load_table_data()
+        self.assertTrue(tab._table_data_loaded)
+        self.assertQuerysetEqual(table.data, ['<FakeObject: object_1>',
+                                              '<FakeObject: object_2>',
+                                              '<FakeObject: object_3>'])
+        context = tab.get_context_data(self.request)
+        # Make sure our table is loaded into the context correctly
+        self.assertEqual(context['my_table_table'], table)
+        # Since we only had one table we should get the shortcut name too.
+        self.assertEqual(context['table'], table)
+
+    def test_tabbed_table_view(self):
+        view = TabWithTableView.as_view()
+
+        # Be sure we get back a rendered table containing data for a GET
+        req = self.factory.get("/")
+        res = view(req)
+        self.assertContains(res, "<table", 1)
+        self.assertContains(res, "Displaying 3 items", 1)
+
+        # AJAX response to GET for row update
+        params = {"table": "my_table", "action": "row_update", "obj_id": "1"}
+        req = self.factory.get('/', params,
+                               HTTP_X_REQUESTED_WITH='XMLHttpRequest')
+        res = view(req)
+        self.assertEqual(res.status_code, 200)
+        # Make sure we got back a row but not a table or body
+        self.assertContains(res, "<tr", 1)
+        self.assertContains(res, "<table", 0)
+        self.assertContains(res, "<body", 0)
+
+        # Response to POST for table action
+        action_string = "my_table__toggle__2"
+        req = self.factory.post('/', {'action': action_string})
+        res = view(req)
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res["location"], "/")

horizon/tests/templates/tab_group.html

@@ -0,0 +1 @@
+{{ tab_group.render }}