Handle "null" time values for Stacks

The timesince filter expects a date or datetime object, and would fail
when receiving an empty string. Create a new filter that returns the
string value "Never" under these circumstances.

Change-Id: I73f4dbb608fc143c3ac60d753e9e222762579e51
Closes-Bug: #1286959

horizon/test/tests/utils.py

@@ -15,11 +15,11 @@
 #    under the License.
 
 import datetime
-
 import os
 
 from django.core.exceptions import ValidationError  # noqa
 import django.template
+from django.template import defaultfilters
 
 from horizon.test import helpers as test
 from horizon.utils import fields
@@ -288,6 +288,50 @@ class FiltersTests(test.TestCase):
         self.assertIsInstance(result, datetime.datetime)
 
 
+class TimeSinceNeverFilterTests(test.TestCase):
+
+    default = u"Never"
+
+    def test_timesince_or_never_returns_default_for_empty_string(self):
+        c = django.template.Context({'time': ''})
+        t = django.template.Template('{{time|timesince_or_never}}')
+        self.assertEqual(t.render(c), self.default)
+
+    def test_timesince_or_never_returns_default_for_none(self):
+        c = django.template.Context({'time': None})
+        t = django.template.Template('{{time|timesince_or_never}}')
+        self.assertEqual(t.render(c), self.default)
+
+    def test_timesince_or_never_returns_default_for_gibberish(self):
+        c = django.template.Context({'time': django.template.Context()})
+        t = django.template.Template('{{time|timesince_or_never}}')
+        self.assertEqual(t.render(c), self.default)
+
+    def test_timesince_or_never_returns_with_custom_default(self):
+        custom = "Hello world"
+        c = django.template.Context({'date': ''})
+        t = django.template.Template('{{date|timesince_or_never:"%s"}}'
+                                     % custom)
+        self.assertEqual(t.render(c), custom)
+
+    def test_timesince_or_never_returns_with_custom_empty_string_default(self):
+        c = django.template.Context({'date': ''})
+        t = django.template.Template('{{date|timesince_or_never:""}}')
+        self.assertEqual(t.render(c), "")
+
+    def test_timesince_or_never_returns_same_output_as_django_date(self):
+        d = datetime.date(year=2014, month=3, day=7)
+        c = django.template.Context({'date': d})
+        t = django.template.Template('{{date|timesince_or_never}}')
+        self.assertEqual(t.render(c), defaultfilters.timesince(d))
+
+    def test_timesince_or_never_returns_same_output_as_django_datetime(self):
+        now = datetime.datetime.now()
+        c = django.template.Context({'date': now})
+        t = django.template.Template('{{date|timesince_or_never}}')
+        self.assertEqual(t.render(c), defaultfilters.timesince(now))
+
+
 class MemoizedTests(test.TestCase):
     def test_memoized_decorator_cache_on_next_call(self):
         values_list = []

horizon/utils/filters.py

@@ -14,12 +14,15 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import datetime
+
 import iso8601
 
 from django.template.defaultfilters import register  # noqa
 from django.template.defaultfilters import timesince  # noqa
 from django.utils.safestring import mark_safe
 from django.utils import timezone
+from django.utils.translation import ugettext_lazy as _
 
 
 @register.filter
@@ -38,6 +41,21 @@ def parse_isotime(timestr, default=None):
         return default or ''
 
 
+@register.filter
+def timesince_or_never(dt, default=None):
+    """Call the Django ``timesince`` filter, but return the string
+    *default* if *dt* is not a valid ``date`` or ``datetime`` object.
+    When *default* is None, "Never" is returned.
+    """
+    if default is None:
+        default = _("Never")
+
+    if isinstance(dt, datetime.date):
+        return timesince(dt)
+    else:
+        return default
+
+
 @register.filter
 def timesince_sortable(dt):
     delta = timezone.now() - dt

openstack_dashboard/dashboards/project/stacks/tables.py

@@ -14,7 +14,6 @@
 
 from django.core import urlresolvers
 from django.http import Http404  # noqa
-from django.template.defaultfilters import timesince  # noqa
 from django.template.defaultfilters import title  # noqa
 from django.utils.http import urlencode  # noqa
 from django.utils.translation import ugettext_lazy as _
@@ -90,10 +89,12 @@ class StacksTable(tables.DataTable):
                          link="horizon:project:stacks:detail",)
     created = tables.Column("creation_time",
                             verbose_name=_("Created"),
-                            filters=(filters.parse_isotime, timesince))
+                            filters=(filters.parse_isotime,
+                                     filters.timesince_or_never))
     updated = tables.Column("updated_time",
                             verbose_name=_("Updated"),
-                            filters=(filters.parse_isotime, timesince))
+                            filters=(filters.parse_isotime,
+                                     filters.timesince_or_never))
     status = tables.Column("status",
                            filters=(title, filters.replace_underscores),
                            verbose_name=_("Status"),
@@ -123,7 +124,8 @@ class EventsTable(tables.DataTable):
                                       link=mappings.resource_to_url)
     timestamp = tables.Column('event_time',
                               verbose_name=_("Time Since Event"),
-                              filters=(filters.parse_isotime, timesince))
+                              filters=(filters.parse_isotime,
+                                       filters.timesince_or_never))
     status = tables.Column("resource_status",
                            filters=(title, filters.replace_underscores),
                            verbose_name=_("Status"),)
@@ -169,7 +171,8 @@ class ResourcesTable(tables.DataTable):
                            verbose_name=_("Stack Resource Type"),)
     updated_time = tables.Column('updated_time',
                               verbose_name=_("Date Updated"),
-                              filters=(filters.parse_isotime, timesince))
+                              filters=(filters.parse_isotime,
+                                       filters.timesince_or_never))
     status = tables.Column("resource_status",
                            filters=(title, filters.replace_underscores),
                            verbose_name=_("Status"),

openstack_dashboard/dashboards/project/stacks/templates/stacks/_detail_overview.html

@@ -20,9 +20,9 @@
   <hr class="header_rule">
   <dl>
     <dt>{% trans "Created" %}</dt>
-    <dd>{{ stack.creation_time|parse_isotime|timesince }}</dd>
+    <dd>{{ stack.creation_time|parse_isotime|timesince_or_never }}</dd>
     <dt>{% trans "Last Updated" %}</dt>
-    <dd>{{ stack.updated_time|parse_isotime|timesince }}</dd>
+    <dd>{{ stack.updated_time|parse_isotime|timesince_or_never }}</dd>
     <dt>{% trans "Status" %}</dt>
     <dd>{{ stack.stack_status|title }}: {{ stack.stack_status_reason }}</dd>
   </dl>

openstack_dashboard/dashboards/project/stacks/templates/stacks/_resource_overview.html

@@ -32,7 +32,7 @@
   <hr class="header_rule">
   <dl>
     <dt>{% trans "Last Updated" %}</dt>
-    <dd>{{ resource.updated_time|parse_isotime|timesince }}</dd>
+    <dd>{{ resource.updated_time|parse_isotime|timesince_or_never }}</dd>
     <dt>{% trans "Status" %}</dt>
     <dd>{{ resource.resource_status|title|replace_underscores }}: {{ resource.resource_status_reason }}</dd>
   </dl>

openstack_dashboard/test/test_data/heat_data.py

@@ -353,7 +353,7 @@ def data(TEST):
         "stack_status_reason": "Stack successfully created",
         "stack_name": "stack-test",
         "creation_time": "2013-04-22T00:11:39Z",
-        "updated_time": "2013-04-22T00:11:39Z",
+        "updated_time": "null",
         "stack_status": "CREATE_COMPLETE",
         "id": "05b4f39f-ea96-4d91-910c-e758c078a089"
     }