old_contents: # Copyright 2012 Nebula, Inc.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  from django.utils.translation import ugettext_lazy as _
  
  from horizon import exceptions
  from horizon import tabs
  
  from openstack_dashboard.api import cinder
  from openstack_dashboard.dashboards.project.snapshots import tables
  
  
  class OverviewTab(tabs.Tab):
      name = _("Overview")
      slug = "overview"
      template_name = ("project/volumes/_detail_overview.html")
  
      def get_context_data(self, request):
          return {"volume": self.tab_group.kwargs['volume']}
  
  
  class SnapshotTab(tabs.TableTab):
      table_classes = (tables.VolumeDetailsSnapshotsTable,)
      name = _("Snapshots")
      slug = "snapshots_tab"
      template_name = "horizon/common/_detail_table.html"
      preload = False
  
      def get_volume_snapshots_data(self):
          volume_id = self.tab_group.kwargs['volume_id']
          try:
              snapshots = cinder.volume_snapshot_list(
                  self.request, search_opts={'volume_id': volume_id})
              volume = cinder.volume_get(self.request, volume_id)
          except Exception:
              snapshots = []
              exceptions.handle(self.request,
                                _("Unable to retrieve volume snapshots for "
                                  "volume %s.") % volume_id)
  
          for snapshot in snapshots:
              snapshot._volume = volume
  
          return snapshots
  
  
  class VolumeDetailTabs(tabs.DetailTabsGroup):
      slug = "volume_details"
      tabs = (OverviewTab, SnapshotTab)
  
new_contents: # Copyright 2012 Nebula, Inc.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  from django.utils.translation import ugettext_lazy as _
  
  from horizon import exceptions
  from horizon import tabs
  
  from openstack_dashboard.api import cinder
  from openstack_dashboard.dashboards.project.snapshots import tables
  
  
  class OverviewTab(tabs.Tab):
      name = _("Overview")
      slug = "overview"
      template_name = ("project/volumes/_detail_overview.html")
  
      def get_context_data(self, request):
          return {"volume": self.tab_group.kwargs['volume']}
  
  
  class SnapshotTab(tabs.TableTab):
      table_classes = (tables.VolumeDetailsSnapshotsTable,)
      name = _("Snapshots")
      slug = "snapshots_tab"
      template_name = "horizon/common/_detail_table.html"
      preload = False
  
      def get_volume_snapshots_data(self):
          volume_id = self.tab_group.kwargs['volume_id']
          try:
              snapshots = cinder.volume_snapshot_list(
                  self.request, search_opts={'volume_id': volume_id})
          except Exception:
              snapshots = []
              exceptions.handle(self.request,
                                _("Unable to retrieve volume snapshots for "
                                  "volume %s.") % volume_id)
  
          try:
              volume = cinder.volume_get(self.request, volume_id)
          except Exception:
              volume = None
              exceptions.handle(self.request,
                                _("Unable to retrieve volume details for "
                                  "volume %s.") % volume_id)
  
          if volume is not None:
              for snapshot in snapshots:
                  snapshot._volume = volume
  
          return snapshots
  
  
  class VolumeDetailTabs(tabs.DetailTabsGroup):
      slug = "volume_details"
      tabs = (OverviewTab, SnapshotTab)
  
subject: Improve logic for volume snapshots tab