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  # Copyright 2012 NEC Corporation
  #
  #    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.
  
  import logging
  
  from django.core.urlresolvers import reverse
  from django.core.urlresolvers import reverse_lazy
  from django.utils.translation import ugettext_lazy as _
  
  from horizon import exceptions
  from horizon import tables
  from horizon.utils import memoized
  
  from openstack_dashboard import api
  
  
  LOG = logging.getLogger(__name__)
  
  
  class CheckNetworkEditable(object):
      """Mixin class to determine the specified network is editable."""
  
      def allowed(self, request, datum=None):
          # Only administrator is allowed to create and manage subnets
          # on shared networks.
          network = self.table._get_network()
          if network.shared:
              return False
          return True
  
  
  class DeleteSubnet(CheckNetworkEditable, tables.DeleteAction):
      data_type_singular = _("Subnet")
      data_type_plural = _("Subnets")
  
      def delete(self, request, obj_id):
          try:
              api.neutron.subnet_delete(request, obj_id)
          except Exception:
              msg = _('Failed to delete subnet %s') % obj_id
              LOG.info(msg)
              network_id = self.table.kwargs['network_id']
              redirect = reverse('horizon:project:networks:detail',
                                 args=[network_id])
              exceptions.handle(request, msg, redirect=redirect)
  
  
  class CreateSubnet(CheckNetworkEditable, tables.LinkAction):
      name = "create"
      verbose_name = _("Create Subnet")
      url = "horizon:project:networks:addsubnet"
      classes = ("ajax-modal", "btn-create")
  
      def get_link_url(self, datum=None):
          network_id = self.table.kwargs['network_id']
          return reverse(self.url, args=(network_id,))
  
  
  class UpdateSubnet(CheckNetworkEditable, tables.LinkAction):
      name = "update"
      verbose_name = _("Edit Subnet")
      url = "horizon:project:networks:editsubnet"
      classes = ("ajax-modal", "btn-edit")
  
      def get_link_url(self, subnet):
          network_id = self.table.kwargs['network_id']
          return reverse(self.url, args=(network_id, subnet.id))
  
  
  class SubnetsTable(tables.DataTable):
      name = tables.Column("name", verbose_name=_("Name"),
                           link='horizon:project:networks:subnets:detail')
      cidr = tables.Column("cidr", verbose_name=_("Network Address"))
      ip_version = tables.Column("ipver_str", verbose_name=_("IP Version"))
      gateway_ip = tables.Column("gateway_ip", verbose_name=_("Gateway IP"))
      failure_url = reverse_lazy('horizon:project:networks:index')
  
      @memoized.memoized_method
      def _get_network(self):
          try:
              network_id = self.kwargs['network_id']
              network = api.neutron.network_get(self.request, network_id)
              network.set_id_as_name_if_empty(length=0)
          except Exception:
              msg = _('Unable to retrieve details for network "%s".') \
                  % (network_id)
              exceptions.handle(self.request, msg, redirect=self.failure_url)
          return network
  
      class Meta:
          name = "subnets"
          verbose_name = _("Subnets")
          table_actions = (CreateSubnet, DeleteSubnet)
          row_actions = (UpdateSubnet, DeleteSubnet)
  