# 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 collections import defaultdict
from django import shortcuts
from horizon import views
from horizon.templatetags.horizon import has_permissions # noqa
class MultiTableMixin(object):
"""A generic mixin which provides methods for handling DataTables."""
data_method_pattern = "get_%s_data"
def __init__(self, *args, **kwargs):
super(MultiTableMixin, self).__init__(*args, **kwargs)
self.table_classes = getattr(self, "table_classes", [])
self._data = {}
self._tables = {}
self._data_methods = defaultdict(list)
self.get_data_methods(self.table_classes, self._data_methods)
def _get_data_dict(self):
if not self._data:
for table in self.table_classes:
data = []
name = table._meta.name
func_list = self._data_methods.get(name, [])
for func in func_list:
data.extend(func())
self._data[name] = data
return self._data
def get_data_methods(self, table_classes, methods):
for table in table_classes:
name = table._meta.name
if table._meta.mixed_data_type:
for data_type in table._meta.data_types:
func = self.check_method_exist(self.data_method_pattern,
data_type)
if func:
type_name = table._meta.data_type_name
methods[name].append(self.wrap_func(func,
type_name,
data_type))
else:
func = self.check_method_exist(self.data_method_pattern,
name)
if func:
methods[name].append(func)
def wrap_func(self, data_func, type_name, data_type):
def final_data():
data = data_func()
self.assign_type_string(data, type_name, data_type)
return data
return final_data
def check_method_exist(self, func_pattern="%s", *names):
func_name = func_pattern % names
func = getattr(self, func_name, None)
if not func or not callable(func):
cls_name = self.__class__.__name__
raise NotImplementedError("You must define a %s method "
"in %s." % (func_name, cls_name))
else:
return func
def assign_type_string(self, data, type_name, data_type):
for datum in data:
setattr(datum, type_name, data_type)
def get_tables(self):
if not self.table_classes:
raise AttributeError('You must specify one or more DataTable '
'classes for the "table_classes" attribute '
'on %s.' % self.__class__.__name__)
if not self._tables:
for table in self.table_classes:
if not has_permissions(self.request.user,
table._meta):
continue
func_name = "get_%s_table" % table._meta.name
table_func = getattr(self, func_name, None)
if table_func is None:
tbl = table(self.request, **self.kwargs)
else:
tbl = table_func(self, self.request, **self.kwargs)
self._tables[table._meta.name] = tbl
return self._tables
def get_context_data(self, **kwargs):
context = super(MultiTableMixin, self).get_context_data(**kwargs)
tables = self.get_tables()
for name, table in tables.items():
context["%s_table" % name] = table
return context
def has_prev_data(self, table):
return False
def has_more_data(self, table):
return False
def needs_filter_first(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].needs_filter_first = \
self.needs_filter_first(table)
self._tables[name]._meta.has_more_data = self.has_more_data(table)
self._tables[name]._meta.has_prev_data = self.has_prev_data(table)
handled = self._tables[name].maybe_handle()
return handled
def get_server_filter_info(self, request, table=None):
if not table:
table = self.get_table()
filter_action = table._meta._filter_action
if filter_action is None or filter_action.filter_type != 'server':
return None
param_name = filter_action.get_param_name()
filter_string = request.POST.get(param_name)
filter_string_session = request.session.get(param_name, "")
changed = (filter_string is not None
and filter_string != filter_string_session)
if filter_string is None:
filter_string = filter_string_session
filter_field_param = param_name + '_field'
filter_field = request.POST.get(filter_field_param)
filter_field_session = request.session.get(filter_field_param)
if filter_field is None and filter_field_session is not None:
filter_field = filter_field_session
filter_info = {
'action': filter_action,
'value_param': param_name,
'value': filter_string,
'field_param': filter_field_param,
'field': filter_field,
'changed': changed
}
return filter_info
def handle_server_filter(self, request, table=None):
"""Update the table server filter information in the session and
determine if the filter has been changed.
"""
if not table:
table = self.get_table()
filter_info = self.get_server_filter_info(request, table)
if filter_info is None:
return False
request.session[filter_info['value_param']] = filter_info['value']
if filter_info['field_param']:
request.session[filter_info['field_param']] = filter_info['field']
return filter_info['changed']
def update_server_filter_action(self, request, table=None):
"""Update the table server side filter action based on the current
filter. The filter info may be stored in the session and this will
restore it.
"""
if not table:
table = self.get_table()
filter_info = self.get_server_filter_info(request, table)
if filter_info is not None:
action = filter_info['action']
setattr(action, 'filter_string', filter_info['value'])
if filter_info['field_param']:
setattr(action, 'filter_field', filter_info['field'])
[docs]class MultiTableView(MultiTableMixin, views.HorizonTemplateView):
"""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
for table in tables:
preempted = table.maybe_preempt()
if preempted:
return preempted
# Load data into each table and check for action handlers
for table in tables:
handled = self.handle_table(table)
if handled:
return handled
# If we didn't already return a response, returning None continues
# with the view as normal.
return None
def get(self, request, *args, **kwargs):
handled = self.construct_tables()
if handled:
return handled
context = self.get_context_data(**kwargs)
return self.render_to_response(context)
def post(self, request, *args, **kwargs):
# GET and POST handling are the same
return self.get(request, *args, **kwargs)
[docs]class DataTableView(MultiTableView):
"""A class-based generic view to handle basic DataTable processing.
Three steps are required to use this view: set the ``table_class``
attribute with the desired :class:`~horizon.tables.DataTable` class;
define a ``get_data`` method which returns a set of data for the
table; and specify a template for the ``template_name`` attribute.
Optionally, you can override the ``has_more_data`` method to trigger
pagination handling for APIs that support it.
"""
table_class = None
context_object_name = 'table'
template_name = 'horizon/common/_data_table_view.html'
def _get_data_dict(self):
if not self._data:
self.update_server_filter_action(self.request)
self._data = {self.table_class._meta.name: self.get_data()}
return self._data
def get_data(self):
return []
def get_tables(self):
if not self._tables:
self._tables = {}
if has_permissions(self.request.user,
self.table_class._meta):
self._tables[self.table_class._meta.name] = self.get_table()
return self._tables
def get_table(self):
# Note: this method cannot be easily memoized, because get_context_data
# uses its cached value directly.
if not self.table_class:
raise AttributeError('You must specify a DataTable class for the '
'"table_class" attribute on %s.'
% self.__class__.__name__)
if not hasattr(self, "table"):
self.table = self.table_class(self.request, **self.kwargs)
return self.table
def get_context_data(self, **kwargs):
context = super(DataTableView, self).get_context_data(**kwargs)
if hasattr(self, "table"):
context[self.context_object_name] = self.table
return context
def post(self, request, *args, **kwargs):
# If the server side table filter changed then go back to the first
# page of data. Otherwise GET and POST handling are the same.
if self.handle_server_filter(request):
return shortcuts.redirect(self.get_table().get_absolute_url())
return self.get(request, *args, **kwargs)
def get_filters(self, filters=None, filters_map=None):
"""Converts a string given by the user into a valid api filter value.
:filters: Default filter values.
{'filter1': filter_value, 'filter2': filter_value}
:filters_map: mapping between user input and valid api filter values.
{'filter_name':{_("true_value"):True, _("false_value"):False}
"""
filters = filters or {}
filters_map = filters_map or {}
filter_action = self.table._meta._filter_action
if filter_action:
filter_field = self.table.get_filter_field()
if filter_action.is_api_filter(filter_field):
filter_string = self.table.get_filter_string().strip()
if filter_field and filter_string:
filter_map = filters_map.get(filter_field, {})
# We use the filter_string given by the user and
# look for valid values in the filter_map that's why
# we apply lower()
filters[filter_field] = filter_map.get(
filter_string.lower(), filter_string)
return filters
class MixedDataTableView(DataTableView):
"""A class-based generic view to handle DataTable with mixed data
types.
Basic usage is the same as DataTableView.
Three steps are required to use this view:
#. Set the ``table_class`` attribute with desired
:class:`~horizon.tables.DataTable` class. In the class the
``data_types`` list should have at least two elements.
#. Define a ``get_{{ data_type }}_data`` method for each data type
which returns a set of data for the table.
#. Specify a template for the ``template_name`` attribute.
"""
table_class = None
context_object_name = 'table'
def _get_data_dict(self):
if not self._data:
table = self.table_class
self._data = {table._meta.name: []}
for data_type in table.data_types:
func_name = "get_%s_data" % data_type
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 "
"for %s data type in %s." %
(func_name, data_type, cls_name))
data = data_func()
self.assign_type_string(data, data_type)
self._data[table._meta.name].extend(data)
return self._data
def assign_type_string(self, data, type_string):
for datum in data:
setattr(datum, self.table_class.data_type_name,
type_string)
def get_table(self):
self.table = super(MixedDataTableView, self).get_table()
if not self.table._meta.mixed_data_type:
raise AttributeError('You must have at least two elements in '
'the data_types attribute '
'in table %s to use MixedDataTableView.'
% self.table._meta.name)
return self.table