# 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
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.
Returns True 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.
It is done 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):
"""Generic view to handle multiple DataTable classes in a single view.
Each DataTable class must be a :class:`~horizon.tables.DataTable` class
or its subclass.
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, {})
filters[filter_field] = filter_string
for k, v in filter_map.items():
# k is django.utils.functional.__proxy__
# and could not be searched in dict
if filter_string.lower() == k:
filters[filter_field] = v
break
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
class PagedTableMixin(object):
def __init__(self, *args, **kwargs):
super(PagedTableMixin, self).__init__(*args, **kwargs)
self._has_prev_data = False
self._has_more_data = False
def has_prev_data(self, table):
return self._has_prev_data
def has_more_data(self, table):
return self._has_more_data
def _get_marker(self):
try:
meta = self.table_class._meta
except AttributeError:
meta = self.table_classes[0]._meta
prev_marker = self.request.GET.get(meta.prev_pagination_param, None)
if prev_marker:
return prev_marker, "asc"
else:
marker = self.request.GET.get(meta.pagination_param, None)
if marker:
return marker, "desc"
return None, "desc"
