# 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 OrderedDict
import sys
import six
from django.template.loader import render_to_string
from django.template import TemplateSyntaxError # noqa
from horizon import exceptions
from horizon.utils import html
SEPARATOR = "__"
CSS_TAB_GROUP_CLASSES = ["nav", "nav-tabs", "ajax-tabs"]
CSS_ACTIVE_TAB_CLASSES = ["active"]
CSS_DISABLED_TAB_CLASSES = ["disabled"]
[docs]class TabGroup(html.HTMLElement):
"""A container class which knows how to manage and render
:class:`~horizon.tabs.Tab` objects.
.. attribute:: slug
The URL slug and pseudo-unique identifier for this tab group.
.. attribute:: template_name
The name of the template which will be used to render this tab group.
Default: ``"horizon/common/_tab_group.html"``
.. attribute:: sticky
Boolean to control whether the active tab state should be stored
across requests for a given user. (State storage is all done
client-side.)
.. attribute:: show_single_tab
Boolean to control whether the tab bar is shown when the tab group
has only one tab. Default: ``False``
.. attribute:: param_name
The name of the GET request parameter which will be used when
requesting specific tab data. Default: ``tab``.
.. attribute:: classes
A list of CSS classes which should be displayed on this tab group.
.. attribute:: attrs
A dictionary of HTML attributes which should be rendered into the
markup for this tab group.
.. attribute:: selected
Read-only property which is set to the instance of the
currently-selected tab if there is one, otherwise ``None``.
.. attribute:: active
Read-only property which is set to the value of the current active tab.
This may not be the same as the value of ``selected`` if no
specific tab was requested via the ``GET`` parameter.
"""
slug = None
template_name = "horizon/common/_tab_group.html"
param_name = 'tab'
sticky = False
show_single_tab = False
_selected = None
_active = None
@property
[docs] def selected(self):
return self._selected
@property
[docs] def active(self):
return self._active
def __init__(self, request, **kwargs):
super(TabGroup, self).__init__()
if not hasattr(self, "tabs"):
raise NotImplementedError('%s must declare a "tabs" attribute.'
% self.__class__)
if not self.slug:
raise NotImplementedError('%s must declare a "slug" attribute.'
% self.__class__)
self.request = request
self.kwargs = kwargs
self._data = None
tab_instances = []
for tab in self.tabs:
tab_instances.append((tab.slug, tab(self, request)))
self._tabs = OrderedDict(tab_instances)
if self.sticky:
self.attrs['data-sticky-tabs'] = 'sticky'
if not self._set_active_tab():
self.tabs_not_available()
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.slug)
[docs] def load_tab_data(self):
"""Preload all data that for the tabs that will be displayed."""
for tab in self._tabs.values():
if tab.load and not tab.data_loaded:
try:
tab._data = tab.get_context_data(self.request)
except Exception:
tab._data = False
exceptions.handle(self.request)
[docs] def get_id(self):
"""Returns the id for this tab group. Defaults to the value of the tab
group's :attr:`horizon.tabs.Tab.slug`.
"""
return self.slug
[docs] def get_default_classes(self):
"""Returns a list of the default classes for the tab group. Defaults to
``["nav", "nav-tabs", "ajax-tabs"]``.
"""
default_classes = super(TabGroup, self).get_default_classes()
default_classes.extend(CSS_TAB_GROUP_CLASSES)
return default_classes
[docs] def tabs_not_available(self):
"""In the event that no tabs are either allowed or enabled, this method
is the fallback handler. By default it's a no-op, but it exists
to make redirecting or raising exceptions possible for subclasses.
"""
pass
def _set_active_tab(self):
marked_active = None
# See if we have a selected tab via the GET parameter.
tab = self.get_selected_tab()
if tab:
tab._active = True
self._active = tab
marked_active = tab
# Iterate through to mark them all accordingly.
for tab in self._tabs.values():
if tab._allowed and tab._enabled and not marked_active:
tab._active = True
self._active = tab
marked_active = True
elif tab == marked_active:
continue
else:
tab._active = False
return marked_active
[docs] def render(self):
"""Renders the HTML output for this tab group."""
return render_to_string(self.template_name, {"tab_group": self})
[docs] def get_tabs(self):
"""Returns a list of the allowed tabs for this tab group."""
return [tab for tab in self._tabs.values() if tab._allowed]
[docs] def get_tab(self, tab_name, allow_disabled=False):
"""Returns a specific tab from this tab group.
If the tab is not allowed or not enabled this method returns ``None``.
If the tab is disabled but you wish to return it anyway, you can pass
``True`` to the allow_disabled argument.
"""
tab = self._tabs.get(tab_name, None)
if tab and tab._allowed and (tab._enabled or allow_disabled):
return tab
return None
[docs] def get_loaded_tabs(self):
return [tab for tab in self._tabs.values() if self.get_tab(tab.slug)]
[docs] def get_selected_tab(self):
"""Returns the tab specific by the GET request parameter.
In the event that there is no GET request parameter, the value
of the query parameter is invalid, or the tab is not allowed/enabled,
the return value of this function is None.
"""
selected = self.request.GET.get(self.param_name, None)
if selected:
try:
tab_group, tab_name = selected.split(SEPARATOR)
except ValueError:
return None
if tab_group == self.get_id():
self._selected = self.get_tab(tab_name)
return self._selected
[docs]class Tab(html.HTMLElement):
"""A reusable interface for constructing a tab within a
:class:`~horizon.tabs.TabGroup`.
.. attribute:: name
The display name for the tab which will be rendered as the text for
the tab element in the HTML. Required.
.. attribute:: slug
The URL slug and id attribute for the tab. This should be unique for
a given tab group. Required.
.. attribute:: preload
Determines whether the contents of the tab should be rendered into
the page's HTML when the tab group is rendered, or whether it should
be loaded dynamically when the tab is selected. Default: ``True``.
.. attribute:: classes
A list of CSS classes which should be displayed on this tab.
.. attribute:: attrs
A dictionary of HTML attributes which should be rendered into the
markup for this tab.
.. attribute:: load
Read-only access to determine whether or not this tab's data should
be loaded immediately.
.. attribute:: permissions
A list of permission names which this tab requires in order to be
displayed. Defaults to an empty list (``[]``).
"""
name = None
slug = None
preload = True
_active = None
permissions = []
def __init__(self, tab_group, request=None):
super(Tab, self).__init__()
# Priority: constructor, class-defined, fallback
if not self.name:
raise ValueError("%s must have a name." % self.__class__.__name__)
self.name = six.text_type(self.name) # Force unicode.
if not self.slug:
raise ValueError("%s must have a slug." % self.__class__.__name__)
self.tab_group = tab_group
self.request = request
if request:
self._allowed = self.allowed(request) and (
self._has_permissions(request))
self._enabled = self.enabled(request)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.slug)
def _has_permissions(self, request):
return request.user.has_perms(self.permissions)
[docs] def is_active(self):
"""Method to access whether or not this tab is the active tab."""
if self._active is None:
self.tab_group._set_active_tab()
return self._active
@property
[docs] def load(self):
load_preloaded = self.preload or self.is_active()
return load_preloaded and self._allowed and self._enabled
@property
[docs] def data(self):
if getattr(self, "_data", None) is None:
self._data = self.get_context_data(self.request)
return self._data
@property
[docs] def data_loaded(self):
return getattr(self, "_data", None) is not None
[docs] def render(self):
"""Renders the tab to HTML using the
:meth:`~horizon.tabs.Tab.get_context_data` method and
the :meth:`~horizon.tabs.Tab.get_template_name` method.
If :attr:`~horizon.tabs.Tab.preload` is ``False`` and ``force_load``
is not ``True``, or
either :meth:`~horizon.tabs.Tab.allowed` or
:meth:`~horizon.tabs.Tab.enabled` returns ``False`` this method will
return an empty string.
"""
if not self.load:
return ''
try:
context = self.data
except exceptions.Http302:
raise
except Exception:
exc_type, exc_value, exc_traceback = sys.exc_info()
raise six.reraise(TemplateSyntaxError, exc_value, exc_traceback)
return render_to_string(self.get_template_name(self.request), context)
[docs] def get_id(self):
"""Returns the id for this tab. Defaults to
``"{{ tab_group.slug }}__{{ tab.slug }}"``.
"""
return SEPARATOR.join([self.tab_group.slug, self.slug])
[docs] def get_query_string(self):
return "=".join((self.tab_group.param_name, self.get_id()))
[docs] def get_default_classes(self):
"""Returns a list of the default classes for the tab. Defaults to
and empty list (``[]``), however additional classes may be added
depending on the state of the tab as follows:
If the tab is the active tab for the tab group, in which
the class ``"active"`` will be added.
If the tab is not enabled, the classes the class ``"disabled"``
will be added.
"""
default_classes = super(Tab, self).get_default_classes()
if self.is_active():
default_classes.extend(CSS_ACTIVE_TAB_CLASSES)
if not self._enabled:
default_classes.extend(CSS_DISABLED_TAB_CLASSES)
return default_classes
[docs] def get_template_name(self, request):
"""Returns the name of the template to be used for rendering this tab.
By default it returns the value of the ``template_name`` attribute
on the ``Tab`` class.
"""
if not hasattr(self, "template_name"):
raise AttributeError("%s must have a template_name attribute or "
"override the get_template_name method."
% self.__class__.__name__)
return self.template_name
[docs] def get_context_data(self, request, **kwargs):
"""This method should return a dictionary of context data used to
render the tab. Required.
"""
return kwargs
[docs] def enabled(self, request):
"""Determines whether or not the tab should be accessible
(e.g. be rendered into the HTML on load and respond to a click event).
If a tab returns ``False`` from ``enabled`` it will ignore the value
of ``preload`` and only render the HTML of the tab after being clicked.
The default behavior is to return ``True`` for all cases.
"""
return True
[docs] def allowed(self, request):
"""Determines whether or not the tab is displayed.
Tab instances can override this method to specify conditions under
which this tab should not be shown at all by returning ``False``.
The default behavior is to return ``True`` for all cases.
"""
return True
[docs] def post(self, request, *args, **kwargs):
"""Handles POST data sent to a tab.
Tab instances can override this method to have tab-specific POST logic
without polluting the TabView code.
The default behavior is to ignore POST data.
"""
pass
[docs]class TableTab(Tab):
"""A :class:`~horizon.tabs.Tab` class which knows how to deal with
:class:`~horizon.tables.DataTable` classes rendered inside of it.
This distinct class is required due to the complexity involved in handling
both dynamic tab loading, dynamic table updating and table actions all
within one view.
.. attribute:: table_classes
An iterable containing the :class:`~horizon.tables.DataTable` classes
which this tab will contain. Equivalent to the
:attr:`~horizon.tables.MultiTableView.table_classes` attribute on
:class:`~horizon.tables.MultiTableView`. For each table class you
need to define a corresponding ``get_{{ table_name }}_data`` method
as with :class:`~horizon.tables.MultiTableView`.
"""
table_classes = None
def __init__(self, tab_group, request):
super(TableTab, self).__init__(tab_group, request)
if not self.table_classes:
class_name = self.__class__.__name__
raise NotImplementedError("You must define a table_class "
"attribute on %s" % class_name)
# Instantiate our table classes but don't assign data yet
table_instances = [(table._meta.name,
table(request, **tab_group.kwargs))
for table in self.table_classes]
self._tables = OrderedDict(table_instances)
self._table_data_loaded = False
[docs] def load_table_data(self):
"""Calls the ``get_{{ table_name }}_data`` methods for each table class
and sets the data on the tables.
"""
# We only want the data to be loaded once, so we track if we have...
if not self._table_data_loaded:
for table_name, table in self._tables.items():
# Fetch the data function.
func_name = "get_%s_data" % table_name
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 "
"on %s." % (func_name, cls_name))
# Load the data.
table.data = data_func()
table._meta.has_prev_data = self.has_prev_data(table)
table._meta.has_more_data = self.has_more_data(table)
# Mark our data as loaded so we don't run the loaders again.
self._table_data_loaded = True
[docs] def get_context_data(self, request, **kwargs):
"""Adds a ``{{ table_name }}_table`` item to the context for each table
in the :attr:`~horizon.tabs.TableTab.table_classes` attribute.
If only one table class is provided, a shortcut ``table`` context
variable is also added containing the single table.
"""
context = super(TableTab, self).get_context_data(request, **kwargs)
# If the data hasn't been manually loaded before now,
# make certain it's loaded before setting the context.
self.load_table_data()
for table_name, table in self._tables.items():
# If there's only one table class, add a shortcut name as well.
if len(self.table_classes) == 1:
context["table"] = table
context["%s_table" % table_name] = table
return context
[docs] def has_prev_data(self, table):
return False
[docs] def has_more_data(self, table):
return False