Refactor logic for registering menu items into a Menu class, so that it can be re-used for the settings menu

wagtail/wagtailadmin/menu.py

@@ -8,10 +8,9 @@ try:
 except ImportError:
     from django.forms.util import flatatt
 
-from django.conf import settings
-from django.forms import MediaDefiningClass
+from django.forms import MediaDefiningClass, Media
 from django.utils.text import slugify
-from django.utils.html import format_html, format_html_join
+from django.utils.html import format_html
 
 from wagtail.wagtailcore import hooks
 
@@ -42,15 +41,31 @@ class MenuItem(with_metaclass(MediaDefiningClass)):
             self.name, self.url, self.classnames, self.attr_string, self.label)
 
 
-_master_menu_item_list = None
-def get_master_menu_item_list():
-    """
-    Return the list of menu items registered with the 'register_admin_menu_item' hook.
-    This is the "master list" because the final admin menu may vary per request
-    according to the value of is_shown() and the construct_main_menu hook.
-    """
-    global _master_menu_item_list
-    if _master_menu_item_list is None:
-        _master_menu_item_list = [fn() for fn in hooks.get_hooks('register_admin_menu_item')]
+class Menu(object):
+    def __init__(self, hook_name):
+        self.hook_name = hook_name
+        # _registered_menu_items will be populated on first access to the
+        # registered_menu_items property. We can't populate it in __init__ because
+        # we can't rely on all hooks modules to have been imported at the point that
+        # we create the admin_menu and settings_menu instances
+        self._registered_menu_items = None
 
-    return _master_menu_item_list
+    @property
+    def registered_menu_items(self):
+        if self._registered_menu_items is None:
+            self._registered_menu_items = [fn() for fn in hooks.get_hooks(self.hook_name)]
+        return self._registered_menu_items
+
+    def menu_items_for_request(self, request):
+        return [item for item in self.registered_menu_items if item.is_shown(request)]
+
+    @property
+    def media(self):
+        media = Media()
+        for item in self.registered_menu_items:
+            media += item.media
+        return media
+
+
+admin_menu = Menu(hook_name='register_admin_menu_item')
+settings_menu = Menu(hook_name='register_settings_menu_item')

wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py

@@ -2,12 +2,11 @@ from __future__ import unicode_literals
 
 from django.conf import settings
 from django import template
-from django.forms import Media
 
 from wagtail.wagtailcore import hooks
 from wagtail.wagtailcore.models import get_navigation_menu_items, UserPagePermissionsProxy, PageViewRestriction
 from wagtail.wagtailcore.utils import camelcase_to_underscore
-from wagtail.wagtailadmin.menu import get_master_menu_item_list
+from wagtail.wagtailadmin.menu import admin_menu
 
 
 register = template.Library()
@@ -30,7 +29,7 @@ def explorer_subnav(nodes):
 @register.inclusion_tag('wagtailadmin/shared/main_nav.html', takes_context=True)
 def main_nav(context):
     request = context['request']
-    menu_items = [item for item in get_master_menu_item_list() if item.is_shown(request)]
+    menu_items = admin_menu.menu_items_for_request(request)
 
     for fn in hooks.get_hooks('construct_main_menu'):
         fn(request, menu_items)
@@ -42,11 +41,7 @@ def main_nav(context):
 
 @register.simple_tag
 def main_nav_js():
-    media = Media()
-    for item in get_master_menu_item_list():
-        media += item.media
-
-    return media['js']
+    return admin_menu.media['js']
 
 
 @register.filter("ellipsistrim")