Add register_admin_menu_item hook for registering MenuItems globally

wagtail/wagtailadmin/menu.py

@@ -11,6 +11,8 @@ except ImportError:
 from django.utils.text import slugify
 from django.utils.html import format_html
 
+from wagtail.wagtailcore import hooks
+
 
 class MenuItem(object):
     def __init__(self, label, url, name=None, classnames='', attrs=None, order=1000):
@@ -29,3 +31,12 @@ class MenuItem(object):
         return format_html(
             """<li class="menu-{0}"><a href="{1}" class="{2}"{3}>{4}</a></li>""",
             self.name, self.url, self.classnames, self.attr_string, self.label)
+
+
+_menu_items = None
+def get_menu_items():
+    global _menu_items
+    if _menu_items is None:
+        _menu_items = [fn() for fn in hooks.get_hooks('register_admin_menu_item')]
+
+    return _menu_items

wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py

@@ -2,14 +2,11 @@ from __future__ import unicode_literals
 
 from django.conf import settings
 from django import template
-from django.core import urlresolvers
-from django.utils.translation import ugettext_lazy as _
-
-from wagtail.wagtailadmin.menu import MenuItem
 
 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_menu_items
 
 
 register = template.Library()
@@ -31,13 +28,7 @@ def explorer_subnav(nodes):
 
 @register.inclusion_tag('wagtailadmin/shared/main_nav.html', takes_context=True)
 def main_nav(context):
-    menu_items = [
-        MenuItem(_('Explorer'), urlresolvers.reverse('wagtailadmin_explore_root'),
-            classnames='icon icon-folder-open-inverse dl-trigger',
-            attrs={'data-explorer-menu-url': urlresolvers.reverse('wagtailadmin_explorer_nav')},
-            order=100),
-        MenuItem(_('Search'), urlresolvers.reverse('wagtailadmin_pages_search'), classnames='icon icon-search', order=200),
-    ]
+    menu_items = get_menu_items()[:]  # need to clone with [:] because the return value of get_menu_items is global, and construct_main_menu hooks will mutate it
 
     request = context['request']
 

wagtail/wagtailadmin/wagtail_hooks.py

@@ -0,0 +1,20 @@
+from django.core import urlresolvers
+from django.utils.translation import ugettext_lazy as _
+
+from wagtail.wagtailcore import hooks
+from wagtail.wagtailadmin.menu import MenuItem
+
+
+@hooks.register('register_admin_menu_item')
+def register_explorer_menu_item():
+    return MenuItem(
+        _('Explorer'), urlresolvers.reverse('wagtailadmin_explore_root'),
+        classnames='icon icon-folder-open-inverse dl-trigger',
+        attrs={'data-explorer-menu-url': urlresolvers.reverse('wagtailadmin_explorer_nav')},
+        order=100)
+
+@hooks.register('register_admin_menu_item')
+def register_search_menu_item():
+    return MenuItem(
+        _('Search'), urlresolvers.reverse('wagtailadmin_pages_search'),
+        classnames='icon icon-search', order=200)