Fix selecting current menu item according to menu layout

djangocms_blog/menu.py

@@ -1,21 +1,34 @@
 # -*- coding: utf-8 -*-
 from __future__ import absolute_import, print_function, unicode_literals
 
+from cms.apphook_pool import apphook_pool
 from cms.menu_bases import CMSAttachMenu
+from django.core.urlresolvers import resolve
 from django.db.models.signals import post_delete, post_save
 from django.utils.translation import get_language_from_request, ugettext_lazy as _
-from menus.base import NavigationNode
+from menus.base import Modifier, NavigationNode
 from menus.menu_pool import menu_pool
 
 from .cms_appconfig import BlogConfig
 from .models import BlogCategory, Post
-from .settings import MENU_TYPE_CATEGORIES, MENU_TYPE_COMPLETE, MENU_TYPE_POSTS
+from .settings import MENU_TYPE_CATEGORIES, MENU_TYPE_COMPLETE, MENU_TYPE_POSTS, get_setting
 
 
 class BlogCategoryMenu(CMSAttachMenu):
+    """
+    Main menu class
+
+    Handles all types of blog menu
+    """
     name = _('Blog menu')
 
     def get_nodes(self, request):
+        """
+        Generates the nodelist
+
+        :param request:
+        :return: list of nodes
+        """
         nodes = []
 
         language = get_language_from_request(request, check_path=True)
@@ -75,7 +88,44 @@ class BlogCategoryMenu(CMSAttachMenu):
 menu_pool.register_menu(BlogCategoryMenu)
 
 
+class BlogNavModifier(Modifier):
+    """
+    This navigation modifier makes sure that when
+    a particular blog post is viewed,
+    a corresponding category is selected in menu
+    """
+    def modify(self, request, nodes, namespace, root_id, post_cut, breadcrumb):
+        app = None
+        config = None
+        if getattr(request, 'current_page', None) and request.current_page.application_urls:
+            app = apphook_pool.get_apphook(request.current_page.application_urls)
+
+        if app and app.app_config:
+            namespace = resolve(request.path).namespace
+            config = app.get_config(namespace)
+        if config and config.menu_structure != MENU_TYPE_CATEGORIES:
+            return nodes
+        if post_cut:
+            return nodes
+        current_post = getattr(request, get_setting('CURRENT_POST_IDENTIFIER'), None)
+        category = None
+        if current_post and current_post.__class__ == Post:
+            category = current_post.categories.first()
+        if not category:
+            return nodes
+
+        for node in nodes:
+            if '%s-%s' % (category.__class__.__name__, category.pk) == node.id:
+                node.selected = True
+        return nodes
+
+menu_pool.register_modifier(BlogNavModifier)
+
+
 def clear_menu_cache(**kwargs):
+    """
+    Empty menu cache when saving categories
+    """
     menu_pool.clear(all=True)
 
 post_save.connect(clear_menu_cache, sender=BlogCategory)