cache wiki page hierarchy

app/assets/javascripts/tree_menu.js

@@ -28,11 +28,20 @@
 
 (function ($) {
   "use strict";
+
   $(function() {
+    // set selected page for menu tree if provided.
+    $('[data-selected-page].tree-menu--container').each(function(_i, tree){
+      var selectedPage = $(tree).data('selected-page');
+      if (selectedPage) {
+        $('[slug=' + selectedPage + ']', tree).toggleClass('-selected', true);
+      }
+    });
+
+    // set click handlers for expanding and collapsing tree nodes
     $('.pages-hierarchy.-with-hierarchy .tree-menu--hierarchy-span').click(function (event) {
       var target = $(event.target);
       var targetList = target.closest('.-with-hierarchy');
-      console.log("click was triggered", targetList);
       if (targetList.hasClass('-hierarchy-collapsed')) {
         targetList.addClass('-hierarchy-expanded');
         targetList.removeClass('-hierarchy-collapsed');

app/assets/stylesheets/layout/_tree_menu.sass

@@ -56,7 +56,6 @@ div.wiki ul.pages-hierarchy,
     .-with-hierarchy
       padding-left: 18px
 
-
   &.-hierarchy-collapsed > li
     > .tree-menu--item > .tree-menu--hierarchy-span > .tree-menu--hierarchy-indicator > .tree-menu--hierarchy-indicator-icon
       @include icon-common

app/helpers/application_helper.rb

@@ -571,7 +571,7 @@ module ApplicationHelper
   private
 
   def render_hierarchy_item(page, is_parent, options = {})
-    content_tag(:span, class: hierarchy_item_classes(page)) do
+    content_tag(:span, class: 'tree-menu--item', slug: page.slug) do
       hierarchy_span_content = nil
       if is_parent
         hierarchy_span_content = if is_parent
@@ -596,14 +596,6 @@ module ApplicationHelper
     end
   end
 
-  def hierarchy_item_classes(page)
-    item_classes = 'tree-menu--item'
-    if @page.present? && @page.id == page.id
-      item_classes += ' -selected'
-    end
-    item_classes
-  end
-
   def render_leaf_indicator
     content_tag(:span, tabindex: 0, class: 'tree-menu--leaf-indicator') do
       content_tag(:span,

app/models/wiki_page.rb

@@ -31,7 +31,7 @@ require 'diff'
 require 'enumerator'
 
 class WikiPage < ActiveRecord::Base
-  belongs_to :wiki
+  belongs_to :wiki, touch: true
   has_one :project, through: :wiki
   has_one :content, class_name: 'WikiContent', foreign_key: 'page_id', dependent: :destroy
   acts_as_attachable delete_permission: :delete_wiki_pages_attachments

app/views/wiki/_menu_pages_tree.html.erb

@@ -1,6 +1,8 @@
-<div class="menu-wiki-pages-tree">
-  <div class="main-menu--segment-header ellipsis"><%= t('label_table_of_contents') %></div>
-  <% pages = @project.wiki.pages.with_updated_on.order('title').includes(wiki: :project)
-     pages_by_parent_id = pages.group_by(&:parent_id) %>
-  <%= render_page_hierarchy(pages_by_parent_id, nil, timestamp: false) %>
+<div class="menu-wiki-pages-tree tree-menu--container" data-selected-page="<%= @page.present? ? @page.slug : '' %>">
+  <% cache @project.wiki do %>
+    <div class="main-menu--segment-header ellipsis"><%= t('label_table_of_contents') %></div>
+    <% pages = @project.wiki.pages.order('title').includes(wiki: :project)
+       pages_by_parent_id = pages.group_by(&:parent_id) %>
+    <%= render_page_hierarchy(pages_by_parent_id, nil, timestamp: false) %>
+  <% end %>
 </div>

db/migrate/20180518130559_add_timestamps_to_wiki.rb

@@ -0,0 +1,10 @@
+class AddTimestampsToWiki < ActiveRecord::Migration[5.1]
+  def change
+    add_timestamps :wikis, default: DateTime.now
+    change_column_default :wikis, :created_at, nil
+    change_column_default :wikis, :updated_at, nil
+
+    add_column :wiki_pages, :updated_at, :datetime, default: DateTime.now, null: false
+    change_column_default :wiki_pages, :updated_at, nil
+  end
+end