/wiki_pages: sort autocomplete by post count.

* Add search[order]=post_count param to /wiki_pages.
* Make autocomplete do a prefix match ordered by post count, so that it
  works the same way that tag autocomplete does elsewhere.

app/assets/javascripts/wiki_pages.js

@@ -20,8 +20,9 @@
         $.ajax({
           url: "/wiki_pages.json",
           data: {
-            "search[title]": "*" + req.term + "*",
+            "search[title]": req.term + "*",
             "search[hide_deleted]": "Yes",
+            "search[order]": "post_count",
             "limit": 10
           },
           method: "get",

app/controllers/wiki_pages_controller.rb

@@ -15,7 +15,7 @@ class WikiPagesController < ApplicationController
   end
 
   def index
-    @wiki_pages = WikiPage.search(params[:search]).order("updated_at desc").paginate(params[:page], :limit => params[:limit], :search_count => params[:search])
+    @wiki_pages = WikiPage.search(params[:search]).paginate(params[:page], :limit => params[:limit], :search_count => params[:search])
     respond_with(@wiki_pages) do |format|
       format.html do
         if params[:page].nil? || params[:page].to_i == 1

app/models/wiki_page.rb

@@ -79,10 +79,15 @@ class WikiPage < ActiveRecord::Base
       end
 
       params[:order] ||= params.delete(:sort)
-      if params[:order] == "time" || params[:order] == "Date"
+      case params[:order]
+      when "time"
         q = q.order("updated_at desc")
-      elsif params[:order] == "title" || params[:order] == "Name"
+      when "title"
         q = q.order("title")
+      when "post_count"
+        q = q.joins(:tag).order("tags.post_count desc")
+      else
+        q = q.order("updated_at desc")
       end
 
       q

app/views/wiki_pages/search.html.erb

@@ -13,7 +13,7 @@
 
       <div class="input">
         <label for="search_order">Order</label>
-        <%= select "search", "order", ["Name", "Date"] %>
+        <%= select "search", "order", [%w[Name title], %w[Date time], %w[Posts post_count]] %>
       </div>
 
       <div class="input">