add more like this to topic

app/cells/topics/sidebar_for_more_like_this.html.erb

@@ -0,0 +1,10 @@
+<% if @topics.present? %>
+<div class="nodes box clearfix">
+  <h2><%= t("topics.more_like_this") %></h2>
+  <ul>
+  <% for topic in @topics do %>
+    <li><%= link_to(truncate(topic.title, :length => 20), topic_path(topic), :title => topic.title) %></li>
+  <% end %>
+  </ul>
+</div>
+<% end %>

app/cells/topics_cell.rb

@@ -39,7 +39,19 @@ def sidebar_for_new_topic_node(args)
     @action = args[:action]
     render 
   end
-
+
+  # 相关类似话题, 取相关词出现最少3次，相关度最高的3篇
+  cache :sidebar_for_more_like_this, :expires_in => 1.day do |cell, args|
+    args[:topic].id
+  end
+  def sidebar_for_more_like_this(args)
+    @topics = args[:topic].more_like_this do
+      minimum_term_frequency 3
+      paginate :page => 1, :per_page => 3
+    end.results
+    render
+  end
+
   def reply_help_block(opts = {})
     @full = opts[:full] || false
     render

app/models/topic.rb

@@ -38,9 +38,9 @@ class Topic
   counter :hits, :default => 0
 
   searchable do
-    text :title, :stored => true
-    text :body, :stored => true
-    text :replies, :stored => true do
+    text :title, :stored => true, :more_like_this => true
+    text :body, :stored => true, :more_like_this => true
+    text :replies, :stored => true, :more_like_this => true do
       replies.map { |reply| reply.body }
     end
     integer :node_id, :user_id

app/views/topics/show.html.erb

@@ -8,6 +8,7 @@
 <% end %>
 <div class="sidebar">
     <%= render_cell :topics, :sidebar_for_new_topic_node, { :action => params[:action], :node => @node } %>
+    <%= render_cell :topics, :sidebar_for_more_like_this, { :topic => @topic} %>
 </div>
 
 <div class="content">

config/locales/topics.zh-CN.yml

@@ -21,4 +21,5 @@
     add_image: "上传图片"
     topic_was_deleted: "[该主题已被删除]"
     have_no_new_reply: "在你读过以后还没有新变化"
-    has_new_replies: "有新内容"
+    has_new_replies: "有新内容"
+    more_like_this: "相关贴子"

config/locales/topics.zh-TW.yml

@@ -22,3 +22,4 @@
     topic_was_deleted: "[該主題已被刪除]"
     have_no_new_reply: "在你讀過以後還沒有新回應"
     has_new_replies: "有新內容"
+    more_like_this: "相關話題"

solr/conf/solrconfig.xml

@@ -610,6 +610,7 @@
     </lst>
     -->
   </searchComponent>
+  <searchComponent name="mlt" class="org.apache.solr.handler.component.MoreLikeThisComponent" /> 
   <!-- A request handler utilizing the spellcheck component.  
   #############################################################################
   NOTE: This is purely as an example.  The whole purpose of the