区分是课程邀请，还是意见反馈

app/controllers/wechats_controller.rb

@@ -8,7 +8,11 @@ class WechatsController < ActionController::Base
   # default text responder when no other match
   on :text do |request, content|
       #邀请码
+    if join_request
       sendBindClass(request, {invite_code: content})
+    else
+      request.reply.text '您的意见已收到，感谢您的反馈！'
+    end
   end
 
   # When receive 'help', will trigger this responder
@@ -142,6 +146,11 @@ class WechatsController < ActionController::Base
     end
   end
 
+  def join_request(request)
+    openid = request[:FromUserName]
+    wl = WechatLog.where(openid: openid).order('id desc').first
+    wl && JSON(wl.request_raw)["EventKey"] == 'JOIN_CLASS'
+  end
 
   def sendBindClass(request, params)
     begin

app/models/wechat_log.rb

@@ -0,0 +1,4 @@
+#coding=utf-8
+#
+class WechatLog < ActiveRecord::Base
+end

db/migrate/20160709015740_add_index_openid_to_wechat_logs.rb

@@ -0,0 +1,5 @@
+class AddIndexOpenidToWechatLogs < ActiveRecord::Migration
+  def change
+    add_index(:wechat_logs, :openid)
+  end
+end

db/schema.rb

@@ -11,7 +11,8 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20160708091258) do
+ActiveRecord::Schema.define(:version => 20160709015740) do
+
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
     t.string   "act_type",                                :null => false
@@ -2185,6 +2186,8 @@ ActiveRecord::Schema.define(:version => 20160708091258) do
     t.datetime "created_at",   :null => false
   end
 
+  add_index "wechat_logs", ["openid"], :name => "index_wechat_logs_on_openid"
+
   create_table "wiki_content_versions", :force => true do |t|
     t.integer  "wiki_content_id",                                       :null => false
     t.integer  "page_id",                                               :null => false