do not use external_id for users; store id directly

Rakefile

@@ -26,7 +26,7 @@ namespace :test do
       
       commentable = Commentable.create!(commentable_type: "questions", commentable_id: "1")
 
-      user = User.create!(external_id: "1")
+      user = User.create!(id: "1")
 
       comment_thread = commentable.comment_threads.create!(title: "I can't solve this problem", body: "can anyone help me?", course_id: "1")
       comment_thread.author = user
@@ -78,7 +78,7 @@ namespace :db do
 
     level_limit = YAML.load_file("config/application.yml")["level_limit"]
 
-    user = User.create!(external_id: "1")
+    user = User.create!(id: "1")
 
     def generate_comments(commentable_type, commentable_id, level_limit, user)
       commentable = Commentable.create!(commentable_type: commentable_type, commentable_id: commentable_id)
@@ -115,7 +115,7 @@ namespace :db do
     puts "voting"
     users = []
     (1..10).each do |id|
-      users << User.find_or_create_by(external_id: id.to_s)
+      users << User.find_or_create_by(id: id.to_s)
     end
 
     CommentThread.all.each do |c|

app.rb

@@ -71,7 +71,7 @@ end
 post '/api/v1/commentables/:commentable_type/:commentable_id/comment_threads' do |commentable_type, commentable_id|
   commentable = Commentable.find_or_create_by(commentable_type: commentable_type, commentable_id: commentable_id)
   comment_thread = commentable.comment_threads.new(params.slice(*%w[title body course_id]))
-  comment_thread.author = User.find_or_create_by(external_id: params["user_id"])
+  comment_thread.author = User.find_or_create_by(id: params["user_id"])
   comment_thread.save!
   comment_thread.to_hash.to_json
 end
@@ -99,7 +99,7 @@ end
 post '/api/v1/comment_threads/:comment_thread_id/comments' do |comment_thread_id|
   comment_thread = CommentThread.find(comment_thread_id)
   comment = comment_thread.comments.new(params.slice(*%w[body course_id]))
-  comment.author = User.find_or_create_by(external_id: params["user_id"])
+  comment.author = User.find_or_create_by(id: params["user_id"])
   comment.save!
   comment.to_hash.to_json
 end
@@ -137,7 +137,7 @@ end
 post '/api/v1/comments/:comment_id' do |comment_id|
   comment = Comment.find(comment_id)
   sub_comment = comment.children.new(params.slice(*%w[body course_id]))
-  sub_comment.author = User.find_or_create_by(external_id: params["user_id"])
+  sub_comment.author = User.find_or_create_by(id: params["user_id"])
   sub_comment.save!
   sub_comment.to_hash.to_json
 end
@@ -156,7 +156,7 @@ end
 
 put '/api/v1/votes/comments/:comment_id/users/:user_id' do |comment_id, user_id|
   comment = Comment.find(comment_id)
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   user.vote(comment, params["value"].intern)
   Comment.find(comment_id).to_hash.to_json
 end
@@ -166,7 +166,7 @@ end
 
 delete '/api/v1/votes/comments/:comment_id/users/:user_id' do |comment_id, user_id|
   comment = Comment.find(comment_id)
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   user.unvote(comment)
   Comment.find(comment_id).to_hash.to_json
 end
@@ -176,7 +176,7 @@ end
 
 put '/api/v1/votes/comment_threads/:comment_thread_id/users/:user_id' do |comment_thread_id, user_id|
   comment_thread = CommentThread.find(comment_thread_id)
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   user.vote(comment_thread, params["value"].intern)
   CommentThread.find(comment_thread_id).to_hash.to_json
 end
@@ -186,7 +186,7 @@ end
 
 delete '/api/v1/votes/comment_threads/:comment_thread_id/users/:user_id' do |comment_thread_id, user_id|
   comment_thread = CommentThread.find(comment_thread_id)
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   user.unvote(comment_thread)
   CommentThread.find(comment_thread_id).to_hash.to_json
 end
@@ -195,7 +195,7 @@ end
 # get all subscribed feeds for the user
 
 get '/api/v1/users/:user_id/feeds' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   user.feeds.map(&:to_hash).to_json
 end
 
@@ -203,8 +203,8 @@ end
 # follow user
 
 post '/api/v1/users/:user_id/follow' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
-  followed_user = User.find_or_create_by(external_id: params[:user_id])
+  user = User.find_or_create_by(id: user_id)
+  followed_user = User.find_or_create_by(id: params[:user_id])
   user.follow(followed_user)
   user.to_hash.to_json
 end
@@ -213,8 +213,8 @@ end
 # unfollow user
 
 post '/api/v1/users/:user_id/unfollow' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
-  followed_user = User.find_or_create_by(external_id: params[:user_id])
+  user = User.find_or_create_by(id: user_id)
+  followed_user = User.find_or_create_by(id: params[:user_id])
   user.unfollow(followed_user)
   user.to_hash.to_json
 end
@@ -223,7 +223,7 @@ end
 # watch a commentable
 
 post '/api/v1/users/:user_id/watch/commentable' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   commentable = Commentable.find_or_create_by(commentable_type: params[:commentable_type],
                                               commentable_id: parasm[:commentable_id])
   user.watch_commentable(commentable)
@@ -234,7 +234,7 @@ end
 # unwatch a commentable
 
 post '/api/v1/users/:user_id/unwatch/commentable' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   commentable = Commentable.find_or_create_by(commentable_type: params[:commentable_type],
                                               commentable_id: parasm[:commentable_id])
   user.unwatch_commentable(commentable)
@@ -245,7 +245,7 @@ end
 # watch a comment thread
 
 post '/api/v1/users/:user_id/watch/comment_thread' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   comment_thread = CommentThread.find(params[:comment_thread_id])
   user.watch_comment_thread(comment_thread)
   user.to_hash.to_json
@@ -255,7 +255,7 @@ end
 # unwatch a comment thread
 
 post '/api/v1/users/:user_id/unwatch/comment_thread' do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
+  user = User.find_or_create_by(id: user_id)
   comment_thread = CommentThread.find(params[:comment_thread_id])
   user.unwatch_comment_thread(comment_thread)
   user.to_hash.to_json

models/comment.rb

@@ -47,7 +47,7 @@ class Comment
       self.class.hash_tree(subtree(sort: sort_by_parent_and_time)).first
     else
       as_document.slice(*%w[body course_id endorsed _id]).
-                  merge("user_id" => author.external_id).
+                  merge("user_id" => author.id).
                   merge("votes" => votes.slice(*%w[count up_count down_count point]))
     end
   end

models/comment_thread.rb

@@ -25,7 +25,7 @@ class CommentThread
   
   def to_hash(params={})
     doc = as_document.slice(*%w[title body course_id _id]).
-                      merge("user_id" => author.external_id).
+                      merge("user_id" => author.id).
                       merge("votes" => votes.slice(*%w[count up_count down_count point]))
     if params[:recursive]
       doc = doc.merge("children" => comments.map{|c| c.to_hash(recursive: true)})

models/user.rb

@@ -2,7 +2,7 @@ class User
   include Mongoid::Document
   include Mongo::Voter
 
-  field :external_id, type: String
+  identity type: String
   
   has_many :comments
   has_many :comment_threads, inverse_of: :author
@@ -11,15 +11,8 @@ class User
   has_and_belongs_to_many :followers, class_name: "User", inverse_of: :followings
   has_and_belongs_to_many :followings, class_name: "User", inverse_of: :followers
 
-  attr_accessible :external_id
-
-  validates_uniqueness_of :external_id
-  validates_presence_of :external_id
-
-  index :external_id, unique: true
-
   def to_hash(params={})
-    as_document.slice(*%w[_id external_id])
+    as_document.slice(*%w[_id])
   end
 
   def follow(user)

spec/app_spec.rb

@@ -18,7 +18,7 @@ def init_without_feeds
   commentable = Commentable.new(commentable_type: "questions", commentable_id: "1")
   commentable.save!
 
-  user = User.create!(external_id: "1")
+  user = User.create!(id: "1")
 
   comment_thread = commentable.comment_threads.new(title: "I can't solve this problem", body: "can anyone help me?", course_id: "1")
   comment_thread.author = user
@@ -58,7 +58,7 @@ def init_without_feeds
   comment1.author = user
   comment1.save!
 
-  users = (2..10).map{|id| User.find_or_create_by(external_id: id.to_s)}
+  users = (2..10).map{|id| User.find_or_create_by(id: id.to_s)}
 
   Comment.all.each do |c|
     user.vote(c, :up) # make the first user always vote up for convenience
@@ -163,13 +163,13 @@ describe "app" do
       it "create a comment to the comment thread" do
         comment_thread = CommentThread.first.to_hash(recursive: true)
         user = User.first
-        post "/api/v1/comment_threads/#{comment_thread["_id"]}/comments", body: "new comment", course_id: "1", user_id: User.first.external_id
+        post "/api/v1/comment_threads/#{comment_thread["_id"]}/comments", body: "new comment", course_id: "1", user_id: User.first.id
         last_response.should be_ok
         changed_thread = CommentThread.find(comment_thread["_id"]).to_hash(recursive: true)
         changed_thread["children"].length.should == comment_thread["children"].length + 1
         comment = changed_thread["children"].select{|c| c["body"] == "new comment"}.first
         comment.should_not be_nil
-        comment["user_id"].should == user.external_id
+        comment["user_id"].should == user.id
       end
     end
     describe "DELETE /api/v1/comment_threads/:comment_thread_id" do
@@ -223,13 +223,13 @@ describe "app" do
       it "create a sub comment to the comment" do
         comment = Comment.first.to_hash(recursive: true)
         user = User.first
-        post "/api/v1/comments/#{comment["_id"]}", body: "new comment", course_id: "1", user_id: User.first.external_id
+        post "/api/v1/comments/#{comment["_id"]}", body: "new comment", course_id: "1", user_id: User.first.id
         last_response.should be_ok
         changed_comment = Comment.find(comment["_id"]).to_hash(recursive: true)
         changed_comment["children"].length.should == comment["children"].length + 1
         subcomment = changed_comment["children"].select{|c| c["body"] == "new comment"}.first
         subcomment.should_not be_nil
-        subcomment["user_id"].should == user.external_id       
+        subcomment["user_id"].should == user.id
       end
     end
     describe "DELETE /api/v1/comments/:comment_id" do
@@ -251,7 +251,7 @@ describe "app" do
         comment = Comment.first
         prev_up_votes = comment.up_votes_count
         prev_down_votes = comment.down_votes_count
-        put "/api/v1/votes/comments/#{comment.id}/users/#{user.external_id}", value: "down"
+        put "/api/v1/votes/comments/#{comment.id}/users/#{user.id}", value: "down"
         comment = Comment.find(comment.id)
         comment.up_votes_count.should == prev_up_votes - 1
         comment.down_votes_count.should == prev_down_votes + 1
@@ -263,7 +263,7 @@ describe "app" do
         comment = Comment.first
         prev_up_votes = comment.up_votes_count
         prev_down_votes = comment.down_votes_count
-        delete "/api/v1/votes/comments/#{comment.id}/users/#{user.external_id}"
+        delete "/api/v1/votes/comments/#{comment.id}/users/#{user.id}"
         comment = Comment.find(comment.id)
         comment.up_votes_count.should == prev_up_votes - 1
         comment.down_votes_count.should == prev_down_votes
@@ -275,7 +275,7 @@ describe "app" do
         comment_thread = CommentThread.first
         prev_up_votes = comment_thread.up_votes_count
         prev_down_votes = comment_thread.down_votes_count
-        put "/api/v1/votes/comment_threads/#{comment_thread.id}/users/#{user.external_id}", value: "down"
+        put "/api/v1/votes/comment_threads/#{comment_thread.id}/users/#{user.id}", value: "down"
         comment_thread = CommentThread.find(comment_thread.id)
         comment_thread.up_votes_count.should == prev_up_votes - 1
         comment_thread.down_votes_count.should == prev_down_votes + 1
@@ -287,7 +287,7 @@ describe "app" do
         comment_thread = CommentThread.first
         prev_up_votes = comment_thread.up_votes_count
         prev_down_votes = comment_thread.down_votes_count
-        delete "/api/v1/votes/comment_threads/#{comment_thread.id}/users/#{user.external_id}"
+        delete "/api/v1/votes/comment_threads/#{comment_thread.id}/users/#{user.id}"
         comment_thread = CommentThread.find(comment_thread.id)
         comment_thread.up_votes_count.should == prev_up_votes - 1
         comment_thread.down_votes_count.should == prev_down_votes