Code Cleanup: Usage of Polymorphic User instead of ExternalUser and InternalUser

Renamed requestor_user_id -> user_id
Index of request_for_comments now returns the n (5?) newest requests per user. Solved via sliding windows in postgres, code added to model.
Added route to /my_request_for_comments/ that shows all requests for the current user.
Changed view from ERB to slim

app/controllers/comments_controller.rb

@@ -41,13 +41,9 @@ class CommentsController < ApplicationController
       # if the user is internal, set the name
 
       @comments.map{|comment|
-        if(comment.user_type == 'InternalUser')
-          comment.username = InternalUser.find(comment.user_id).name
-        elsif(comment.user_type == 'ExternalUser')
-          comment.username = ExternalUser.find(comment.user_id).name
+          comment.username = comment.user.name
         # alternative: # if the user is external, fetch the displayname from xikolo
         # Xikolo::UserClient.get(comment.user_id.to_s)[:display_name]
-        end
       }
     else
       @comments = Comment.all.limit(0) #we need an empty relation here

app/controllers/request_for_comments_controller.rb

@@ -11,11 +11,15 @@ class RequestForCommentsController < ApplicationController
   # GET /request_for_comments
   # GET /request_for_comments.json
   def index
-    # @request_for_comments = RequestForComment.all
-    @request_for_comments = RequestForComment.all.order('created_at DESC').limit(50)
+    @request_for_comments = RequestForComment.last_per_user(2).paginate(page: params[:page])
     authorize!
   end
 
+  def get_my_comment_requests
+    @request_for_comments = RequestForComment.where(user_id: current_user.id).order('created_at DESC').paginate(page: params[:page])
+    render 'index'
+  end
+
   # GET /request_for_comments/1
   # GET /request_for_comments/1.json
   def show
@@ -66,6 +70,6 @@ class RequestForCommentsController < ApplicationController
 
     # Never trust parameters from the scary internet, only allow the white list through.
     def request_for_comment_params
-      params.require(:request_for_comment).permit(:exercise_id, :file_id, :requested_at).merge(requestor_user_id: current_user.id, user_type: current_user.class.name)
+      params.require(:request_for_comment).permit(:exercise_id, :file_id, :requested_at).merge(user_id: current_user.id, user_type: current_user.class.name)
     end
 end

app/models/comment.rb

@@ -4,4 +4,5 @@ class Comment < ActiveRecord::Base
   attr_accessor :username
 
   belongs_to :file, class: CodeOcean::File
+  belongs_to :user, polymorphic: true
 end

app/models/request_for_comment.rb

@@ -1,7 +1,20 @@
 class RequestForComment < ActiveRecord::Base
+  belongs_to :exercise
+  belongs_to :file, class: CodeOcean::File
+  belongs_to :user, polymorphic: true
+
   before_create :set_requested_timestamp
 
+    def self.last_per_user(n = 5)
+      from("(#{row_number_user_sql}) as request_for_comments").where("row_number <= ?", n)
+    end
+
     def set_requested_timestamp
         self.requested_at = Time.now
     end
+
+    private
+    def self.row_number_user_sql
+      select("id, user_id, exercise_id, file_id, requested_at, created_at, updated_at, user_type, row_number() OVER (PARTITION BY user_id ORDER BY created_at DESC) as row_number").to_sql
+    end
 end

app/views/request_for_comments/_form.html.erb

@@ -12,8 +12,8 @@
   <% end %>
 
   <div class="field">
-    <%= f.label :requestor_user_id %><br>
-    <%= f.number_field :requestor_user_id %>
+    <%= f.label :user_id %><br>
+    <%= f.number_field :user_id %>
   </div>
   <div class="field">
     <%= f.label :exercise_id %><br>

app/views/request_for_comments/index.html.erb

@@ -1,21 +0,0 @@
-<h1><%= t('exercises.implement.comment.listing') %></h1>
-
-<div class="list-group">
-  <% @request_for_comments.each do |request_for_comment| %>
-    <a href="<%= request_for_comment_path(request_for_comment) %>" class="list-group-item">
-      <h4 class="list-group-item-heading"><%= Exercise.find(request_for_comment.exercise_id) %></h4>
-      <p class="list-group-item-text">
-        <%
-           user = nil
-           if (request_for_comment.user_type == 'InternalUser')
-             user = InternalUser.find(request_for_comment.requestor_user_id)
-           else
-             user = ExternalUser.find(request_for_comment.requestor_user_id)
-           end
-        %>
-
-          <%= user %> | <%= request_for_comment.requested_at %>
-      </p>
-    </a>
-  <% end %>
-</div>

app/views/request_for_comments/index.html.slim

@@ -0,0 +1,19 @@
+h1 = RequestForComment.model_name.human(count: 2)
+
+.table-responsive
+  table.table
+    thead
+      tr
+        th = t('activerecord.attributes.request_for_comments.exercise')
+        th = t('activerecord.attributes.request_for_comments.execution_environment')
+        th = t('activerecord.attributes.request_for_comments.username')
+        th = t('activerecord.attributes.request_for_comments.requested_at')
+    tbody
+      - @request_for_comments.each do |request_for_comment|
+        tr data-id=request_for_comment.id
+          td = link_to(request_for_comment.exercise.title, request_for_comment)
+          td = request_for_comment.exercise.execution_environment
+          td = request_for_comment.user.name
+          td = request_for_comment.requested_at
+
+= render('shared/pagination', collection: @request_for_comments)

app/views/request_for_comments/index.json.jbuilder

@@ -1,4 +1,4 @@
 json.array!(@request_for_comments) do |request_for_comment|
-  json.extract! request_for_comment, :id, :requestor_user_id, :exercise_id, :file_id, :requested_at, :user_type
+  json.extract! request_for_comment, :id, :user_id, :exercise_id, :file_id, :requested_at, :user_type
   json.url request_for_comment_url(request_for_comment, format: :json)
 end

app/views/request_for_comments/show.html.erb

@@ -2,12 +2,9 @@
   <h4 class="list-group-item-heading"><%= Exercise.find(@request_for_comment.exercise_id) %></h4>
   <p class="list-group-item-text">
       <%
-         user = nil
-         if (@request_for_comment.user_type == 'InternalUser')
-           user = InternalUser.find(@request_for_comment.requestor_user_id)
-         else
-           user = ExternalUser.find(@request_for_comment.requestor_user_id)
-         end
+
+           user = @request_for_comment.user
+
       %>
     <%= user %> | <%= @request_for_comment.requested_at %>
   </p>

app/views/request_for_comments/show.json.jbuilder

@@ -1 +1 @@
-json.extract! @request_for_comment, :id, :requestor_user_id, :exercise_id, :file_id, :requested_at, :created_at, :updated_at, :user_type
+json.extract! @request_for_comment, :id, :user_id, :exercise_id, :file_id, :requested_at, :created_at, :updated_at, :user_type

config/locales/de.yml

@@ -73,6 +73,11 @@ de:
         password: Passwort
         password_confirmation: Passwort-Bestätigung
         role: Rolle
+      request_for_comments:
+        exercise: Aufgabe
+        execution_environment: Sprache
+        username: Benutzername
+        requested_at: Angefragezeitpunkt
       submission:
         cause: Anlass
         code: Code
@@ -176,7 +181,7 @@ de:
       run: Ausführen
       run_failure: Ihr Code konnte nicht auf der Plattform ausgeführt werden.
       run_success: Ihr Code wurde auf der Plattform ausgeführt.
-      requestComments: Rückmeldung erbitten
+      requestComments: Kommentare erbitten
       save: Speichern
       score: Bewerten
       start_over: Von vorne anfangen
@@ -272,6 +277,9 @@ de:
       reset_password:
         body: 'Bitte besuchen Sie %{link}, sofern Sie Ihr Passwort zurücksetzen wollen.'
         subject: Anweisungen zum Zurücksetzen Ihres Passworts
+  request_for_comments:
+    index:
+      get_my_comment_requests: Meine Kommentaranfragen
   sessions:
     create:
       failure: Fehlerhafte E-Mail oder Passwort.

config/locales/en.yml

@@ -73,6 +73,11 @@ en:
         password: Password
         password_confirmation: Passwort Confirmation
         role: Role
+      request_for_comments:
+        exercise: Exercise
+        execution_environment: Language
+        username: Username
+        requested_at: Request Date
       submission:
         cause: Cause
         code: Code
@@ -272,6 +277,9 @@ en:
       reset_password:
         body: 'Please visit %{link} if you want to reset your password.'
         subject: Password reset instructions
+  request_for_comments:
+    index:
+      get_my_comment_requests: My Requests for Comments
   sessions:
     create:
       failure: Invalid email or password.

config/routes.rb

@@ -2,6 +2,7 @@ FILENAME_REGEXP = /[\w\.]+/ unless Kernel.const_defined?(:FILENAME_REGEXP)
 
 Rails.application.routes.draw do
   resources :request_for_comments
+    get '/my_request_for_comments', as: 'my_request_for_comments', to: 'request_for_comments#get_my_comment_requests'
   resources :comments, except: [:destroy] do
     collection do
       delete :destroy

db/migrate/20150903152727_remove_requestor_from_request_for_comments.rb

@@ -0,0 +1,5 @@
+class RemoveRequestorFromRequestForComments < ActiveRecord::Migration
+  def change
+    rename_column :request_for_comments, :requestor_user_id, :user_id
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20150818142251) do
+ActiveRecord::Schema.define(version: 20150903152727) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -171,7 +171,7 @@ ActiveRecord::Schema.define(version: 20150818142251) do
   add_index "internal_users_teams", ["team_id"], name: "index_internal_users_teams_on_team_id", using: :btree
 
   create_table "request_for_comments", force: true do |t|
-    t.integer  "requestor_user_id", null: false
+    t.integer  "user_id",      null: false
     t.integer  "exercise_id",  null: false
     t.integer  "file_id",      null: false
     t.datetime "requested_at"