locks for http://stackoverflow.com/questions/7749039/how-do-i-lock-re…

…cords-in-rails-3-for-a-specific-amount-of-time

app/controllers/posts_controller.rb

@@ -0,0 +1,88 @@
+class PostsController < ApplicationController
+  before_filter :authenticate_user!
+
+  # GET /posts
+  # GET /posts.xml
+  def index
+    @posts = Post.all
+
+    respond_to do |format|
+      format.html # index.html.erb
+      format.xml  { render :xml => @posts }
+    end
+  end
+
+  # GET /posts/1
+  # GET /posts/1.xml
+  def show
+    @post = Post.find(params[:id])
+
+    respond_to do |format|
+      format.html # show.html.erb
+      format.xml  { render :xml => @post }
+    end
+  end
+
+  # GET /posts/new
+  # GET /posts/new.xml
+  def new
+    @post = Post.new
+
+    respond_to do |format|
+      format.html # new.html.erb
+      format.xml  { render :xml => @post }
+    end
+  end
+
+  # GET /posts/1/edit
+  def edit
+    @post = Post.find(params[:id])
+    @post.user = current_user
+    @post.lock! unless @post.locked?
+  end
+
+  # POST /posts
+  # POST /posts.xml
+  def create
+    @post = Post.new(params[:post])
+
+    respond_to do |format|
+      if @post.save
+        format.html { redirect_to(@post, :notice => 'Post was successfully created.') }
+        format.xml  { render :xml => @post, :status => :created, :location => @post }
+      else
+        format.html { render :action => "new" }
+        format.xml  { render :xml => @post.errors, :status => :unprocessable_entity }
+      end
+    end
+  end
+
+  # PUT /posts/1
+  # PUT /posts/1.xml
+  def update
+    @post = Post.find(params[:id])
+    @post.user = current_user
+
+    respond_to do |format|
+      if @post.update_attributes(params[:post])
+        format.html { redirect_to(@post, :notice => 'Post was successfully updated.') }
+        format.xml  { head :ok }
+      else
+        format.html { render :action => "edit" }
+        format.xml  { render :xml => @post.errors, :status => :unprocessable_entity }
+      end
+    end
+  end
+
+  # DELETE /posts/1
+  # DELETE /posts/1.xml
+  def destroy
+    @post = Post.find(params[:id])
+    @post.destroy
+
+    respond_to do |format|
+      format.html { redirect_to(posts_url) }
+      format.xml  { head :ok }
+    end
+  end
+end

app/models/lock.rb

@@ -0,0 +1,4 @@
+class Lock < ActiveRecord::Base
+  belongs_to :user
+  belongs_to :lockable, polymorphic: true
+end

app/models/post.rb

@@ -0,0 +1,26 @@
+class Post < ActiveRecord::Base
+  attr_accessor :user
+  has_many :locks, as: :lockable
+  validate :check_lock
+
+  def lock
+    @lock ||= self.locks.find(:first, order: 'created_at DESC')
+  end
+
+  def lock!
+    self.locks << Lock.new(user: @user) if @user
+  end
+
+  def locked?
+    return false unless self.lock
+    true if self.lock.created_at > 1.hour.ago
+  end
+
+  private
+
+  def check_lock
+    if self.locked?
+      errors.add(:locks, "Sorry, the post is locked by #{self.lock.user.email}") if self.locked? && self.lock.user != @user
+    end
+  end
+end

app/models/user.rb

@@ -4,4 +4,5 @@ class User < ActiveRecord::Base
          :token_authenticatable
 
   attr_accessible :email, :password, :password_confirmation
+  has_many :locks
 end

app/views/posts/_form.html.erb

@@ -0,0 +1,25 @@
+<%= form_for(@post) do |f| %>
+  <% if @post.errors.any? %>
+    <div id="error_explanation">
+      <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2>
+
+      <ul>
+      <% @post.errors.full_messages.each do |msg| %>
+        <li><%= msg %></li>
+      <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div class="field">
+    <%= f.label :title %><br />
+    <%= f.text_field :title %>
+  </div>
+  <div class="field">
+    <%= f.label :body %><br />
+    <%= f.text_field :body %>
+  </div>
+  <div class="actions">
+    <%= f.submit %>
+  </div>
+<% end %>

app/views/posts/edit.html.erb

@@ -0,0 +1,6 @@
+<h1>Editing post</h1>
+
+<%= render 'form' %>
+
+<%= link_to 'Show', @post %> |
+<%= link_to 'Back', posts_path %>

app/views/posts/index.html.erb

@@ -0,0 +1,25 @@
+<h1>Listing posts</h1>
+
+<table>
+  <tr>
+    <th>Title</th>
+    <th>Body</th>
+    <th></th>
+    <th></th>
+    <th></th>
+  </tr>
+
+<% @posts.each do |post| %>
+  <tr>
+    <td><%= post.title %></td>
+    <td><%= post.body %></td>
+    <td><%= link_to 'Show', post %></td>
+    <td><%= link_to 'Edit', edit_post_path(post) %></td>
+    <td><%= link_to 'Destroy', post, :confirm => 'Are you sure?', :method => :delete %></td>
+  </tr>
+<% end %>
+</table>
+
+<br />
+
+<%= link_to 'New Post', new_post_path %>

app/views/posts/new.html.erb

@@ -0,0 +1,5 @@
+<h1>New post</h1>
+
+<%= render 'form' %>
+
+<%= link_to 'Back', posts_path %>

app/views/posts/show.html.erb

@@ -0,0 +1,15 @@
+<p id="notice"><%= notice %></p>
+
+<p>
+  <b>Title:</b>
+  <%= @post.title %>
+</p>
+
+<p>
+  <b>Body:</b>
+  <%= @post.body %>
+</p>
+
+
+<%= link_to 'Edit', edit_post_path(@post) %> |
+<%= link_to 'Back', posts_path %>

config/routes.rb

@@ -1,10 +1,14 @@
 DeviseExample::Application.routes.draw do
+  resources :locks
+
+  resources :posts
+
   devise_for :users, :admin
 
   resources :home, :only => :index
   resources :admins, :only => :index
 
-  root :to => 'home#index'
+  root :to => 'posts#index'
 
   match '/token' => 'home#token', :as => :token
 end

db/migrate/20111013044839_create_posts.rb

@@ -0,0 +1,14 @@
+class CreatePosts < ActiveRecord::Migration
+  def self.up
+    create_table :posts do |t|
+      t.string :title
+      t.string :body
+
+      t.timestamps
+    end
+  end
+
+  def self.down
+    drop_table :posts
+  end
+end

db/migrate/20111013045407_create_locks.rb

@@ -0,0 +1,15 @@
+class CreateLocks < ActiveRecord::Migration
+  def self.up
+    create_table :locks do |t|
+      t.integer :user_id
+      t.integer :lockable_id
+      t.string :lockable_type
+
+      t.timestamps
+    end
+  end
+
+  def self.down
+    drop_table :locks
+  end
+end

db/schema.rb

@@ -1,3 +1,4 @@
+# encoding: UTF-8
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -10,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20100615195947) do
+ActiveRecord::Schema.define(:version => 20111013045407) do
 
   create_table "admins", :force => true do |t|
     t.string   "email",                             :default => "", :null => false
@@ -19,21 +20,36 @@
     t.datetime "updated_at"
   end
 
+  create_table "locks", :force => true do |t|
+    t.integer  "user_id"
+    t.integer  "lockable_id"
+    t.string   "lockable_type"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  create_table "posts", :force => true do |t|
+    t.string   "title"
+    t.string   "body"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
   create_table "users", :force => true do |t|
-    t.string   "email",                               :default => "", :null => false
-    t.string   "encrypted_password",   :limit => 128, :default => "", :null => false
+    t.string   "email",                                 :default => "", :null => false
+    t.string   "encrypted_password",     :limit => 128, :default => "", :null => false
     t.string   "confirmation_token"
     t.datetime "confirmed_at"
     t.datetime "confirmation_sent_at"
     t.string   "reset_password_token"
-    t.string   "remember_token"
+    t.datetime "reset_password_sent_at"
     t.datetime "remember_created_at"
-    t.integer  "sign_in_count",                       :default => 0
+    t.integer  "sign_in_count",                         :default => 0
     t.datetime "current_sign_in_at"
     t.datetime "last_sign_in_at"
     t.string   "current_sign_in_ip"
     t.string   "last_sign_in_ip"
-    t.integer  "failed_attempts",                     :default => 0
+    t.integer  "failed_attempts",                       :default => 0
     t.string   "unlock_token"
     t.datetime "locked_at"
     t.datetime "created_at"

public/stylesheets/scaffold.css

@@ -0,0 +1,56 @@
+body { background-color: #fff; color: #333; }
+
+body, p, ol, ul, td {
+  font-family: verdana, arial, helvetica, sans-serif;
+  font-size:   13px;
+  line-height: 18px;
+}
+
+pre {
+  background-color: #eee;
+  padding: 10px;
+  font-size: 11px;
+}
+
+a { color: #000; }
+a:visited { color: #666; }
+a:hover { color: #fff; background-color:#000; }
+
+div.field, div.actions {
+  margin-bottom: 10px;
+}
+
+#notice {
+  color: green;
+}
+
+.field_with_errors {
+  padding: 2px;
+  background-color: red;
+  display: table;
+}
+
+#error_explanation {
+  width: 450px;
+  border: 2px solid red;
+  padding: 7px;
+  padding-bottom: 0;
+  margin-bottom: 20px;
+  background-color: #f0f0f0;
+}
+
+#error_explanation h2 {
+  text-align: left;
+  font-weight: bold;
+  padding: 5px 5px 5px 15px;
+  font-size: 12px;
+  margin: -7px;
+  margin-bottom: 0px;
+  background-color: #c00;
+  color: #fff;
+}
+
+#error_explanation ul li {
+  font-size: 12px;
+  list-style: square;
+}