callback-example.rb

# =====================================================================================================
# Template for generating a callback example
# =====================================================================================================

# Requirements:
# -------------
#
# * Ruby  >= 1.9.3
# * Rails >= 4

# Usage:
# ------
#
#     $ rails new callback-example --skip-bundle --template callback-example.rb
#
# =====================================================================================================

# ----- Use Thin ----------------------------------------------------------------------------------

begin
  require 'thin'
  gem 'thin'
rescue LoadError
end

# ----- Remove CoffeeScript, Sass and "all that jazz" ---------------------------------------------

comment_lines 'Gemfile', /gem 'coffee/
comment_lines 'Gemfile', /gem 'sass/
comment_lines 'Gemfile', /gem 'uglifier/
uncomment_lines 'Gemfile', /gem 'therubyracer/

# ----- Disable asset logging in development ------------------------------------------------------

environment 'config.assets.logger = false', env: 'development'
gem 'quiet_assets',  group: "development"

# ----- Install gems ------------------------------------------------------------------------------

run "bundle install"

# ----- Generate a resource to test around_update callback  -------------------------------------------------------

generate :scaffold, "post name:string user:belongs_to"
generate :scaffold, "user name:string"
generate :scaffold, "profile name:string user:belongs_to"
route "root to: 'posts#index'"
rake "db:migrate"

# ----- Add Associations -------------------

run "rm -f app/models/user.rb"
file 'app/models/user.rb', <<-CODE
class User < ActiveRecord::Base
  has_one :profile

  has_many :posts
end
CODE

# ----- Add Callback -------------------

run "rm -f app/models/profile.rb"
file 'app/models/profile.rb', <<-CODE
class Profile < ActiveRecord::Base
  belongs_to :user

  around_update :test_method

  private
  def test_method
    print "beforeZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ"
    yield
    print "afterZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ"
  end
end
CODE

# ----- Add #duplicate_post to post model -------------------

run "rm -f app/models/post.rb"
file 'app/models/post.rb', <<-CODE
class Post < ActiveRecord::Base
  belongs_to :user

  def duplicate_post
    duplicate = self.dup
    duplicate.save(:validate => false)

    return duplicate
  end
end
CODE

# ----- Add #duplicate_post to post model -------------------

run "rm -f app/controllers/posts_controller.rb"
file 'app/controllers/posts_controller.rb', <<-'CODE'
class PostsController < ApplicationController
  before_action :set_post, only: [:show, :edit, :update, :destroy, :duplicate]

  # GET /posts
  # GET /posts.json
  def index
    @posts = Post.all
  end

  # GET /posts/1
  # GET /posts/1.json
  def show
  end

  # GET /posts/new
  def new
    @post = Post.new
  end

  # GET /posts/1/edit
  def edit
  end

  # POST /posts
  # POST /posts.json
  def create
    @post = Post.new(post_params)

    respond_to do |format|
      if @post.save
        format.html { redirect_to @post, notice: 'Post was successfully created.' }
        format.json { render :show, status: :created, location: @post }
      else
        format.html { render :new }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /posts/1
  # PATCH/PUT /posts/1.json
  def update
    respond_to do |format|
      if @post.update(post_params)
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { render :show, status: :ok, location: @post }
      else
        format.html { render :edit }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /posts/1
  # DELETE /posts/1.json
  def destroy
    @post.destroy
    respond_to do |format|
      format.html { redirect_to posts_url, notice: 'Post was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  def duplicate
    duplicate_post = @post.duplicate_post
    
    if duplicate_post.save(:validate => false)
      redirect_to post_url(duplicate_post)
    else
      raise RuntimeError, "failed: #{duplicate_post.errors}"
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_post
      @post = Post.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def post_params
      params.require(:post).permit(:name, :user_id)
    end
end
CODE

# ----- Add Tests -------------------

run "rm -f test/models/profile_test.rb"
file 'test/models/profile_test.rb', <<-CODE
require 'test_helper'

class ProfileTest < ActiveSupport::TestCase
  test "updates trigger around_update callback #test_method" do
    assert true
  end
end
CODE

run "rm -f test/models/post_test.rb"
file 'test/models/post_test.rb', <<-CODE
require 'test_helper'

class PostTest < ActiveSupport::TestCase
   test "#duplicate_post should not trigger Profile's around_update callback #test_method" do
     assert true
   end
end
CODE