[fixes #4] add Blog CRUD

refactor controllers
add specs

app/abilities/blogger_ability.rb

@@ -1,6 +1,7 @@
 class BloggerAbility < Ability
   def initialize(user)
     can [:show, :destroy, :update], User, { id: user.id }
+    can [:create, :destroy, :update], Blog, { user_id: user.id }
     super
   end
 end

app/controllers/api/v1/blogs_controller.rb

@@ -0,0 +1,20 @@
+class Api::V1::BlogsController < Api::V1::ResourceController
+  skip_before_action :authenticate_user!, only: [:show, :index]
+
+  before_action :set_blogs, only: :index
+  load_resource only: :show
+
+  with_options only: [:create, :update, :destroy] do
+    load_and_authorize_resource :user
+    load_and_authorize_resource :blog, through: :user, shallow: true
+  end
+
+  private
+    def set_blogs
+      @blogs = Blog.all.includes(:author)
+    end
+
+    def resource_params
+      params.require(:blog).permit(:title, :description)
+    end
+end

app/controllers/api/v1/resource_controller.rb

@@ -0,0 +1,56 @@
+class Api::V1::ResourceController < Api::V1::BaseController
+  def index
+    resources = paginate(self.resources)
+    render json: collection_serializer_klass.new(
+      resources,
+      each_serializer: collection_each_serializer_klass,
+      root: controller_name,
+      meta: meta_attributes(resources)
+    )
+  end
+
+  def show
+    render json: resource
+  end
+
+  def create
+    if resource.save
+      render json: resource, status: :created
+    else
+      render json: resource.errors.full_messages, status: :unprocessable_entity
+    end
+  end
+
+  def update
+    if resource.update(resource_params)
+      render json: resource, status: :ok
+    else
+      render json: resource.errors.full_messages, status: :unprocessable_entity
+    end
+  end
+
+  def destroy
+    if resource.destroy
+      render json: { message: 'resource deleted successfully' }, status: :ok
+    else
+      render json: resource.errors.full_messages, status: :unprocessable_entity
+    end
+  end
+
+  protected
+    def resource
+      instance_variable_get("@#{ controller_name.singularize }")
+    end
+
+    def resources
+      instance_variable_get("@#{ controller_name }")
+    end
+
+    def collection_each_serializer_klass
+      Api::V1.const_get("#{ controller_name.classify }Serializer")
+    end
+
+    def collection_serializer_klass
+      ActiveModel::ArraySerializer
+    end
+end

app/controllers/api/v1/users_controller.rb

@@ -1,45 +1,6 @@
-class Api::V1::UsersController < Api::V1::BaseController
+class Api::V1::UsersController < Api::V1::ResourceController
   load_and_authorize_resource
 
-  def show
-    render json: @user
-  end
-
-  def index
-    users = paginate(User.all)
-    render json: ActiveModel::ArraySerializer.new(
-      users,
-      each_serializer: Api::V1::UserSerializer,
-      root: 'users',
-      meta: meta_attributes(users)
-    )
-  end
-
-  def destroy
-    if @user.destroy
-      render json: { message: 'resource deleted successfully' }, status: :ok
-    else
-      render json: @user.errors.full_messages, status: :unprocessable_entity
-    end
-  end
-
-  def create
-    user = User.new(resource_params)
-    if user.save
-      render json: user, status: :created
-    else
-      render json: user.errors.full_messages, status: :unprocessable_entity
-    end
-  end
-
-  def update
-    if @user.update(resource_params)
-      render json: @user, status: :ok
-    else
-      render json: @user.errors.full_messages, status: :unprocessable_entity
-    end
-  end
-
   private
     def resource_params
       params.require(:user)

app/controllers/concerns/pagination_helpers.rb

@@ -2,6 +2,7 @@ module PaginationHelpers
   extend ActiveSupport::Concern
 
   private
+    # collection must be a pagination object
     def meta_attributes(collection)
       {
         current_page:  collection.current_page,
@@ -13,8 +14,10 @@ def meta_attributes(collection)
     end
 
     def paginate(collection, options = {})
-      collection
-      .page(params[:page] || options[:page])
-      .per_page(params[:per_page] || options[:per_page] || WillPaginate.per_page)
+      require 'will_paginate/array' if collection.is_a?(Array)
+      collection.paginate({
+        page: params[:page] || options[:page],
+        per_page: params[:per_page] || options[:per_page] || WillPaginate.per_page
+      })
     end
 end

app/models/ability.rb

@@ -3,6 +3,7 @@ class Ability
 
   def initialize(user)
     cannot [:index], User
+    can [:show, :index], Blog
   end
 
   def self.for_user(user)

app/models/blog.rb

@@ -0,0 +1,7 @@
+class Blog < ApplicationRecord
+  # Associations
+  belongs_to :author, foreign_key: :user_id, class_name: :User
+
+  # Validations
+  validates :title, :description, presence: true
+end

app/models/user.rb

@@ -6,6 +6,9 @@ class User < ApplicationRecord
   # Enums
   enum role: { guest: 3, blogger: 4, admin: 5 }
 
+  # Associations
+  has_many :blogs, dependent: :destroy
+
   # Validations
   validates :email, :first_name, presence: true
   with_options allow_blank: true do

app/serializers/api/v1/blog_serializer.rb

@@ -0,0 +1,5 @@
+class Api::V1::BlogSerializer < ActiveModel::Serializer
+  attributes :id, :title, :description
+
+  has_one :author, serializer: UserSerializer
+end

config/initializers/active_record_belongs_to_required_by_default.rb

@@ -3,4 +3,8 @@
 # Require `belongs_to` associations by default. This is a new Rails 5.0
 # default, so it is introduced as a configuration option to ensure that apps
 # made on earlier versions of Rails are not affected when upgrading.
-Rails.application.config.active_record.belongs_to_required_by_default = true
+# Rails.application.config.active_record.belongs_to_required_by_default = true
+#
+# [HACK]: `cancancan` gem hinder the loading sequence.
+# see: https://github.com/CanCanCommunity/cancancan/pull/292/files
+ActiveRecord::Base.belongs_to_required_by_default = true

config/initializers/overrides/strong_parameters.rb

@@ -0,0 +1,6 @@
+# https://github.com/rails/rails/pull/22830
+module ActionController
+  class Parameters
+    delegate :include?, to: :@parameters
+  end
+end

config/routes.rb

@@ -1,15 +1,15 @@
 Rails.application.routes.draw do
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
-
-  # Serve websocket cable requests in-process
-  # mount ActionCable.server => '/cable'
-
   namespace :api do
     namespace :v1 do
       controller :sessions do
         post :login, action: :create
       end
-      resources :users, only: [:index, :create, :show, :update, :destroy]
+
+      resources :users, only: [:index, :create, :show, :update, :destroy] do
+        resources :blogs, only: [:create, :show, :update, :destroy], shallow: true
+      end
+      resources :blogs, only: [:index]
     end
   end
 end

db/migrate/20160128192002_create_blogs.rb

@@ -0,0 +1,11 @@
+class CreateBlogs < ActiveRecord::Migration[5.0]
+  def change
+    create_table :blogs do |t|
+      t.references :user, index: true, foreign_key: true
+      t.string :title
+      t.text :description
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -11,7 +11,16 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160128165609) do
+ActiveRecord::Schema.define(version: 20160128192002) do
+
+  create_table "blogs", force: :cascade do |t|
+    t.integer  "user_id"
+    t.string   "title"
+    t.text     "description"
+    t.datetime "created_at",  null: false
+    t.datetime "updated_at",  null: false
+    t.index ["user_id"], name: "index_blogs_on_user_id"
+  end
 
   create_table "users", force: :cascade do |t|
     t.string   "email"