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Week-06-Nested-Controllers-Forms-And-Validations.md

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Week-06-Nested-Controllers-Forms-And-Validations.md

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Week 6 - Nested Controllers, Forms and Validations

Nested Resources (continued)

New Reviews

  1. Add a new review link on app/views/reviews/show.html.erb

    <h1><%= @book.name %></h1>

<%= link_to "Edit", edit_book_path(@book) %> |
<%= link_to "Delete", @book, method: :delete, data:{confirm: "Are you sure?"} %>
<p>Pages: <%= @book.pages %></p>
<p><%= simple_format @book.summary %></p>

<h2>Reviews</h2>

<!-- Add this line --->
<%= link_to "Add Review", new_book_review_path(@book) %>

<% @reviews.each do |review| %>
<div>
  <%= simple_format review.body %>
  <%= link_to [@book, review] do %>
    <p style="font-style: italic"><%= review.name %> gave this book a <%= review.rating %> star rating.</p>
  <% end %>
</div>
<% end %>

<%= link_to "All Books", books_path %>

  2. Add the new route in config/routes.rb

    Bookstore::Application.routes.draw do
  resources :books do
    resources :reviews, only: [:show, :new]
  end
end

  3. Create the new action in app/controllers/reviews_controller.rb

    class ReviewsController < ApplicationController
  def show
    @book = Book.find params[:book_id]
    @review = @book.reviews.find params[:id]
  end

  def new
    @book = Book.find params[:book_id]
    @review = @book.reviews.new
  end
end

  4. Create app/views/reviews/new.html.erb

    <%= form_for [@book, @review] do |f| %>
  <div>
    <%= f.label :name %>
    <%= f.text_field :name %>
  </div>
  <div>
    <%= f.label :rating %>
    <%= f.text_field :rating %>
  </div>
  <div>
    <%= f.label :body %>
    <%= f.text_area :body %>
  </div>

  <%= f.submit %>
<% end %>

  5. Add create route in config/routes.rb

    Bookstore::Application.routes.draw do
  resources :books do
    resources :reviews, only: [:show, :new, :create]
  end
end

  6. Add the create action to app/controllers/reviews_controller.rb

    class ReviewsController < ApplicationController
  def show
    @book = Book.find params[:book_id]
    @review = @book.reviews.find params[:id]
  end

  def new
    @book = Book.find params[:book_id]
    @review = @book.reviews.new
  end

  def create
    @book = Book.find params[:book_id]
    @review = @book.reviews.new params[:review]
    @review.save
    redirect_to [@book, @review]
  end
end

  7. Commit

    git add .
git commit -m "New review functionality"

  8. Refactor app_controllers/reviews_controller.rb to use a before_filter

    class ReviewsController < ApplicationController
  before_filter :find_book

  def show
    @review = @book.reviews.find params[:id]
  end

  def new
    @review = @book.reviews.new
  end

  def create
    @review = @book.reviews.create params[:book]
    @review.save
    redirect_to [@book, @review]
  end

  private

  def find_book
    @book = Book.find params[:book_id]
  end
end

  9. Commit

    git add .
git commit -m "Extract book loading to before filter"

Editing Reviews

  1. Create an edit link in app/views/reviews/show.html.erb

    <h1>Review #<%= @review.id %> for <%= link_to @book.name, @book %></h1>

<p><%= @review.name %> gave this book <%= @review.rating %> stars</p>

<%= simple_format @review.body %>

<%= link_to "Edit", edit_book_review_path(@book, @review) %>

  2. Add edit route to config/routes.rb

    Bookstore::Application.routes.draw do
  resources :books do
    resources :reviews, only: [:show, :new, :create, :edit]
  end
end

  3. Add edit action to app/controllers/reviews_controller.rb

    def edit
  @review = @book.reviews.find params[:id]
end

  4. Add app/views/edit.html.erb

    <%= render "form" %>

  5. Move contents of app/views/reviews/new.html into app/views/reviews/_form.html.erb

    <%= form_for [@book, @review] do |f| %>
  <div>
    <%= f.label :name %>
    <%= f.text_field :name %>
  </div>
  <div>
    <%= f.label :rating %>
    <%= f.text_field :rating %>
  </div>
  <div>
    <%= f.label :body %>
    <%= f.text_area :body %>
  </div>

  <%= f.submit %>
<% end %>

  6. Edit app/views/new.html.erb

    <%= render "form" %>

  7. Create update route in config/routes.rb

    Bookstore::Application.routes.draw do
  resources :books do
    resources :reviews, only: [:show, :new, :create, :edit, :update]
  end
end

  8. Create update action in app/controllers/reviews_controller.rb

    def update
  @review = @book.reviews.find params[:id]
  @review.update_attributes params[:review]
  redirect_to [@book, @review]
end

  9. Commit

    git add .
git commit -m "Edit reviews"

Deleting a review

  1. Add a delete link to app/views/reviews/show.html.erb

    <h1>Review #<%= @review.id %> for <%= link_to @book.name, @book %></h1>

<p><%= @review.name %> gave this book <%= @review.rating %> stars</p>

<%= simple_format @review.body %>

<%= link_to "Edit", edit_book_review_path(@book, @review) %> |
<%= link_to "Delete", book_review_path(@book, @review), method: :delete, data: {confirm: "Are you sure?"} %>

  2. Add the destroy route to config/routes.rb

    Bookstore::Application.routes.draw do
  resources :books do
    resources :reviews, only: [:show, :new, :create, :edit, :update, :destroy]
  end
end

  3. Add the destroy action to app/controllers/reviews_controller.rb

    def destroy
  @review = @book.reviews.find params[:id]
  @review.destroy
  redirect_to @book
end

  4. Commit

    git add .
git commit -m "Delete reviews"

Validations

  1. Require book name is set. In app/models/book.rb

    class Book < ActiveRecord::Base
  has_many :reviews
  attr_accessible :name, :pages, :summary

  validates_presence_of :name
end

  2. Try to create new book without a title in the console

    $ rails c
Loading development environment (Rails 3.2.17)
2.0.0-p247 :001 > book = Book.new
 => #<Book id: nil, name: nil, pages: nil, created_at: nil, updated_at: nil, summary: nil>
2.0.0-p247 :002 > book.save
   (0.1ms)  begin transaction
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = f
alse to avoid this message.
   (0.1ms)  rollback transaction
 => false
2.0.0-p247 :003 > book.errors.full_messages
 => ["Name can't be blank"]
2.0.0-p247 :004 > book.name = "War and Peace"
 => "War and Peace"
2.0.0-p247 :005 > book.valid?
 => true
2.0.0-p247 :006 > book.save
   (0.1ms)  begin transaction
  SQL (4.9ms)  INSERT INTO "books" ("created_at", "name", "pages", "summary", "updated_at") VALUES (?, ?, ?, ?, ?)  [["created_at", Mon, 17 Mar 2014 00:46:12 UTC +00:00], ["name",
 "War and Peace"], ["pages", nil], ["summary", nil], ["updated_at", Mon, 17 Mar 2014 00:46:12 UTC +00:00]]
   (30.5ms)  commit transaction
 => true
2.0.0-p247 :007 >

  3. Update app/controllers/books_controller.rb to re-display the form if the create action fails

    def create
  @book = Book.new params[:book]
  if @book.save
    redirect_to @book
  else
    render 'new'
  end
end
    def update
  @book = Book.find params[:id]
  if @book.update_attributes params[:book]
    redirect_to @book
  else
    render "edit"
  end
end

  4. Show the errors on the book form (app/views/books/_form.html.erb)

    <%= form_for @book do |f| %>
  <% if @book.errors.any? %>
  <div class="errors">
    The form contains <%= pluralize(@book.errors.count, "error") %>.
     <ul>
    <% @book.errors.full_messages.each do |msg| %>
      <li> <%= msg %></li>
    <% end %>
    </ul>
  </div>
  <% end %>
  <div>
    <%= f.label :name %>
    <%= f.text_field :name %>
  </div>
  <div>
    <%= f.label :pages %>
    <%= f.text_field :pages %>
  </div>
  <div>
    <%= f.label :summary %>
    <%= f.text_area :summary %>
  </div>
  <%= f.submit %>
<% end %>

  5. Ensure pages greater than 0. (app/models/book.rb)

    class Book < ActiveRecord::Base
  has_many :reviews
  attr_accessible :name, :pages, :summary

  validates_presence_of :name
  validates_numericality_of :pages, greater_than: 0, allow_blank: true
end

  6. Commit

    git add .
git commit -m "Added book validations"

Inline error messages and form builder

  1. Add simple_form to the Gemfile.

    gem 'simple_form', '~> 2.1.1'

  2. Install gem

    bundle install

  3. Run simple form install generator

    rails generate simple_form:install

  4. Update app/views/books/_form.html.erb

    <%= simple_form_for @book do |f| %>
  <%= f.input :name %>
  <%= f.input :pages %>
  <%= f.input :summary %>

  <%= f.submit %>
<% end %>

  5. Commit

    git add .
git commit -m "Added simple form"

Adding bootstrap

  1. Add the bootstrap-sass gem to the Gemfile (in the assets group)

    gem 'bootstrap-sass', '~> 2.1.1.0'

  2. Bundle install

    bundle install

  3. Rename app/assets/stylesheets/application.css to app/assets/stylesheets/application.css.scss

    git mv app/assets/stylesheets/application.css app/assets/stylesheets/application.css.scss

  4. Import bootstrap in app/assets/stylesheets/application.css.scss

    @import "bootstrap";

  5. Reinstall simple form with bootstrap support

    rails generate simple_form:install --bootstrap

  6. Style the form buttons app/views/books/_form.html.erb

    <%= simple_form_for @book do |f| %>
  <%= f.input :name %>
  <%= f.input :pages %>
  <%= f.input :summary %>

  <%= f.submit class: "btn btn-primary" %>
<% end %>

  7. Commit

    git add .
git commit -m "Added bootstrap"

Review validations

  1. Update app/controllers/reviews_controller.rb to handle invalid data

    def create
  @review = @book.reviews.new params[:review]
  if @review.save
    redirect_to [@book, @review]
  else
    render "new"
  end
end
    def update
  @review = @book.reviews.find params[:id]
  if @review.update_attributes params[:review]
    redirect_to [@book, @review]
  else
    render "edit"
  end
end

  2. Make review name, rating, and body required (app/models/review.rb)

    class Review < ActiveRecord::Base
  belongs_to :book
  attr_accessible :body, :name, :rating

  validates_presence_of :name, :rating, :body
end

  3. Convert app/views/reviews/_form.html.erb to use simple form

    <%= simple_form_for [@book, @review] do |f| %>
  <%= f.input :name %>
  <%= f.input :rating %>
  <%= f.input :body %>

  <%= f.submit, class: "btn btn-primary"%>
<% end %>

  4. Commit

    git add .
git commit -m "Reviews simple form and validations"

Rating as a dropdown

  1. Update review model to only allow ratings as integers between 1 and 5

    class Review < ActiveRecord::Base
  belongs_to :book
  attr_accessible :body, :name, :rating

  validates_presence_of :name, :rating, :body
  validates_numericality_of :rating, only_integer: true, greater_than_or_equal_to: 1, less_than_or_equal_to: 5
end

  2. Update review form to render ratings as a select menu

    <%= simple_form_for [@book, @review] do |f| %>
  <%= f.input :name %>
  <%= f.input :rating, as: :select, collection: 1..5 %>
  <%= f.input :body %>

  <%= f.submit, class: "btn btn-primary" %>
<% end %>

  3. Commit

    git add .
git commit -m "Rating is now a dropdown"

Destroy related reviews when deleting books

  1. Update app/views/book.rb
class Book < ActiveRecord::Base
  has_many :reviews, dependent: :destroy
  attr_accessible :name, :pages, :summary

  validates_presence_of :name
  validates_numericality_of :pages, greater_than: 0, allow_blank: true
end