Getting started with Rails (3), Season 2

Getting Started with Rails (3)

- The 3rd Round -

July 21, 2012

Hyoseong ChoiROR Lab.

ROR Lab. Season 2

ROR Lab.

A Blog Project

Post

Comment Tag

one to manyone t

o man

y

nested formseparate form

fields_for

form_for

form_for

ROR Lab.

Addinga Second Model

Comment

Class

singularcomments

plural

Database

ORM

ROR Lab.

Addinga Second Model

Comment

Model Class

comments

Database Table

ActiveRecord

object recordattributes fields

ROR Lab.

Generating a Model

$ rails generate model Comment commenter:string body:text post:references

generate scaffoldgenerate modelgenerate controllergenerate migration

ROR Lab.

Generating a Model

$ rails generate model Comment commenter:string body:text

Comment

post:references

belongs_to :post post_id :integer

Comments

Model Class : app/models/comment.rb

Migration file : db/migrate/xxxx_create_comment.rb

ROR Lab.

Generating a Model

class Comment < ActiveRecord::Base belongs_to :postend

class CreateComments < ActiveRecord::Migration def change create_table :comments do |t| t.string :commenter t.text :body t.references :post t.timestamps end add_index :comments, :post_id endend

Model class file

Migration file

$ rake db:migrate

@comment.post

ROR Lab.

Associating Models

Post Comment

Parent Model Child Model

has_many

belongs_to

app/models/post.rb app/models/comment.rb

Relation

ROR Lab.

Associating Models

class Post < ActiveRecord::Base attr_accessible :content, :name, :title validates :name, :presence => true validates :title, :presence => true, :length => { :minimum => 5 } has_many :commentsend

app/models/post.rb

Automatic behavior :

@post.comments

ROR Lab.

Adding a Route

resources :posts do resources :commentsend

config/routes.rb

ROR Lab.

Generating a Controller

$ rails generate controller Comments

ROR Lab.

<p id="notice"><%= notice %></p> <p> <b>Name:</b> <%= @post.name %></p> <p> <b>Title:</b> <%= @post.title %></p> <p> <b>Content:</b> <%= @post.content %></p> <h2>Add a comment:</h2><%= form_for([@post, @post.comments.build]) do |f| %> <div class="field"> <%= f.label :commenter %><br /> <%= f.text_field :commenter %> </div> <div class="field"> <%= f.label :body %><br /> <%= f.text_area :body %> </div> <div class="actions"> <%= f.submit %> </div><% end %> <%= link_to 'Edit Post', edit_post_path(@post) %> |<%= link_to 'Back to Posts', posts_path %> |

A post

comments:

submit

app/views/posts/show.html.erb

ROR Lab.

Creating a Comment

class CommentsController < ApplicationController def create @post = Post.find(params[:post_id]) @comment = @post.comments.create(params[:comment]) redirect_to post_path(@post) endend

$ rails generate controller Comments create destroy

/app/controllers/comments_controller.rb

ROR Lab.

Creating a Comment

<h2>Comments</h2><% @post.comments.each do |comment| %> <p> <b>Commenter:</b> <%= comment.commenter %> </p> <p> <b>Comment:</b> <%= comment.body %> </p><% end %>

/app/views/posts/show.html.erbA post

comments:

submit

ROR Lab.

Refactoring

• Getting long and awkward

• Using “partials” to clean up

ROR Lab.

Refactoring



comments:

submit

Rendering Partial Collections

ROR Lab.

Refactoring



comments:

submit

_comment.html.erb

app/views/comments/_comment.html.erb


ROR Lab.

Refactoring



comments:

submit



ROR Lab.

Refactoring



comments:

submit


<%= render :partial => “comments/comment” %>


ROR Lab.

Refactoring



comments:

submit


<%= render :partial => “comments/comment” %><%= render @post.comments %>


ROR Lab.

Refactoring



comments:

submit


<%= render :partial => “comments/comment” %><%= render @post.comments %>


local variable,comment

ROR Lab.

Refactoring

<%= form_for([@post, @post.comments.build]) do |f| %> <div class="field"> <%= f.label :commenter %><br /> <%= f.text_field :commenter %> </div> <div class="field"> <%= f.label :body %><br /> <%= f.text_area :body %> </div> <div class="actions"> <%= f.submit %> </div><% end %>


comments:

submit

app/views/comments/_form.html.erb

Rendering a Partial Form

ROR Lab.


A post

comments:

submit


ROR Lab.


A post

comments:

submit


<h2>Comments</h2><% @post.comments.each do |comment| %><%= render “comments/comment” %><% end %>

or

<h2>Comments</h2><%= render @post.comments %>

<h2>Add a comment:</h2><%= render "comments/form" %>

ROR Lab.

Deleting Comments

<p> <b>Commenter:</b> <%= comment.commenter %></p> <p> <b>Comment:</b> <%= comment.body %></p> <p> <%= link_to 'Destroy Comment', [comment.post, comment], :confirm => 'Are you sure?', :method => :delete %></p>


DELETE /posts/:post_id/comments/:id

ROR Lab.

Deleting Comments

<p> <b>Commenter:</b> <%= comment.commenter %></p> <p> <b>Comment:</b> <%= comment.body %></p> <p> <%= link_to 'Destroy Comment', [comment.post, comment], :confirm => 'Are you sure?', :method => :delete %></p>


ROR Lab.

Deleting Comments

post_comments GET /posts/:post_id/comments(.:format) comments#index POST /posts/:post_id/comments(.:format) comments#create new_post_comment GET /posts/:post_id/comments/new(.:format) comments#newedit_post_comment GET /posts/:post_id/comments/:id/edit(.:format) comments#edit post_comment GET /posts/:post_id/comments/:id(.:format) comments#show PUT /posts/:post_id/comments/:id(.:format) comments#update DELETE /posts/:post_id/comments/:id(.:format) comments#destroy posts GET /posts(.:format) posts#index POST /posts(.:format) posts#create new_post GET /posts/new(.:format) posts#new edit_post GET /posts/:id/edit(.:format) posts#edit post GET /posts/:id(.:format) posts#show PUT /posts/:id(.:format) posts#update DELETE /posts/:id(.:format) posts#destroy


$ rake routes

ROR Lab.

Deleting Comments

class CommentsController < ApplicationController def create @post = Post.find(params[:post_id]) @comment = @post.comments.create(params[:comment]) redirect_to post_path(@post) end def destroy @post = Post.find(params[:post_id]) @comment = @post.comments.find(params[:id]) @comment.destroy redirect_to post_path(@post) end end

ROR Lab.

Deleting Assoc. Objects

class Post < ActiveRecord::Base attr_accessible :content, :name, :title validates :name, :presence => true validates :title, :presence => true, :length => { :minimum => 5 } has_many :comments, :dependent => :destroy

app/models/post.rb

ROR Lab.

Deleting Assoc. Objects

class Post < ActiveRecord::Base attr_accessible :content, :name, :title validates :name, :presence => true validates :title, :presence => true, :length => { :minimum => 5 } has_many :comments, :dependent => :destroy

app/models/post.rb

:dependent => :destroy:dependent => :delete:dependent => :nullify

Other options:

ROR Lab.

SecurityA very simple HTTP authentication system

class PostsController < ApplicationController http_basic_authenticate_with :name => "dhh", :password => "secret", :except => [:index, :show] # GET /posts # GET /posts.json def index @posts = Post.all respond_to do |format|

ROR Lab.


class CommentsController < ApplicationController http_basic_authenticate_with :name => "dhh", :password => "secret", :only => :destroy def create @post = Post.find(params[:post_id])

ROR Lab.


ROR Lab.

Live DemoCreating a project ~ First model, Post

ROR Lab.

감사합니다.��

Getting started with Rails (3), Season 2

Education

Transcript of Getting started with Rails (3), Season 2