Girls_I_Loved
a comprehensive Rails 3.2 CRUD example
001 Rails
Rails Rails
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DRY DIY
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Convention Over Configuration
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REST HTTP
MVCMVC Model View Controller
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--
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MVC ** HTML PHP ** 200 OGC 90...
Rails ...
Rails
RVMRVM Ruby Ruby Ruby Gems RVM RVM Gemset
Rails 3.2.3 Ruby 1.9.3
rvm install 1.9.3 (rvm use --default 1.9.3 )
Ruby 1.9.2+ RubyGemsMac/Unix Rails
gem install rails -v 3.2.3
...
** Rails**
Rails Gems Gem Gem Rails Gem Ruby bundle building native ... GFW RubyGems
...
Rails
Rails
girls_I_loved
rails
rails new girls_I_loved
DONT PANIC Rails
** rails help rails
cd girls_I_loved
([path-to-your-app/girls_I_loved] $)
rails server Ruby WEBrick
http://0.0.0.0:3000/ http://localhost:3000/ http://127.0.0.1:3000/
Rails Ruby
About your applications environment Rails
Environment development
Rails development, test, production development cached
sqlite3
Database adapter sqlite3
** ctrl + C rails s rails server
Rails
scaffold Rails Rails craftman
``
rails generate scaffold girl name:string number:integer
girl name:string number:integer
girl name number
attribute Rails Migration
Rails schemaTimestamp
db/migrate/[YYYYMMDDHHMMSS]_create_girls.rb
db/migrate/
class CreateGirls < ActiveRecord::Migration
def change
create_table :girls do |t|
t.string :name
t.integer :number
t.timestamps
end
end
end
ActiveRecord::Migration change
create_table :girls do |t|
girls t.timestamps created_at updated_at Rails rollback change up down
OK! rake db:migrate
== CreateGirls: migrating ====================================================
-- create_table(:girls)
-> 0.0021s
== CreateGirls: migrated (0.0022s) ===========================================
rake db:migrate up Rails db/development.sqlite3 girls rake db:migrate
Rails db/schema.rb
ActiveRecord::Schema.define(:version => YYYYMMDDHHMMSS) do
create_table "girls", :force => true do |t|
t.string "name"
t.integer "number"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
end
YYYYMMDDHHMMSS
db/migrate/[YYYYMMDDHHMMSS]_create_girls.rb
rake db:schema:load
** rake db:rollback down
rails s http://localhost:3000/girls/
New Girl
GirlsController new action
app/views/girls/new.html.erb
<h1>New girl</h1>
<%= render 'form' %>
<%= link_to 'Back', girls_path %>
ERB ERB Embedded RuBy Ruby HTML
<%= %> <% %>
<% hot=true %>
... ERB
h1 render 'form' render render partial
partial partial DRY
link_to a Back href girls_path /girls
_form.html.erb
<%= form_for(@girl) do |f| %>
...
<% end %>
form_for helperform_for @gril @girl
GirlsController new
def new
@girl = Girl.new
respond_to do |format|
format.html # new.html.erb
format.json { render json: @girl }
end
end
Girl new @girl @girl Rails
respond_to HTML JSON format.html new.html.erb format.json @girl JSON
rails generate scaffold girl name:string number:integer
_form.html.erb <%= form_for(@girl) do |f| %> <% end %>
<% if @girl.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(@girl.errors.count, "error") %> prohibited this girl from being saved:</h2>
<ul>
<% @girl.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
@girl @girl validation if
_form.html.erb
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :number %><br />
<%= f.number_field :number %>
</div>
<div class="actions">
<%= f.submit %>
</div>
D
submit create
def create
@girl = Girl.new(params[:girl])
respond_to do |format|
if @girl.save
format.html { redirect_to @girl, notice: 'Girl was successfully created.' }
format.json { render json: @girl, status: :created, location: @girl }
else
format.html { render action: "new" }
format.json { render json: @girl.errors, status: :unprocessable_entity }
end
end
end
new Girl.new params[:girl] params parameters (hash) params[:girl] new Rails
respond_to if-else if @girl.save record
redirect_to @girl redirect_to @girl girl_path Girl show notice: flash flash request
not valid@girl.save nil false render new new new Ruby-china
(validation) @girl
Girl app/models/girl.rb
class Girl < ActiveRecord::Base
attr_accessible :name, :number
validates :name, :presence => true
validates :number, :presence => true,
:uniqueness => true,
:numericality => { :greater_than => 1 }
end
validates http://localhost:3000/girls New Girl Create Girl
name"#{}"
NameError: undefined local variable or method `' for main:Object
greater_than -1
It works!
2 **1 **
N Girl ID show app/views/girls/show.html.erb
<p id="notice"><%= notice %></p>
<p>
<b>Name:</b>
<%= @girl.name %>
</p>
<p>
<b>Number:</b>
<%= @girl.number %>
</p>
<%= link_to 'Edit', edit_girl_path(@girl) %> |
<%= link_to 'Back', girls_path %>
notice create redirec_to notice
format.html { redirect_to @girl, notice: 'Girl was successfully created.' }
p @girl name number show
def show
@girl = Girl.find(params[:id])
...
end
Girl find ID params[:id] record Girl params[:id] N
show.html.erb
<%= link_to 'Edit', edit_girl_path(@girl) %> |
<%= link_to 'Back', girls_path %>
Edit Back link_to edit_girl_path(@girl) config/routes.rb config/routes.rb
Rails
config/routes.rb
GirlsILoved::Application.routes.draw do
resources :girls
end
Rails config/routes.rb Ruby
resources :girls
Rails resourcesroutes helpers helper edit_girl_path helper
:id ID helper girls_path girls_url http://localhost:3000/girls
request GET /girls GirlsController index GET http://localhost:3000/ /girls POST create New Girl http://localhost:3000/girls/new ->
<form accept-charset="UTF-8" action="/girls" class="new_girl" id="new_girl" method="post">
action method action method HTTP
app/views/girls/new.html.erb
<h1>New girl</h1>
<%= render 'form' %>
<%= link_to 'Back', girls_path %>
partial app/views/girls/_form.html.erb form
<%= form_for(@girl) do |f| %>
form edit
/girls/{id} GET show update
http://localhost:3000/girls Edit
new partial edit.html.erb
<h1>Editing girl</h1>
<%= render 'form' %>
<%= link_to 'Show', @girl %> |
<%= link_to 'Back', girls_path %>
new GirlsController edit
def edit
@girl = Girl.find(params[:id])
end
show action
edit.html.erb
<h1>Editing girl</h1>
<%= render 'form' %>
<%= link_to 'Show', @girl %> |
<%= link_to 'Back', girls_path %>
link_to Show Back Show edit @girl girl_path(@girl) (/girls/:id)Rails Rails girl_path Girl
Back girls_path girls_path index
Update Girl
Update Girl show Back ( http://localhost:3000/2/edit/)
<form accept-charset="UTF-8" action="/girls/2" class="edit_girl" id="edit_girl_2" method="post"
<div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="✓" /><input name="_method" type="hidden" value="put" />...
</div>
action /girls/2 GirlsController show method POST _method input value PUTRails POST PUT /girls/{id} PUT GirlsController update update
def update
@girl = Girl.find(params[:id])
respond_to do |format|
if @girl.update_attributes(params[:girl])
format.html { redirect_to @girl, notice: 'Girl was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: "edit" }
format.json { render json: @girl.errors, status: :unprocessable_entity }
end
end
end
show edit find create params[:girl] update_attributes
update_attributes show edit create edit
def create
...
else
format.html { render action: "new" }
format.json { render json: @girl.errors, status: :unprocessable_entity }
end
...
RailsDELETE DESTROY DESTROY
Destroy
app/views/girls/index.html.erb
<h1>Listing girls</h1>
...
<% @girls.each do |girl| %>
<tr>
<td><%= girl.name %></td>
<td><%= girl.number %></td>
<td><%= link_to 'Show', girl %></td>
<td><%= link_to 'Edit', edit_girl_path(girl) %></td>
<td><%= link_to 'Destroy', girl, confirm: 'Are you sure?', method: :delete %></td>
</tr>
<% end %>
</table>
<br />
<%= link_to 'New Girl', new_girl_path %>
@girls Girl |girl| girl
name number app/views/girls/show.html.erb Show, Edit, Destroy
girl /girls/{id} GirlsController show {id} ID
edit_girl_path girl edit helper /girls/{id}/edit
girl :delete /girls/{id} method: :delete Rails GirlsController destroy
def destroy
@girl = Girl.find(params[:id])
@girl.destroy
respond_to do |format|
format.html { redirect_to girls_url }
format.json { head :no_content }
end
end
show , edit , update @girl Girl.find(params[:id]
@girl.destroy
girls_url http://localhost:3000/girls girls_url path url URL
Rails
Rails 970
Rails Routing from the Outside In
