rails 开发

July 30, 2018

• 参考
  • Ruby on Rails Guides (v4.2.10)
  • Active Record 基础

i18n 资源

在 config/locales/en.yml 定义

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label_xc_tags_title: 'Tags'

在任何view中都可以使用，例如：

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<legend><%= l(:label_xc_tags_title)%></legend>

model

• 参考
  • ruby-china - Active Record 基础

设置多对多关系

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# FILE: app/models/issue.rb
has_and_belongs_to_many :xc_tags, :join_table => :xc_tags_issues

# FILE: app/models/xc_tag.rb
has_and_belongs_to_many :issues, :join_table => :xc_tags_issues

view

跨controller，跨格式，引用view

• 跨controller ： render(:partial => 'another-controller/its-partial-view')
• 跨格式 ： render(..., :local => {:format => 'html'})

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# app/views/xc_tags/tagissue.js.erb

<%# 更新issue备注（历史记录） %>
<% htmlstr = "<h3>#{l(:label_history)}</h3>" %>
<% htmlstr += render(:partial => 'issues/history', :locals => {:format => 'html', :issue => @issue, :journals => @issue.journals }) %>
<% htmlstr.gsub!('"', '\\"') %>
<% htmlstr.gsub!("\n", ' ') %>
$("#history").html("<%= htmlstr.html_safe %>");

routes

• 参考
  • https://guides.rubyonrails.org/v4.2/routing.html

默认 route 和 helper 简单的例子

resources :photos

• path helpers：

  • photos_path returns /photos
  • new_photo_path returns /photos/new
  • edit_photo_path(:id) returns /photos/:id/edit (如，edit_photo_path(10) returns /photos/10/edit)
  • photo_path(:id) returns /photos/:id (如， photo_path(10) returns /photos/10)

• url helpers:
  把 path helpers 函数名中path替换为url就行了，例如，photos_url ，就是比 photos_path 多了 协议和host的前缀，如，http://your-host/photos

嵌入式的route / Nested Resources

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class Magazine < ActiveRecord::Base
  has_many :ads
end
 
class Ad < ActiveRecord::Base
  belongs_to :magazine
end

• route 规则

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resources :magazines do
  resources :ads
end

命令行列出所有可用routes

在 config/route.rb 中配置 route

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bundle exec rake routes

# 某个controller 的 routes
CONTROLLER=users bundle exec rake routes

helper 生成 path url

route.rb 中： get '/patients/:id', to: 'patients#show', as: 'patient'

controller 中： @patient = Patient.find(17)

view 中 <%= link_to 'Patient Record', patient_path(@patient) %> 会生成链接指向 /patients/17

默认 route 规则

route.rb 中规则从上到下匹配，先匹配先生效。

GET /patients/17 匹配 get '/patients/:id', to: 'patients#show'

• resources :objects

一句route 配置规则，就能覆盖 index, show, new, edit, create, update and destroy actions。

开发模式直接网页查看 routes

http://localhost:3000/rails/info/routes

命令行工具

• rubyonrails.org - The Rails Command Line

自动生成CRUD

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# 会同时生成：db的migraton脚本、model、contorller、view代码
bundle exec rails generate scaffold XcJtag name:string color:string

生成 controller

• 语法

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bin/rails generate controller NAME [action action] [options]

• 例子

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bin/rails generate controller CreditCards open debit credit close

database migration

• ruby-china - Active Record 迁移

简单的例子

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class CreateXcJtags < ActiveRecord::Migration
  def up
    create_table :xc_jtags do |t|
      t.string :name
      t.string :color  # css style 语法

      t.timestamps null: false
    end

    create_join_table :journals, :xc_jtags, :table_name => :xc_jtags_journals

    XcJtag.create(name:"自动QA", color:"color:white; background-color:greenyellow;")
  end

  def down
    drop_table :xc_jtags
    drop_table :xc_jtags_journals
  end
end

执行 migration

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bundle exec rake db:migrate

# migrate 到指定版本
bundle exec rake db:migrate VERSION=20080906120000

回滚 migration

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# 回退一个migration
bundle exec rake db:rollback

# 回退 3个migration
bundle exec rake db:rollback STEP=3