Rails不明记录

Rails中命名路由的区别_url与_path

命名路由

  • path是相对路径
  • url是绝对路径

集合

字符串数组：STATES = %w(draft open closed)等同于STATES = [“draft”, “open”, “closed”] 推荐使用前者

测试 rspec、factory_girl、shoulda-matchers

rails g rspec:model order

gem "faker"
gem "factory_girl_rails", "~> 4.0"
group :development, :test do
  %w[rspec rspec-core rspec-expectations rspec-mocks rspec-rails rspec-support].each do |lib|
    # gem lib, :git => "https://github.com/rspec/#{lib}.git", :branch => 'master'
    gem "#{lib}"
  end
end
group :test do
  gem 'shoulda-matchers', '~> 3.1'
  gem 'capybara' #模拟操作
  gem 'poltergeist'  # capybara phantomjs driver
  gem 'selenium-webdriver' #结合capybara，测试js
  gem 'database_cleaner' #清楚测试数据
  gem 'launchy' #打开浏览器
end

layout

yield :name
content_for :name

约定大于配置（比如：单复数、表之间关系等）

Gem引用

gem 'name', '~ 1.1'
gem 'name', 'git.github....'
group :development do
  xxx
end

目录结构

  • public:

Active Record Basics

  • ORM
  • 约定大于配置
  • 单复数（model）
  • 事务transaction 、 锁
  • form_for (errors/notification等)
  • 回调

Activie Record Migration

  • 索引

Active Record Associations 关系

关系

  • 主键、外键
  • 多态： polymorphic
  • 自关联
  • Controlling Caching 控制缓存

  • inverse_of 缓存数据改变控制

  • belongs_to 附加方法
  • include (n+1次查询)
  • source/source_type
  • present?/presentce/blank/count/exists?
多对多的自引用
class Friendship < ApplicationRecord
  belongs_to :followers, class_name: 'User', foreign_key: :user_id
  belongs_to :friends, class_name: 'User', foreign_key: :friend_id
end

class User < ApplicationRecord
  has_many :friendships, class_name: 'Friendship', foreign_key: :user_id
  has_many :friend_followers, class_name: 'Friendship', foreign_key: :friend_id

  has_many :friends, through: :friendships
  has_many :followers, through: :friend_followers# , class_name: 'Friendship', source: 'User'
end
  • Relation(ActiveRecord)
  • 查询（单条、多条）
  • distinct去重
  • limit、offset分页
  • group、having（分组、分组后查询）
  • reverse、unscope
  • 乐观锁（可访问不可更改）、悲观锁（不可访问）
  • inner、left、right、outer join
  • include （预防n+1次查询）
  • incldue和join区别
  • Using conditionals
  • pluck 神奇set、get
  • to_sql 生成sql语句
  • explain 性能分析

Active Model Basics

  • Attribute Methods
  • Callbacks
  • Conversion
  • Dirty
  • Validations
  • Naming
  • Model (store_accessor)(Marshal)
  • Translation
  • SecurePassword

。