Ruby on Rails 最佳实践

ClownF原创2024/1/18大约 3 分钟

Ruby on Rails 最佳实践

Rails 是一个优雅而强大的 Web 框架，遵循"约定优于配置"的理念，让开发更高效。

Rails 核心理念

MVC 架构

# Model (app/models/user.rb)
class User < ApplicationRecord
  has_many :posts
  validates :email, presence: true, uniqueness: true
  
  def full_name
    "#{first_name} #{last_name}"
  end
end

# Controller (app/controllers/users_controller.rb)
class UsersController < ApplicationController
  def index
    @users = User.all
  end
  
  def show
    @user = User.find(params[:id])
  end
end

# View (app/views/users/index.html.erb)
<% @users.each do |user| %>
  <div class="user">
    <%= link_to user.full_name, user_path(user) %>
  </div>
<% end %>

路由设计

# config/routes.rb
Rails.application.routes.draw do
  root 'home#index'
  
  resources :users do
    resources :posts, only: [:index, :show]
    member do
      get 'profile'
    end
    collection do
      get 'search'
    end
  end
  
  namespace :admin do
    resources :users
  end
end

Active Record

模型关联

class User < ApplicationRecord
  has_many :posts, dependent: :destroy
  has_many :comments
  has_one :profile
  belongs_to :organization, optional: true
end

class Post < ApplicationRecord
  belongs_to :user
  has_many :comments
  has_many :tags, through: :post_tags
  
  validates :title, presence: true, length: { minimum: 5 }
  validates :content, presence: true
  
  scope :published, -> { where(published: true) }
  scope :recent, -> { order(created_at: :desc).limit(10) }
end

查询优化

# N+1 查询问题
# 坏例子
users = User.all
users.each do |user|
  puts user.posts.count  # 每次都会查询数据库
end

# 好例子 - 使用 includes
users = User.includes(:posts)
users.each do |user|
  puts user.posts.count  # 使用预加载的数据
end

# 复杂查询
User.joins(:posts)
    .where(posts: { published: true })
    .select('users.*, COUNT(posts.id) as posts_count')
    .group('users.id')
    .having('COUNT(posts.id) > ?', 5)

Service Objects

# app/services/user_registration_service.rb
class UserRegistrationService
  def initialize(params)
    @params = params
  end
  
  def call
    user = User.new(@params)
    
    ActiveRecord::Base.transaction do
      if user.save
        send_welcome_email(user)
        create_default_profile(user)
        { success: true, user: user }
      else
        { success: false, errors: user.errors }
      end
    end
  rescue => e
    { success: false, errors: [e.message] }
  end
  
  private
  
  def send_welcome_email(user)
    UserMailer.welcome_email(user).deliver_later
  end
  
  def create_default_profile(user)
    user.create_profile(bio: 'New user')
  end
end

# 使用
result = UserRegistrationService.new(user_params).call
if result[:success]
  redirect_to user_path(result[:user])
else
  render :new, errors: result[:errors]
end

后台任务

# app/jobs/report_generation_job.rb
class ReportGenerationJob < ApplicationJob
  queue_as :default
  
  retry_on StandardError, wait: 5.seconds, attempts: 3
  
  def perform(user_id, report_type)
    user = User.find(user_id)
    report = generate_report(user, report_type)
    
    ReportMailer.send_report(user, report).deliver_now
  end
  
  private
  
  def generate_report(user, report_type)
    # 生成报告逻辑
  end
end

# 调用
ReportGenerationJob.perform_later(current_user.id, 'monthly')

测试

RSpec 测试

# spec/models/user_spec.rb
RSpec.describe User, type: :model do
  describe 'validations' do
    it { should validate_presence_of(:email) }
    it { should validate_uniqueness_of(:email) }
  end
  
  describe 'associations' do
    it { should have_many(:posts) }
    it { should have_one(:profile) }
  end
  
  describe '#full_name' do
    it 'returns the full name' do
      user = User.new(first_name: 'John', last_name: 'Doe')
      expect(user.full_name).to eq('John Doe')
    end
  end
end

# spec/requests/users_spec.rb
RSpec.describe 'Users API', type: :request do
  describe 'GET /users' do
    it 'returns all users' do
      create_list(:user, 3)
      
      get '/users'
      
      expect(response).to have_http_status(200)
      expect(JSON.parse(response.body).size).to eq(3)
    end
  end
end

API 开发

# app/controllers/api/v1/users_controller.rb
module Api
  module V1
    class UsersController < ApplicationController
      before_action :authenticate_user!
      
      def index
        users = User.page(params[:page]).per(20)
        render json: users, each_serializer: UserSerializer
      end
      
      def create
        user = User.new(user_params)
        
        if user.save
          render json: user, status: :created
        else
          render json: { errors: user.errors }, status: :unprocessable_entity
        end
      end
      
      private
      
      def user_params
        params.require(:user).permit(:email, :name, :password)
      end
    end
  end
end

# app/serializers/user_serializer.rb
class UserSerializer < ActiveModel::Serializer
  attributes :id, :email, :name, :created_at
  has_many :posts
end

性能优化

缓存

# 片段缓存
<% cache @product do %>
  <%= render @product %>
<% end %>

# 俄罗斯套娃缓存
<% cache ['products', @products.maximum(:updated_at)] do %>
  <% @products.each do |product| %>
    <% cache product do %>
      <%= render product %>
    <% end %>
  <% end %>
<% end %>

# Low-Level 缓存
def expensive_operation
  Rails.cache.fetch('expensive_operation', expires_in: 12.hours) do
    # 耗时操作
  end
end

数据库优化

# 添加索引
class AddIndexToUsers < ActiveRecord::Migration[7.0]
  def change
    add_index :users, :email, unique: true
    add_index :posts, [:user_id, :created_at]
  end
end

# 批量操作
User.where(active: false).find_in_batches(batch_size: 1000) do |users|
  users.each(&:deactivate!)
end

最佳实践

遵循 Rails 约定: 减少配置，提高效率
保持 Controller 简洁: 业务逻辑放在 Service/Model 中
写测试: TDD/BDD 开发流程
使用 N+1 检测工具: bullet gem
代码审查: Rubocop 静态分析

常用 Gems

# Gemfile
gem 'devise'          # 用户认证
gem 'pundit'          # 授权
gem 'kaminari'        # 分页
gem 'sidekiq'         # 后台任务
gem 'fast_jsonapi'    # JSON 序列化
gem 'bullet'          # N+1 查询检测
gem 'rubocop-rails'   # 代码规范

总结

Rails 通过约定和最佳实践，让 Web 开发变得优雅而高效。掌握这些最佳实践，能够构建出高质量的 Rails 应用。