ruby-on-rails - Rails 关系 (has_many/belongs_to) 已完成

Question

所以我已经有很长一段时间没有玩过人际关系了，我想确保我做对了。

在我的客户模型中，我有:

class Client < ApplicationRecord
   has_many :projects, dependent: :destroy
end

在我的项目模型中，我有:

class Project < ApplicationRecord
   belongs_to :client
end

所以我知道那已经定了。然后抓取我放入项目 Controller 的项目:

def create
 @client = Client.find(params[:client_id])
 @project = @client.project.new(project_params)
 flash[:notice] = "Project created successfully" if @client.project << @project
 respond with @project, location: admin_project_path
end

我是否需要在我的节目中加入同样的东西？

关于人际关系我还缺少什么吗？

Answer 1

我会这样想:

def create
  @client = Client.find(params[:client_id])
  @project = @client.project.new(project_params)
  flash[:notice] = "Project created successfully" if @client.project << @project
  respond with @project, location: admin_project_path
end

看起来更像是:

def create
  @client = Client.find(params[:client_id])
  @project = @client.projects.new(project_params)
  if @project.save
    # do success stuff 
  else
    # do failure stuff
  end
end

注意

@project = @client.project.new(project_params)

应该是:

@project = @client.projects.new(project_params)

正如 Yechiel K 所说，不需要做:

@client.project << @project

开始于:

@project = @client.projects.new(project_params)

将在新的@project 上自动设置client_id。顺便说一句，如果你想手动添加一个project到client，那么它是:

@client.projects << @project

(注意 projects 与 project。)

如果没有带有params[:client_id]的client，那么@client = Client.find(params[:client_id] ) 会抛出错误。您可能应该包括一个救援 block 。或者，我更喜欢:

def create
  if @client = Client.find_by(id: params[:client_id])
    @project = @client.projects.new(project_params)
    if @project.save
      # do success stuff 
    else
      # do failure stuff
    end
  else
    # do something when client not found
  end
end

此外，respond with 也不是问题。 respond_with 是一回事。 (我相信它已被移动到一个单独的 gem，responders。)如果您需要不同的响应，例如，对于 html 和 js，您的代码并不清楚。如果不是，那么我认为它更像是:

def create
  if @client = Client.find_by(id: params[:client_id])
    @project = @client.projects.new(project_params)
    if @project.save
      flash[:notice] = "Project created successfully"
      redirect_to [@client, @project]
    else
      # do failure stuff
    end
  else
    # do something when client not found
  end
end

这假设您的路线看起来像:

Rails.application.routes.draw do

  resources :clients do 
    resources :projects
  end

end

在这种情况下，rails 会将 [@client, @project] 解析为正确的路由/路径。

正如 DaveMongoose 提到的，您可以将 @client = Client.find_by(id: params[:client_id]) 移动到 before_action 中。这很常见。 Here's关于为什么不这样做的讨论。就个人而言，我曾经像这样使用 before_action，但现在不用了。作为替代方案，您可以这样做:

class ProjectsController < ApplicationController 

  ...

  def create 
    if client 
      @project = client.projects.new(project_params)
      if @project.save
        flash[:notice] = "Project created successfully"
        redirect_to [client, @project]
      else
        # do failure stuff
      end
    else
      # do something when client not found
    end
  end

private

  def client 
    @client ||= Client.find_by(id: params[:client_id])
  end

end

更进一步，您可以:

class ProjectsController < ApplicationController 

  ...

  def create 
    if client 
      if new_project.save
        flash[:notice] = "Project created successfully"
        redirect_to [client, new_project]
      else
        # do failure stuff
      end
    else
      # do something when client not found
    end
  end

private

  def client 
    @client ||= Client.find_by(id: params[:client_id])
  end

  def new_project 
    @new_project ||= client.projects.new(project_params)
  end

end