ruby on rails 创建新条目

Question

我有一个使用 Ruby on Rails 开发的 Web 应用程序，我的所有 CRUD 操作都运行良好。当我创建一个新项目时，会显示一个新表单，我可以填写新项目的所有字段。

由于多个项目有很多相同的字段，我想添加一个像“复制”这样的操作，以便我可以从现有项目创建一个新项目，所有表单条目都相同，那么我只需对新项目进行一些小改动并在数据库中更新它。

这是我的行为

class ProjectsController < ApplicationController

# GET /projects/1
# GET /projects.1.json
def index
  @projects = Project.all

  respond_to do |format|
    format.html # index.html.erb
    format.json { render :json => @projects }
  end
end

# GET /projects/1
# GET /projects/1.json
def show
  @project = Project.find(params[:id])

  respond_to do |format|
    format.html # show.html.erb
    format.json { render :json => @project }
  end
end

# GET /projects/new
# GET /projects/new.json
def new
  @project = Project.new

  respond_to do |format|
    format.html # new.html.erb
    format.json { render :json => @project }
  end
end

# GET /projects/1/edit
def edit
  @project = Project.find(params[:id])
end

# POST /projects
# POST /projects.json
def create
  @project = Project.new(params[:project])

  respond_to do |format|
    if @project.save
    format.html { redirect_to @project, :notice => 'Project was successfully created.' }
      format.json { render :json => @project, :status => :created, :location => @project }
    else
      format.html { render :action => "new" }
      format.json { render :json => @project.errors, :status => :unprocessable_entity }
    end
  end
end

# POST /projects/1
# PUT /projects/1.json
def update
  @project = Project.find(params[:id])

  respond_to do |format|
    if @project.update_attributes(params[:project])
      format.html { redirect_to @project, :notice => 'Project was successfully updated.' }
      format.json { head :ok }
    else
      format.html { render :action => "edit" }
      format.json { render :json => @project.errors, :status => :unprocessable_entity }
    end
  end
end

# DELETE /projects/1
# DELETE /projects/1.json
def destroy
  @project = Project.find(params[:id])
  @project.destroy

  respond_to do |format|
    format.html { redirect_to projects_url }
    format.json { head :ok }
  end
end
end

在这种情况下，我的“复制”或“复制”操作会是什么样子？

Answer 1

我会尝试这样的事情：

# in the routes.rb
resources :projects do
  get 'dublicate', :on => :member
end

这允许您在如下视图中建立指向重复操作的链接：link_to('duplicate', dublicate_project_path(@project))

# in the controller
def dublicate
  existing = Project.find(params[:id])
  @project = existing.dup

  respond_to do |format|
    format.html { render :new } 
    format.json { render :json => @project }
  end
end

这会将现有项目的属性（没有 id 字段）复制（参见：http://apidock.com/rails/ActiveRecord/Core/dup）到一个新项目中，然后显示带有预填充字段的新页面。

Answer 2

这样的事情怎么样：

def duplicate
  old_project = Project.find(params[:id])
  attributes = old_project.attributes.except(:id, :created_at, :updated_at)
  @project = Project.new(attributes)
  render :new
end

或许：

def duplicate
  old_project = Project.find(params[:id])
  attributes = old_project.attributes.except(:id, :created_at, :updated_at)
  @project = Project.new(attributes)
  if @project.save
    redirect_to project_path
  else
    render :edit
  end
end

请注意，如果您使用strong_params，您可能必须单独分配参数以防止出现禁止属性错误。

正如 cmets 中指出的那样，您