Rails 3：3个模型和路由错误

Question

我有一些项目，有门票，然后有评论。我相信模型关联的代码是正确的吗？

class Comment < ActiveRecord::Base
  belongs_to :ticket, :dependent => :destroy
  belongs_to :project
end

class Ticket < ActiveRecord::Base
  belongs_to :project
  has_many :comments, :dependent => :destroy
end

class Project < ActiveRecord::Base
  has_many :tickets
  has_many :comments, :through => :tickets
end

在单击按钮之前，路线是：

http://localhost:3000/projects/7/tickets/16

当我单击提交按钮时，路线更改为

http://localhost:3000/tickets/16/comments

如何阅读：

http://localhost:3000/projects/7/tickets/16/

提交新评论后显示在 tickets/:id 上看法？

当我提交并创建票证对象上的注释时，它给出了一个活动记录错误：

ActiveRecord::RecordNotFound in CommentsController#create
Couldn't find Project without an ID

使用此控制器：

def create
  @project = Project.find(params[:project_id])
  @ticket = @project.tickets.find(params[:ticket_id])
  @comment = @ticket.comments.new(params[:comment])
  if @comment.save
    redirect_to project_ticket_path(@project, @ticket)
  else
  end
end

Rails 的新功能，但它必须与模型关联或路由...

我的路由链接...

Kaledoscope:ticket_taker Evolution$ rake routes
    project_tickets GET    /projects/:project_id/tickets(.:format)          {:action=>"index", :controller=>"tickets"}
                    POST   /projects/:project_id/tickets(.:format)          {:action=>"create", :controller=>"tickets"}
 new_project_ticket GET    /projects/:project_id/tickets/new(.:format)      {:action=>"new", :controller=>"tickets"}
edit_project_ticket GET    /projects/:project_id/tickets/:id/edit(.:format) {:action=>"edit", :controller=>"tickets"}
     project_ticket GET    /projects/:project_id/tickets/:id(.:format)      {:action=>"show", :controller=>"tickets"}
                    PUT    /projects/:project_id/tickets/:id(.:format)      {:action=>"update", :controller=>"tickets"}
                    DELETE /projects/:project_id/tickets/:id(.:format)      {:action=>"destroy", :controller=>"tickets"}
           projects GET    /projects(.:format)                              {:action=>"index", :controller=>"projects"}
                    POST   /projects(.:format)                              {:action=>"create", :controller=>"projects"}
        new_project GET    /projects/new(.:format)                          {:action=>"new", :controller=>"projects"}
       edit_project GET    /projects/:id/edit(.:format)                     {:action=>"edit", :controller=>"projects"}
            project GET    /projects/:id(.:format)                          {:action=>"show", :controller=>"projects"}
                    PUT    /projects/:id(.:format)                          {:action=>"update", :controller=>"projects"}
                    DELETE /projects/:id(.:format)                          {:action=>"destroy", :controller=>"projects"}
    ticket_comments GET    /tickets/:ticket_id/comments(.:format)           {:action=>"index", :controller=>"comments"}
                    POST   /tickets/:ticket_id/comments(.:format)           {:action=>"create", :controller=>"comments"}
 new_ticket_comment GET    /tickets/:ticket_id/comments/new(.:format)       {:action=>"new", :controller=>"comments"}
edit_ticket_comment GET    /tickets/:ticket_id/comments/:id/edit(.:format)  {:action=>"edit", :controller=>"comments"}
     ticket_comment GET    /tickets/:ticket_id/comments/:id(.:format)       {:action=>"show", :controller=>"comments"}
                    PUT    /tickets/:ticket_id/comments/:id(.:format)       {:action=>"update", :controller=>"comments"}
                    DELETE /tickets/:ticket_id/comments/:id(.:format)       {:action=>"destroy", :controller=>"comments"}
            tickets GET    /tickets(.:format)                               {:action=>"index", :controller=>"tickets"}
                    POST   /tickets(.:format)                               {:action=>"create", :controller=>"tickets"}
         new_ticket GET    /tickets/new(.:format)                           {:action=>"new", :controller=>"tickets"}
        edit_ticket GET    /tickets/:id/edit(.:format)                      {:action=>"edit", :controller=>"tickets"}
             ticket GET    /tickets/:id(.:format)                           {:action=>"show", :controller=>"tickets"}
                    PUT    /tickets/:id(.:format)                           {:action=>"update", :controller=>"tickets"}
                    DELETE /tickets/:id(.:format)                           {:action=>"destroy", :controller=>"tickets"}
               root        /(.:format)                                      {:controller=>"projects", :action=>"index"}

Answer 1

在你的控制器中你需要做一些轻微的改变。在您拥有 @ticket.comments.new 的地方，您应该拥有 @ticket.comments.build(params[:comment])。例如：

def create
  @project = Project.find(params[:project_id])
  @ticket = @project.tickets.find(params[:ticket_id])
  @comment = @ticket.comments.build(params[:comment])
  if @comment.save
    redirect_to project_ticket_path(@project, @ticket)
  end
end

Build 将构建一个新评论，并将 ticket_id 设置为父级的 id。如果您执行new，它将无法正确设置ticket_id，因此它将无法重定向到自@ticket以来给定的路线code> 和 @comment 不会关联。

来自 Rails 文档：

collection.build(attributes = {})
返回一个或多个集合类型的新对象，这些对象已使用属性实例化并通过外键链接到该对象，但尚未保存。