Rails：Polymorphic assosiation和accepts_nested_attributes

附件不会保存。 我在这里缺少什么？ 在我的应用程序中，我有一个项目，每个项目用户都可以上传许多资产。 上传由载波完成。

这是模特

class Project  :assetable,dependent: :destroy accepts_nested_attributes_for :assets, :allow_destroy => true end class Asset  true mount_uploader :attachment, AttachmentUploader #carrierwave validates :attachment, presence: true validates :project_id, presence: true end 

这些是我的project_controller中的动作

  def new @project = Project.new @asset = @project.assets.build end def create @project = Project.new(project_params) @project.assets.build respond_to do |format| if @project.save format.html { redirect_to @project, notice: 'Project was successfully created.' } format.json { render :show, status: :created, location: @project } else format.html { render :new } format.json { render json: @project.errors, status: :unprocessable_entity } end end def project_params params.require(:project).permit(:user_id, :summary, :start_date,assets_attributes: [:id, :project_id, :attachment,:user_id] ) end 

这就是表单的样子

   {:multipart => true } do |f| %>  
 
   
 
  
  
  
  

Answer 1

schema.rb

 create_table "assets", force: true do |t| t.string "assetable_id" t.string "assetable_type" t.string "attachment" t.datetime "created_at" t.datetime "updated_at" end create_table "projects", force: true do |t| t.string "user_id" t.string "summary" t.datetime "created_at" t.datetime "updated_at" end 

项目/ _form.html.erb

  <%= form_for @project, :html => {:multipart => true } do |f| %> <% if @project.errors.any? %> 
 <%= @project.errors.inspect %> 
 <% end %> <%= f.label :summary %> <%= f.text_field :summary %> <%= f.fields_for :assets do |p| %> 
 <%= p.label :attachment %>
 <%= p.file_field :attachment %> <%= p.hidden_field :assetable_id %> <%= p.hidden_field :assetable_type %> 
 <% end %> 
 <%= f.submit %> 
 <% end %> 

projects_controller.rb

  # GET /projects/new def new @project = Project.new @project.assets.build end # POST /projects # POST /projects.json def create @project = Project.new(project_params) respond_to do |format| if @project.save format.html { redirect_to @project, notice: 'Project was successfully created.' } format.json { render :show, status: :created, location: @project } else format.html { render :new } format.json { render json: @project.errors, status: :unprocessable_entity } end end end private # Never trust parameters from the scary internet, only allow the white list through. def project_params params.require(:project).permit(:user_id, :summary, :start_date, assets_attributes: [:id, :assetable_id, :assetable_type, :attachment, :user_id] ) end 

project.rb

 class Project < ActiveRecord::Base has_many :assets, :as => :assetable, dependent: :destroy accepts_nested_attributes_for :assets, :allow_destroy => true end 

asset.rb

 class Asset < ActiveRecord::Base belongs_to :project belongs_to :assetable, :polymorphic => true mount_uploader :attachment, AttachmentUploader #carrierwave validates :attachment, presence: true validates :assetable_type, presence: true end 

在旁边

由于您根据上一个问题提出了这个问题，您问我只会提到：如果您希望资产类的实例属于不同类型的类（即项目以外的其他类型），您只想使用多态关联。