Question

我有这种一对多的关系：

class Programa < ActiveRecord::Base
  attr_accessible :descripcion, :nombre, :roles_attributes
  has_many :roles, :dependent => :restrict
  accepts_nested_attributes_for :roles
    ...
end

class Role < ActiveRecord::Base
  attr_accessible :description, :name, :programa_id
  belongs_to :programa
    ...
end

它适用于rails控制台：

> params = { programa: { nombre: 'nuevo', roles_attributes: [ {name: 'role1'}, {name: 'role2'}] }}
> p = Programa.create(params[:programa])
> p
 => #<Programa id: 7, nombre: "nuevo", descripcion: nil, created_at: "2013-10-09 14:07:46", updated_at: "2013-10-09 14:07:46">
> p.roles
 => [#<Role id: 15, name: "role1", description: nil, created_at: "2013-10-09 14:07:46", updated_at: "2013-10-09 14:07:46", programa_id: 7>, #<Role id: 16, name: "role2", description: nil, created_at: "2013-10-09 14:07:46", updated_at: "2013-10-09 14:07:46", programa_id: 7>]

但是我无法在app / views / programas / _form中使其工作：

<%= form_for(@programa) do |f| %>
  <%= render 'shared/form_error_messages', object: f.object %>
  <div class="field">
    <%= f.label :nombre %>
    <%= f.text_field :nombre %>
  </div>
  <div class="field">
    <%= f.label :descripcion %>
    <%= f.text_field :descripcion %>
  </div>

  <% f.fields_for :roles do |builder| %>
    <div class="field">
      <%= builder.label :name %>
      <%= builder.text_field :name %>
    </div>
    <div class="field">
      <%= builder.label :description %>
      <%= builder.text_field :description %>
    </div>
  <% end %>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

我还需要添加或删除任何其他内容才能使我的表单显示角色嵌套属性吗？

这是我的程序控制器：

class ProgramasController < ApplicationController
  # GET /programas
  # GET /programas.json
  def index
    @programas = Programa.all

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

  # GET /programas/1
  # GET /programas/1.json
  def show
    @programa = Programa.find(params[:id])

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

  # GET /programas/new
  # GET /programas/new.json
  def new
    @programa = Programa.new
    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @programa }
    end
  end

  # GET /programas/1/edit
  def edit
    @programa = Programa.find(params[:id])
  end

  # POST /programas
  # POST /programas.json
  def create
    @programa = Programa.new(params[:programa])

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

  # PUT /programas/1
  # PUT /programas/1.json
  def update
    @programa = Programa.find(params[:id])

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

  # DELETE /programas/1
  # DELETE /programas/1.json
  def destroy
    @programa = Programa.find(params[:id])
    @programa.destroy

    respond_to do |format|
      format.html { redirect_to programas_url }
      format.json { head :no_content }
    end
  end
end

我只希望嵌套属性只显示在编辑和显示操作中。

Answer 1

嵌套属性的表单只会显示是否有实际要显示的数据，即。如果您的Programa实例有一个或多个与之关联的角色。

在渲染表单之前，这可以像控制器中的@programa.roles.build一样简单，以添加新角色。将呈现任何现有角色。

编辑：您还需要实际渲染表单，即。 <%= f.fields_for（请注意缺少=）。

Rails形式与嵌套属性（accepts_nested_attributes_for）

1 个答案: