Rails fields_for not working

Question

我正在嘗試使用fields_for並創建一個嵌套表單，但只有一個文本字段顯示爲空白。我有3 crewmember記錄。

crewmember模型：

class Crewmember < ActiveRecord::Base 
belongs_to :production 
belongs_to :callsheet 

validates :firstname, presence: true 
validates :email, presence: true 

def name 
    "#{firstname} #{lastname}" 
end 

end 

callsheet模型

class Callsheet < ActiveRecord::Base 
attr_accessible :crewmembers_params 
has_many :castmembers 
has_many :crewmembers 

accepts_nested_attributes_for :crewmembers 
end 

callsheets控制器

class CallsheetsController < ApplicationController 
    def index 
     @callsheets = Callsheet.all 
     @departments = Department.where(production_id: current_user.default_working_production_id) 
    end 

    def show 
     @callsheet = Callsheet.find(params[:id]) 
    end 

    def new 
     @callsheet = Callsheet.new 
     @departments = Department.where(production_id: current_user.default_working_production_id) 
    end 

    def edit 
     @callsheet = Callsheet.find(params[:id]) 
    end 

    def create 
     @callsheet = Callsheet.new(callsheets_params) 
     @Callsheet.production_id = current_user.default_working_production_id 


     if @callsheets.save 
      redirect_to callsheet_path 
     else 
      render 'new' 
     end 
    end 

    def update 
     @callsheet = Callsheet.find(params[:id]) 

     if @callsheet.update(callsheets_params) 
      redirect_to callsheet_path, :notice => "callsheets successfully updated." 
     else 
      render 'edit', :notice => "callsheets not updated." 
     end 
    end 

    def destroy 
     @callsheet = Callsheet.find(params[:id]) 
     @callsheet.destroy 

     redirect_to callsheets_path 
    end 

    private 
     def callsheets_params 
      params.require(:callsheet).permit(:crewmembers_params [:id, :firstname]) 

     end 
end 

形式爲新callsheet：

<%= form_for @callsheet do |f| %> 
    <% if @callsheet.errors.any? %> 
    <div id="error_explanation" class="alert alert-danger"> 
     <strong> 
     <%= pluralize(@callsheet.errors.count, "error") %> prohibited 
     this call sheet from being saved: 
     </strong> 
     <ul> 
     <% @callsheet.errors.full_messages.each do |msg| %> 
      <li><%= msg %></li> 
     <% end %> 
     </ul> 
    </div> 
    <% end %> 

    <%= f.fields_for :crewmember do |crewmember| %> 
    <fieldset> 
     <%= crewmember.label :firstname, "First Name" %><br /> 
     <%= crewmember.text_field :firstname %> 
    </fieldset> 
    <% end %> 

<% end %> 

Answer 1

你不需要attr_accessible（這隻適用於Rails 3）。

你也應該所有模型重命名爲snake_case，與CamelCase引用：

#app/models/call_sheet.rb 
class CallSheet < ActiveRecord::Base 
    has_many :cast_members 
    has_many :crew_members 
    accepts_nested_attributes_for :crew_members 
end 

如同fields_for自定義，還需要建立相關的對象（如果您要創建一個new記錄） （你不需要如果editing做到這一點）：

#app/controllers/call_sheets_controller.rb 
class CallSheetsController < ApplicationController 
    before_action :set_departments 

    def new 
     @callsheet = Callsheet.new 
     @callsheet.crew_members.build 
    end 

    def edit 
     @callsheet = Callsheet.find params[:id] 
    end 

    def update 
     @callsheet = Callsheet.find params[:id] 
     @callsheet.update callsheet_params 
    end 

    private 

    def set_departments 
     @departments = Department.where(production_id: current_user.default_working_production_id) 
    end 

    def callsheet_params 
     params.require(:callsheet).permit(crew_members_attributes: [:id, :firstname]) 
    end 
end 

這將允許你使用：

<%= form_for @callsheet do |f| %> 
    <%= f.fields_for :crew_members do |crewmember| %> 
     <%= crewmember.label :firstname, "First Name" %><br /> 
     <%= crewmember.text_field :firstname %> 
    <% end %> 
    <%= f.submit %> 
<% end %> 

-

當通過fields_for通過嵌套的屬性，你需要幾個組件：

• 在父模型的正確關聯
• 相關模型的實例化版本（@parent.build_child）
• 正確fields_for定義
• 傳遞正確parameters通過你的控制器

我已經概述瞭如何實現上述，所有你不正確。

---

您還可以在同一呼叫聲明多個驗證：

#app/models/crew_member.rb 
class CrewMember < ActiveRecord::Base 
    validates :firstname, :email, presence: true 
end