不允許的參數：songs_attributes

Question

我的嵌套屬性有問題。我希望有人能夠訪問我的網站併爲活動添加歌曲。如果他們爲該事件提供派對代碼，他們只能添加這些歌曲。我想我的嵌套屬性設置正確，但我得到一個未經許可的參數錯誤。

活動控制器：

class EventsController < ApplicationController 
    def new 
     @event = Event.new 
     @event.songs.build 
    end 

    def show 
     @event = Event.find(params[:id]) 
     @songs = @event.songs.paginate(page: params[:page]) 
    end 

    def create 
     @event = current_user.events.build(event_params) 
     if @event.save 
      flash[:success] = "Event Created!" 
      redirect_to user_path(@event.user) 
     else 
      render 'welcome/index' 
     end 
    end 

    def destroy 
    end 

    private 

     def event_params 
     params.require(:event).permit(:name, :partycode, song_attributes: [:artist, :title, :genre, :partycode]) 
     end 
end 

application_controller：

class ApplicationController < ActionController::Base 
    protect_from_forgery with: :exception 
    include SessionsHelper 
end 

這裏是在歌曲new.html.erb文件視圖，其中包含的代碼將歌曲添加到該事件，注意用戶在添加歌曲時未登錄：

<br> 
<br> 
<div class ="container"> 
    <div class="jumbotron"> 
    <%= form_for Event.new do |f| %> 
    <h3>Enter a song:</h3> 
    <%= f.fields_for :songs, Song.new do |song_form| %> 

     <%= song_form.collection_select(:event_id, Event.all, :id, :name) %> 
     <%= song_form.text_field :artist, placeholder: "Artist" %> 
     <%= song_form.text_field :title, placeholder: "Title" %> 
     <%= song_form.text_field :genre, placeholder: "Genre" %> 
    <% end %> 
    <%= link_to_add_fields "Add Song", f, :songs %> 
    <%= f.text_field :partycode %> 
    <%= f.submit "Submit", class: "btn btn-primary" %> 
    <% end %> 
    </div> 
</div> 

link_to_add_fields方法d是在application_helper.rb文件：

module ApplicationHelper 
    def link_to_add_fields(name, f, association) 
    new_object = f.object.send(association).klass.new 
    id = new_object.object_id 
    fields = f.fields_for(association, new_object, child_index: id) do |builder| 
     render("songs_fields", f: builder) 
    end 
    link_to(name, '#', class: "add_fields", data: {id: id, fields: fields.gsub("\n", "")}) 
    end 
end 

的songs_field部分被定義如下：

<fieldset> 
    <%= f.text_field :artist, placeholder: "Artist" %> 
    <%= f.text_field :title, placeholder: "Title" %> 
    <%= f.text_field :genre, placeholder: "Genre" %> 
</fieldset> 

的咖啡腳本，將字段：

$(document).on 'click', 'form .add_songs', (event) -> 
    time = new Date().getTime() 
    regexp = new RegExp($(this).data('event_id'), 'g') 
    $(this).before($(this).data('songs').replace(regexp, time)) 
    event.preventDefault() 

使人物從new.html.erb頁面將能夠從下拉菜單中選擇一個事件，然後按需添加更多的歌曲字段，然後爲他們挑選的某個事件輸入派對代碼。任何幫助，這將是太棒了！由於

編輯錯誤：

undefined method `events' for nil:NilClass 

Answer 1

在你EventsController，你的嵌套params爲在event_params方法

private 
    def event_params 
    params.require(:event).permit(:name, :partycode, song_attributes: [:artist, :title, :genre, :partycode]) 
    end 

拼寫爲song_attributes但你的錯誤說unpermitted parameter: songs_attributes。

你拼寫它incorrect.Change在EventsController你event_params方法在某處，代碼如下

private 
    def event_params 
    params.require(:event).permit(:name, :partycode, songs_attributes: [:artist, :title, :genre, :partycode]) 
    end