Question

我有一个部分路由是资源的会话：会话，但是当我尝试在导航栏中呈现这个部分时（列出所有活动的会话），我得到一个未定义的方法错误。

undefined method `author' for nil:NilClass

现在我正在做<%= render 'conversations/conversation' %>

是否有一种特殊方式可以在您的网站上呈现您的部分内容？

编辑：提供代码

会话/ _conversation.html.erb

<div>
  From <strong><%= conversation.author.email %></strong> to
  <strong><%= conversation.receiver.email %> (<%#= conversation.receiver.online? ? 'online' : 'offline' %>)</strong>
  <br>
  <%= link_to 'View conversation', conversation_path(conversation) %>
  <hr>
</div>

布局/ _navigation.html.erb

  <%= render 'conversations/conversation' %>

路由

  #Chat
  resources :conversations
  resources :personal_messages
  resources :users
  mount ActionCable.server => '/cable'

EDIT2：

conversations_controller.rb

class ConversationsController < ApplicationController
  before_action :set_conversation
  before_action :check_participating!, except: [:index]

  def index
    @conversations = Conversation.participating(current_user).order('updated_at DESC')
    respond_to do |format|
      format.html
      format.js
    end
  end

  def show
    @personal_message = PersonalMessage.new
    @conversations = Conversation.participating(current_user)
  end

  private

  def set_conversation
    @conversation = Conversation.find_by(id: params[:id])
  end

  def check_participating!
    redirect_to root_path unless @conversation && @conversation.participates?(current_user)
  end
end

的ApplicationController

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception

  before_action :authenticate_user!

end

Answer 1

执行此操作的常规方法是：

conversation

如果您没有提供参考对象，则没有数据绑定到本地nil变量，您会收到long batteryLevelPercent = beacon.getDataFields().get(0);引用错误。

在rails应用程序的任何位置渲染部分内容

1 个答案: