AbstractController::DoubleRenderError (Render and/or redirect were called multiple times in this action

Question

Im create a messages system where one user send message and the other user receive the message with realtime update. It was working before but now im getting in error and nothing render or get refreshed.

AbstractController::DoubleRenderError (Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action. Also note that neither redirect nor render terminate execution of the action, so if you want to exit an action after redirecting, you need to do something like "redirect_to(...) and return".):

here is messages_controller.rb

class MessagesController < ApplicationController
before_action :authenticate_user!
before_action :set_conversation

def index
   if current_user == @conversation.sender || current_user == 
     @conversation.recipient
     @other = current_user == @conversation.sender ? 
     @conversation.recipient : @conversation.sender
     @messages = @conversation.messages.order("created_at DESC")
   else
   redirect_to conversations_path, alert: "You don't have permission to view this."
   end
   end

def create
  @message = @conversation.messages.new(message_params)
  @messages = @conversation.messages.order("created_at DESC")

 if @message.save
   ActionCable.server.broadcast "conversation_#{@conversation.id}", message: render_message(@message)
   redirect_to conversation_messages_path(@conversation)
 end

end

private

 def render_message(message)
   self.render(partial: 'messages/message', locals: {message: message})
 end

 def set_conversation
   @conversation = Conversation.find(params[:conversation_id])
 end

 def message_params
   params.require(:message).permit(:context, :user_id)
 end
end

I know the error is coming from here

 if @message.save
   ActionCable.server.broadcast "conversation_#{@conversation.id}", message: render_message(@message)
   redirect_to conversation_messages_path(@conversation)
 end

Answer 1

the issue was with Connection.rb It was like this

module ApplicationCable
class Connection < ActionCable::Connection::Base
   identified_by :current_user

   def connect
   self.current_user = find_verified_user
   logger.add_tags 'ActionCable', current_user.name
   end

   protected
    def find_verified_user
      verified_user = User.find_by(id: cookies.signed['user.id'])
      if verified_user && cookies.signed['user.expires_at'] > Time.now
        verified_user
      else
        reject_unauthorized_connection
      end
    end
  end
end

and when i changed to this it worked

module ApplicationCable
   class Connection < ActionCable::Connection::Base
   end
end

Answer 2

In Message.rb

 after_create_commit { MessageJob.perform_later self }

and create MessageJob

class MessageJob < ApplicationJob
  queue_as :default

  def perform(message)
   ActionCable.server.broadcast "conversation_#{message.conversation.id}", message: render_message(message)
  end

  private


def render_message(message)
   ApplicationController.renderer.render(partial: 'messages/message', locals: {message: message})
 end