问如何使用action cable向rails中的单个用户发送通知

EN

class WebNotificationsChannel < ApplicationCable::Channel
  def subscribed
    # stream_from "some_channel"
    stream_from "notifications:#{current_user.id}"
  end
end

@payments = Payment.all
@payments.each do |payment|
  ActionCable.server.broadcast "notifications:#{payment.user_id}", html: notification_render(notification) , count: unseen_notification_number
end

def notification_render(notification)
  render(partial: 'homepage/notification', locals: {notification: notification})
end

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".):