Action Cable 概觀

# app/channels/application_cable/connection.rb
module ApplicationCable
  class Connection < ActionCable::Connection::Base
    identified_by :current_user

    def connect
      self.current_user = find_verified_user
    end

    private
      def find_verified_user
        if verified_user = User.find_by(id: cookies.encrypted[:user_id])
          verified_user
        else
          reject_unauthorized_connection
        end
      end
  end
end

verified_user = User.find_by(id: cookies.encrypted["_session"]["user_id"])

# app/channels/application_cable/connection.rb
module ApplicationCable
  class Connection < ActionCable::Connection::Base
    rescue_from StandardError, with: :report_error

    private
      def report_error(e)
        SomeExternalBugtrackingService.notify(e)
      end
  end
end

# app/channels/application_cable/channel.rb
module ApplicationCable
  class Channel < ActionCable::Channel::Base
  end
end

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
end

# app/channels/appearance_channel.rb
class AppearanceChannel < ApplicationCable::Channel
end

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
  # Called when the consumer has successfully
  # become a subscriber to this channel.
  def subscribed
  end
end

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
  rescue_from "MyError", with: :deliver_error_message

  private
    def deliver_error_message(e)
      # broadcast_to(...)
    end
end

// app/javascript/channels/consumer.js
// Action Cable provides the framework to deal with WebSockets in Rails.
// You can generate new channels where WebSocket features live using the `bin/rails generate channel` command.

import { createConsumer } from "@rails/actioncable"

export default createConsumer()

// Specify a different URL to connect to
createConsumer('wss://example.com/cable')
// Or when using websockets over HTTP
createConsumer('https://ws.example.com/cable')

// Use a function to dynamically generate the URL
createConsumer(getWebSocketURL)

function getWebSocketURL() {
  const token = localStorage.get('auth-token')
  return `wss://example.com/cable?token=${token}`
}

// app/javascript/channels/chat_channel.js
import consumer from "./consumer"

consumer.subscriptions.create({ channel: "ChatChannel", room: "Best Room" })

// app/javascript/channels/appearance_channel.js
import consumer from "./consumer"

consumer.subscriptions.create({ channel: "AppearanceChannel" })

// app/javascript/channels/chat_channel.js
import consumer from "./consumer"

consumer.subscriptions.create({ channel: "ChatChannel", room: "1st Room" })
consumer.subscriptions.create({ channel: "ChatChannel", room: "2nd Room" })

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
  def subscribed
    stream_from "chat_#{params[:room]}"
  end
end

ActionCable.server.broadcast("chat_Best Room", { body: "This Room is Best Room." })

class PostsChannel < ApplicationCable::Channel
  def subscribed
    post = Post.find(params[:id])
    stream_for post
  end
end

PostsChannel.broadcast_to(@post, @comment)

// app/javascript/channels/chat_channel.js
import consumer from "./consumer"

consumer.subscriptions.create({ channel: "ChatChannel", room: "Best Room" }, {
  received(data) {
    this.appendLine(data)
  },

  appendLine(data) {
    const html = this.createLine(data)
    const element = document.querySelector("[data-chat-room='Best Room']")
    element.insertAdjacentHTML("beforeend", html)
  },

  createLine(data) {
    return `
      <article class="chat-line">
        <span class="speaker">${data["sent_by"]}</span>
        <span class="body">${data["body"]}</span>
      </article>
    `
  }
})

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
  def subscribed
    stream_from "chat_#{params[:room]}"
  end
end

// app/javascript/channels/chat_channel.js
import consumer from "./consumer"

consumer.subscriptions.create({ channel: "ChatChannel", room: "Best Room" }, {
  received(data) {
    this.appendLine(data)
  },

  appendLine(data) {
    const html = this.createLine(data)
    const element = document.querySelector("[data-chat-room='Best Room']")
    element.insertAdjacentHTML("beforeend", html)
  },

  createLine(data) {
    return `
      <article class="chat-line">
        <span class="speaker">${data["sent_by"]}</span>
        <span class="body">${data["body"]}</span>
      </article>
    `
  }
})

# Somewhere in your app this is called, perhaps
# from a NewCommentJob.
ActionCable.server.broadcast(
  "chat_#{room}",
  {
    sent_by: "Paul",
    body: "This is a cool chat app."
  }
)

# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
  def subscribed
    stream_from "chat_#{params[:room]}"
  end

  def receive(data)
    ActionCable.server.broadcast("chat_#{params[:room]}", data)
  end
end

// app/javascript/channels/chat_channel.js
import consumer from "./consumer"

const chatChannel = consumer.subscriptions.create({ channel: "ChatChannel", room: "Best Room" }, {
  received(data) {
    // data => { sent_by: "Paul", body: "This is a cool chat app." }
  }
})

chatChannel.send({ sent_by: "Paul", body: "This is a cool chat app." })

# app/channels/appearance_channel.rb
class AppearanceChannel < ApplicationCable::Channel
  def subscribed
    current_user.appear
  end

  def unsubscribed
    current_user.disappear
  end

  def appear(data)
    current_user.appear(on: data["appearing_on"])
  end

  def away
    current_user.away
  end
end

// app/javascript/channels/appearance_channel.js
import consumer from "./consumer"

consumer.subscriptions.create("AppearanceChannel", {
  // Called once when the subscription is created.
  initialized() {
    this.update = this.update.bind(this)
  },

  // Called when the subscription is ready for use on the server.
  connected() {
    this.install()
    this.update()
  },

  // Called when the WebSocket connection is closed.
  disconnected() {
    this.uninstall()
  },

  // Called when the subscription is rejected by the server.
  rejected() {
    this.uninstall()
  },

  update() {
    this.documentIsActive ? this.appear() : this.away()
  },

  appear() {
    // Calls `AppearanceChannel#appear(data)` on the server.
    this.perform("appear", { appearing_on: this.appearingOn })
  },

  away() {
    // Calls `AppearanceChannel#away` on the server.
    this.perform("away")
  },

  install() {
    window.addEventListener("focus", this.update)
    window.addEventListener("blur", this.update)
    document.addEventListener("turbo:load", this.update)
    document.addEventListener("visibilitychange", this.update)
  },

  uninstall() {
    window.removeEventListener("focus", this.update)
    window.removeEventListener("blur", this.update)
    document.removeEventListener("turbo:load", this.update)
    document.removeEventListener("visibilitychange", this.update)
  },

  get documentIsActive() {
    return document.visibilityState === "visible" && document.hasFocus()
  },

  get appearingOn() {
    const element = document.querySelector("[data-appearing-on]")
    return element ? element.getAttribute("data-appearing-on") : null
  }
})

# app/channels/web_notifications_channel.rb
class WebNotificationsChannel < ApplicationCable::Channel
  def subscribed
    stream_for current_user
  end
end

// app/javascript/channels/web_notifications_channel.js
// Client-side which assumes you've already requested
// the right to send web notifications.
import consumer from "./consumer"

consumer.subscriptions.create("WebNotificationsChannel", {
  received(data) {
    new Notification(data["title"], { body: data["body"] })
  }
})

# Somewhere in your app this is called, perhaps from a NewCommentJob
WebNotificationsChannel.broadcast_to(
  current_user,
  title: "New things!",
  body: "All the news fit to print"
)

development:
  adapter: async

test:
  adapter: test

production:
  adapter: redis
  url: redis://10.10.3.153:6381
  channel_prefix: appname_production

production:
  adapter: redis
  url: rediss://10.10.3.153:tls_port
  channel_prefix: appname_production
  ssl_params:
    ca_file: "/path/to/ca.crt"

config.action_cable.allowed_request_origins = ["https://rubyonrails.com", %r{http://ruby.*}]

config.action_cable.disable_request_forgery_protection = true

config.action_cable.worker_pool_size = 4

import * as ActionCable from '@rails/actioncable'

ActionCable.logger.enabled = true

config.action_cable.log_tags = [
  -> request { request.env["user_account_id"] || "no-account" },
  :action_cable,
  -> request { request.uuid }
]

# config/application.rb
class Application < Rails::Application
  config.action_cable.mount_path = "/websocket"
end

# cable/config.ru
require_relative "../config/environment"
Rails.application.eager_load!

run ActionCable.server

$ bundle exec puma -p 28080 cable/config.ru

# config/environments/development.rb
Rails.application.configure do
  config.action_cable.mount_path = nil
  config.action_cable.url = "ws://127.0.0.1:28080" # use wss:// in production
end