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Diffstat (limited to 'actioncable/README.md')
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1 files changed, 115 insertions, 25 deletions
diff --git a/actioncable/README.md b/actioncable/README.md index fe4d213485..44fb81478d 100644 --- a/actioncable/README.md +++ b/actioncable/README.md @@ -7,7 +7,6 @@ and scalable. It's a full-stack offering that provides both a client-side JavaScript framework and a server-side Ruby framework. You have access to your full domain model written with Active Record or your ORM of choice. - ## Terminology A single Action Cable server can handle multiple connection instances. It has one @@ -52,10 +51,10 @@ module ApplicationCable self.current_user = find_verified_user end - protected + private def find_verified_user - if current_user = User.find_by(id: cookies.signed[:user_id]) - current_user + if verified_user = User.find_by(id: cookies.encrypted[:user_id]) + verified_user else reject_unauthorized_connection end @@ -86,12 +85,17 @@ end The client-side needs to setup a consumer instance of this connection. That's done like so: -```coffeescript -# app/assets/javascripts/cable.coffee -#= require action_cable +```js +// app/assets/javascripts/cable.js +//= require action_cable +//= require_self +//= require_tree ./channels -@App = {} -App.cable = ActionCable.createConsumer("ws://cable.example.com") +(function() { + this.App || (this.App = {}); + + App.cable = ActionCable.createConsumer("ws://cable.example.com"); +}).call(this); ``` The `ws://cable.example.com` address must point to your Action Cable server(s), and it @@ -163,7 +167,7 @@ App.cable.subscriptions.create "AppearanceChannel", buttonSelector = "[data-behavior~=appear_away]" install: -> - $(document).on "page:change.appearance", => + $(document).on "turbolinks:load.appearance", => @appear() $(document).on "click.appearance", buttonSelector, => @@ -293,8 +297,7 @@ The rebroadcast will be received by all connected clients, _including_ the clien ### More complete examples -See the [rails/actioncable-examples](http://github.com/rails/actioncable-examples) repository for a full example of how to setup Action Cable in a Rails app, and how to add channels. - +See the [rails/actioncable-examples](https://github.com/rails/actioncable-examples) repository for a full example of how to setup Action Cable in a Rails app, and how to add channels. ## Configuration @@ -323,7 +326,10 @@ Rails.application.paths.add "config/cable", with: "somewhere/else/cable.yml" ### Allowed Request Origins -Action Cable will only accept requests from specified origins, which are passed to the server config as an array. The origins can be instances of strings or regular expressions, against which a check for match will be performed. +Action Cable will only accept requests from specific origins. + +By default, only an origin matching the cable server itself will be permitted. +Additional origins can be specified using strings or regular expressions, provided in an array. ```ruby Rails.application.config.action_cable.allowed_request_origins = ['http://rubyonrails.com', /http:\/\/ruby.*/] @@ -331,12 +337,19 @@ Rails.application.config.action_cable.allowed_request_origins = ['http://rubyonr When running in the development environment, this defaults to "http://localhost:3000". -To disable and allow requests from any origin: +To disable protection and allow requests from any origin: ```ruby Rails.application.config.action_cable.disable_request_forgery_protection = true ``` +To disable automatic access for same-origin requests, and strictly allow +only the configured origins: + +```ruby +Rails.application.config.action_cable.allow_same_origin_as_host = false +``` + ### Consumer Configuration Once you have decided how to run your cable server (see below), you must provide the server URL (or path) to your client-side setup. @@ -373,11 +386,11 @@ App.cable = ActionCable.createConsumer() ### Other Configurations -The other common option to configure is the log tags applied to the per-connection logger. Here's close to what we're using in Basecamp: +The other common option to configure is the log tags applied to the per-connection logger. Here's an example that uses the user account id if available, else "no-account" while tagging: ```ruby -Rails.application.config.action_cable.log_tags = [ - -> request { request.env['bc.account_id'] || "no-account" }, +config.action_cable.log_tags = [ + -> request { request.env['user_account_id'] || "no-account" }, :action_cable, -> request { request.uuid } ] @@ -385,7 +398,7 @@ Rails.application.config.action_cable.log_tags = [ For a full list of all configuration options, see the `ActionCable::Server::Configuration` class. -Also note that your server must provide at least the same number of database connections as you have workers. The default worker pool is set to 100, so that means you have to make at least that available. You can change that in `config/database.yml` through the `pool` attribute. +Also note that your server must provide at least the same number of database connections as you have workers. The default worker pool is set to 4, so that means you have to make at least that available. You can change that in `config/database.yml` through the `pool` attribute. ## Running the cable server @@ -396,14 +409,14 @@ application. The recommended basic setup is as follows: ```ruby # cable/config.ru -require ::File.expand_path('../../config/environment', __FILE__) +require_relative '../config/environment' Rails.application.eager_load! run ActionCable.server ``` Then you start the server using a binstub in bin/cable ala: -``` +```sh #!/bin/bash bundle exec puma -p 28080 cable/config.ru ``` @@ -425,7 +438,7 @@ For every instance of your server you create and for every worker your server sp ### Notes -Beware that currently the cable server will _not_ auto-reload any changes in the framework. As we've discussed, long-running cable connections mean long-running objects. We don't yet have a way of reloading the classes of those objects in a safe manner. So when you change your channels, or the model your channels use, you must restart the cable server. +Beware that currently, the cable server will _not_ auto-reload any changes in the framework. As we've discussed, long-running cable connections mean long-running objects. We don't yet have a way of reloading the classes of those objects in a safe manner. So when you change your channels, or the model your channels use, you must restart the cable server. We'll get all this abstracted properly when the framework is integrated into Rails. @@ -433,7 +446,7 @@ The WebSocket server doesn't have access to the session, but it has access to th ## Dependencies -Action Cable provides a subscription adapter interface to process its pubsub internals. By default, asynchronous, inline, PostgreSQL, evented Redis, and non-evented Redis adapters are included. The default adapter in new Rails applications is the asynchronous (`async`) adapter. To create your own adapter, you can look at `ActionCable::SubscriptionAdapter::Base` for all methods that must be implemented, and any of the adapters included within Action Cable as example implementations. +Action Cable provides a subscription adapter interface to process its pubsub internals. By default, asynchronous, inline, PostgreSQL, and Redis adapters are included. The default adapter in new Rails applications is the asynchronous (`async`) adapter. To create your own adapter, you can look at `ActionCable::SubscriptionAdapter::Base` for all methods that must be implemented, and any of the adapters included within Action Cable as example implementations. The Ruby side of things is built on top of [websocket-driver](https://github.com/faye/websocket-driver-ruby), [nio4r](https://github.com/celluloid/nio4r), and [concurrent-ruby](https://github.com/ruby-concurrency/concurrent-ruby). @@ -441,9 +454,9 @@ The Ruby side of things is built on top of [websocket-driver](https://github.com ## Deployment Action Cable is powered by a combination of WebSockets and threads. All of the -connection management is handled internally by utilizing Ruby’s native thread +connection management is handled internally by utilizing Ruby's native thread support, which means you can use all your regular Rails models with no problems -as long as you haven’t committed any thread-safety sins. +as long as you haven't committed any thread-safety sins. The Action Cable server does _not_ need to be a multi-threaded application server. This is because Action Cable uses the [Rack socket hijacking API](http://www.rubydoc.info/github/rack/rack/file/SPEC#Hijacking) @@ -455,11 +468,88 @@ with all the popular application servers -- Unicorn, Puma and Passenger. Action Cable does not work with WEBrick, because WEBrick does not support the Rack socket hijacking API. +## Frontend assets + +Action Cable's frontend assets are distributed through two channels: the +official gem and npm package, both titled `actioncable`. + +### Gem usage + +Through the `actioncable` gem, Action Cable's frontend assets are +available through the Rails Asset Pipeline. Create a `cable.js` or +`cable.coffee` file (this is automatically done for you with Rails +generators), and then simply require the assets: + +In JavaScript... + +```javascript +//= require action_cable +``` + +... and in CoffeeScript: + +```coffeescript +#= require action_cable +``` + +### npm usage + +In addition to being available through the `actioncable` gem, Action Cable's +frontend JS assets are also bundled in an officially supported npm module, +intended for usage in standalone frontend applications that communicate with a +Rails application. A common use case for this could be if you have a decoupled +frontend application written in React, Ember.js, etc. and want to add real-time +WebSocket functionality. + +### Installation + +``` +npm install actioncable --save +``` + +### Usage + +The `ActionCable` constant is available as a `require`-able module, so +you only have to require the package to gain access to the API that is +provided. + +In JavaScript... + +```javascript +ActionCable = require('actioncable') + +var cable = ActionCable.createConsumer('wss://RAILS-API-PATH.com/cable') + +cable.subscriptions.create('AppearanceChannel', { + // normal channel code goes here... +}); +``` + +and in CoffeeScript... + +```coffeescript +ActionCable = require('actioncable') + +cable = ActionCable.createConsumer('wss://RAILS-API-PATH.com/cable') + +cable.subscriptions.create 'AppearanceChannel', + # normal channel code goes here... +``` + +## Download and Installation + +The latest version of Action Cable can be installed with [RubyGems](#gem-usage), +or with [npm](#npm-usage). + +Source code can be downloaded as part of the Rails project on GitHub + +* https://github.com/rails/rails/tree/master/actioncable + ## License Action Cable is released under the MIT license: -* http://www.opensource.org/licenses/MIT +* https://opensource.org/licenses/MIT ## Support |