Now that we have installed the library, verified its dependencies and created an ActionCable Channel in our app, it's time to actually make the magic happen.

You can send CableReady broadcasts from just about anywhere in your application: ActiveJobs, controller actions, ActiveRecord model callbacks, rake tasks, pub/sub workers, webhooks, you name it.

We're going to use an ActiveRecord after_create callback to demonstrate welcoming a new user.

Broadcasting operations

There are three distinct aspects of every CableReady invocation:

1. Channel stream identifier(s): decide who (or what) will receive operations

2. Operation queueing: define one or more operations to broadcast

3. Broadcast: broadcast all queued operations immediately

class User < ApplicationRecord
  include CableReady::Broadcaster
​
  after_create do
    cable_ready["visitors"].console_log(message: "Welcome #{self.name} to the site!")
    cable_ready.broadcast # send queued console_log operation to all ExampleChannel subscribers
  end
end

The ExampleChannel that we created in the Setup will send any operations broadcast to visitors to all currently subscribed clients. In the code above, everyone on the site will see a Console Log message welcoming the latest member.

On the Working with CableReady page, we'll see how we can set up CableReady so that you can access it from anywhere in your application, so that you don't have to include the module in every class.

You can call cable_ready multiple times to add more operations to the queue. Since cable_ready is a singleton instance, you can continue to add operations to the queue even across multiple methods, or a recursive function.

You can use different operations together, and each operation can have completely different arguments. Without a call to broadcast, operations will accumulate for the specified Channel stream identifier.

cable_ready["visitors"].console_log(message: "We have more salad than we can eat.")
cable_ready["visitors"].set_style(selector: "body", name: "color", value: "red")
cable_ready["visitors"].set_style(selector: "#foo", name: "color", value: "blue")

Method chaining

When you call cable_ready["visitors"] you are presented with a CableReady::Channels object, which supports method chaining. This is a fancy way of saying that you can link up as many operations in sequence as you want, and they will ultimately be broadcast in the order that they were created.

cable_ready["visitors"].console_log(message: "1").console_log(message: "2")

The broadcast method can conclude the chain, meaning that you can send a console message to everyone looking at your site with:

cable_ready["visitors"].console_log(message: "Welcome!").broadcast