rails--rails/actioncable/app/javascript/action_cable/subscription.js

90 lines
2.8 KiB
JavaScript

// A new subscription is created through the ActionCable.Subscriptions instance available on the consumer.
// It provides a number of callbacks and a method for calling remote procedure calls on the corresponding
// Channel instance on the server side.
//
// An example demonstrates the basic functionality:
//
// App.appearance = App.cable.subscriptions.create("AppearanceChannel", {
// connected() {
// // Called once the subscription has been successfully completed
// },
//
// disconnected({ willAttemptReconnect: boolean }) {
// // Called when the client has disconnected with the server.
// // The object will have an `willAttemptReconnect` property which
// // says whether the client has the intention of attempting
// // to reconnect.
// },
//
// appear() {
// this.perform('appear', {appearing_on: this.appearingOn()})
// },
//
// away() {
// this.perform('away')
// },
//
// appearingOn() {
// $('main').data('appearing-on')
// }
// })
//
// The methods #appear and #away forward their intent to the remote AppearanceChannel instance on the server
// by calling the `perform` method with the first parameter being the action (which maps to AppearanceChannel#appear/away).
// The second parameter is a hash that'll get JSON encoded and made available on the server in the data parameter.
//
// This is how the server component would look:
//
// class AppearanceChannel < ApplicationActionCable::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
//
// The "AppearanceChannel" name is automatically mapped between the client-side subscription creation and the server-side Ruby class name.
// The AppearanceChannel#appear/away public methods are exposed automatically to client-side invocation through the perform method.
const extend = function(object, properties) {
if (properties != null) {
for (let key in properties) {
const value = properties[key]
object[key] = value
}
}
return object
}
export default class Subscription {
constructor(consumer, params = {}, mixin) {
this.consumer = consumer
this.identifier = JSON.stringify(params)
extend(this, mixin)
}
// Perform a channel action with the optional data passed as an attribute
perform(action, data = {}) {
data.action = action
return this.send(data)
}
send(data) {
return this.consumer.send({command: "message", identifier: this.identifier, data: JSON.stringify(data)})
}
unsubscribe() {
return this.consumer.subscriptions.remove(this)
}
}