Event Broadcasting

Question 1

What are the current broadcasting drivers supported by Laravel?

Answer 1

Pusher, Redis and a log driver

Question 2

What is the purpose of the log driver?

Answer 2

The log driver is for local development and debugging.

Question 3

Additionally what other driver is available to disable broadcasting?

Answer 3

The “null” driver.

Question 4

Before being able to broadcast any events what service provider needs to be registered in config/app.php file?

Answer 4

BroadcastServiceProvider

Question 5

What is the name of the token required by Laravel Echo for auth?

Answer 5

CSRF Token

Question 6

By default where does Laravel Echo look for the Laravel.csrfToken javascript object?

Answer 6

resources/views/layouts/app.blade.php

Question 7

At the start of a project what command will generate the app.blade.php file?

Answer 7

make:auth Artisan command

Question 8

If you are not using the default layout where would you define the meta tag for CRSF token?

Answer 8

In your applications head HTML element.

Question 9

If your using Pusher to broadcast events what is the prerequisite package required?

Answer 9

pusher/pusher-php-server

Question 10

Where would you config your Pusher credentials?

Answer 10

In the config/broadcasting.php configuration file.

Question 11

What are the additional options provided in the config/broadcastsing.php file?

Answer 11

cluster and encrypted

Question 12

When using Pusher and Laravel Echo where you specify Pusher as your desired broadcaster within resources/assets/js/ ?

Answer 12

bootstrap.js

Question 13

When you are using Redis as broadcaster what composer command would you use to fetch the required library?

Answer 13

composer require predis/predis

Question 14

In order for Redis to work what does it need to be paired with?

Answer 14

A WebSocket server

Question 15

By default where would you include the Socket.IO Javascript client library?

Answer 15

In your applications head HTML element.

Question 16

What is the name of currently maintained Socket.IO server GitHub repository?

Answer 16

tlaverdure/laravel-echo-server

Question 17

Before broadcasting events what will you need to configure and run, helping the response time of your application?

Answer 17

Queue Listener

Question 18

What are the two basic types of channels events can be broadcast over?

Answer 18

public and private

Question 19

What is the difference between public and private channels?

Answer 19

In order for a user to subscribe to a private channel a user must be authenticated and authorized to listen.

Question 20

In order for to broadcast an event what interface is required?

Answer 20

ShouldBroadcast:

class ShippingStatusUpdated implements ShouldBroadcast

Question 21

What is the purpose of the broadcastOn() method?

Answer 21

This method is responsible for returning the channels that the event should broadcast on.

Question 22

Where would we define our channel authorization rules?

Answer 22

routes/channels.php

Question 23

What are the two arguments accepted by the channel method?

Answer 23

the name of the channel and a callback which returns true or false indicating whether the user is authorized to listen on the channel.

Question 24

What do all the authorization callbacks on the channel method receive as the first method?

Answer 24

The currently authenticated user

Question 25

What is the second argument for the authorization callbacks on the channel method?

Answer 25

wildcard parameters

Question 26

By default, what is included when an event that has been broadcast?

Answer 26

public properties

Question 27

Channels within the broadcastOn() method should be instances of?

Answer 27

Channel, PrivateChannel or PresenceChannel

Question 28

Aside of the PrivateChannel what other channel is considered private?

Answer 28

PresenceChannel

Question 29

What is the purpose of the broadcastAs() method?

Answer 29

You may customize the broadcast name by defining a broadcastAs method on the event:

public function broadcastAs()
{
return ‘server.created’;
}

Question 30

What is the purpose of the broadcastWith() method?

Answer 30

This method should return the array of data that you wish to broadcast as the event payload:

public function broadcastWith()
{
return [‘id’ => $this->user->id];
}

Question 31

What is the purpose of the broadcastQueue propertie?

Answer 31

You may customize the queue used by the broadcaster by defining a broadcastQueue property on your event class. This property should specify the name of the queue you wish to use when broadcasting:

public $broadcastQueue = ‘your-queue-name’;

Question 32

What is the purpose of the Broadcast::routes method?

Answer 32

In the BroadcastServiceProvider included with your Laravel application, you will see a call to the Broadcast::routes method. This method will register the /broadcasting/auth route to handle authorization requests

Question 33

Where will the Broadcast::routes automatically place its routes?

Answer 33

web middleware group

Question 34

What would you pass to to customize the assigned attributes on the Broadcast::routes method?

Answer 34

You may pass an array of route attributes to the method if you would like to customize the assigned attributes:

Broadcast::routes($attributes);

Question 35

What method is used to register channel authorization callbacks within routes/channels.php?

Answer 35

Broadcast::channel

Question 36

Like HTTP routes, channel routes may also take advantage of what types of binding?

Answer 36

implicit and explicit route model binding

For example, instead of receiving the string or numeric order ID, you may request an actual Order model instance:

use App\Order;

Broadcast::channel(‘order.{order}’, function ($user, Order $order) {
return $user->id === $order->user_id;
});

Question 37

When building an application that utilizes event broadcasting what may you substitute with the event function?

Answer 37

broadcast function

broadcast(new ShippingStatusUpdated($update));

instead of

event(new ShippingStatusUpdated($update));

Question 38

What is the purpose of the toOthers() method?

Answer 38

The toOthers method allows you to exclude the current user from the broadcast’s recipients:

broadcast(new ShippingStatusUpdated($update))->toOthers();

Question 39

What is the purpose of the leave() method?

Answer 39

To leave a channel, you may call the leave method on your Echo instance:

Echo.leave(‘orders’);

Question 40

What is the purpose of the listen() method?

Answer 40

The listen method listens for a specified event:

Echo.channel(‘orders’)
.listen(‘OrderShipped’, (e) => {
console.log(e.order.name);
});

Question 41

Laravel Echo will automatically assume the events are located in which namespace?

Answer 41

App\Events

Question 42

To configure the route namespace when you instantiate Echo what would you pass as an configuration option?

Answer 42

namespace:

window.Echo = new Echo({
broadcaster: ‘pusher’,
key: ‘your-pusher-key’,
namespace: ‘App.Other.Namespace’
});

Question 43

What is the alternative then passing a namespace configuration option when you instantiate Echo?

Answer 43

Alternatively, you may prefix event classes with a . when subscribing to them using Echo. This will allow you to always specify the fully-qualified class name:

Echo.channel('orders')
    .listen('.Namespace.Event.Class', (e) => {
        //
    });

Question 44

What is the purpose of Presence Channels?

Answer 44

Presence channels build on the security of private channels while exposing the additional feature of awareness of who is subscribed to the channel.

Question 45

If a user is not authorized to join a presence channel what must be returned from the callback?

Answer 45

false or null

Question 46

What are the presence channel Echo methods available?

Answer 46

join, here, joining, leaving and listen

Question 47

What is the purpose of the Echo here() method?

Answer 47

The here callback will be executed immediately once the channel is joined successfully, and will receive an array containing the user information for all of the other users currently subscribed to the channel.

Question 48

What is the purpose of the Echo joining() method?

Answer 48

The joining method will be executed when a new user joins a channel.

Question 49

What is the purpose of the Echo leaving() method?

Answer 49

The leaving method will be executed when a user leaves the channel.

Question 50

What is the purpose of the Echo whisper() method?

Answer 50

Sometimes you may wish to broadcast an event to other connected clients without hitting your Laravel application at all. This can be particularly useful for things like “typing” notifications, where you want to alert users of your application that another user is typing a message on a given screen. To broadcast client events, you may use Echo’s whisper method:

Echo.channel(‘chat’)
.whisper(‘typing’, {
name: this.user.name
});

Question 51

What is the purpose of the Echo listenForWhisper() method?

Answer 51

To listen for client events, you may use the listenForWhisper method:

Echo.channel(‘chat’)
.listenForWhisper(‘typing’, (e) => {
console.log(e.name);
});