Broadcasting with public channels

Broadcasting with Public Channels

We can dispatch events from the backend to the frontend publicly. For example, when a new product is on sale, we want to notify every user on the website.

Let's generate an event class:

php artisan make:event NewProductOnSaleReleased

This generates a class. Let's apply a few small changes; the final class should be like this:

<?php

namespace App\Events;

use Illuminate\Broadcasting\Channel;
use Illuminate\Broadcasting\InteractsWithSockets;
use Illuminate\Broadcasting\PresenceChannel;
use Illuminate\Broadcasting\PrivateChannel;
use Illuminate\Contracts\Broadcasting\ShouldBroadcastNow;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;

class NewProductOnSaleReleased implements ShouldBroadcastNow
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    public $productName;

    /**
     * Create a new event instance.
     */
    public function __construct(string $productName)
    {
        $this->productName = $productName;
    }

    /**
     * Get the channels the event should broadcast on.
     *
     * @return array<int, \Illuminate\Broadcasting\Channel>
     */
    public function broadcastOn(): array
    {
        return [
            new Channel('product.on.sale'),
        ];
    }
}

Now, on the frontend, add this code to your Blade view.

<script>
    document.addEventListener("DOMContentLoaded", () => {
        Echo.channel('product.on.sale')
            .listen('NewProductOnSaleReleased', (e) => {
                alert('New Product On Sale!!!' + e.productName);
        });
    });
</script>

To trigger this, execute:

App\Events\NewProductOnSaleReleased::dispatch("New Ressonance Sale. If you see this message send a print to support@ressonance.com and you have 3 months for free.")

You should see this message in the browser:

This is an easy example. To understand everything you can do and all broadcasting features, take a look at the Laravel documentation.

The next tutorial will show you a simple private channel.