README

This package provides an observer for the Laravel Nats push-based event system that uses Laravel events. it uses https://github.com/basis-company/nats.php for using Nats in php

Installation

You can install the package via Composer:

composer require seddighi78/laravel-nats

The package will automatically register itself.

You can optionally publish the config file with:

php artisan vendor:publish --provider="Seddighi78\LaravelNats\NatsServiceProvider" 

Connection

You should set the config env parameters to connect to your NATS server. for example :

NATS_HOST=localhost
NATS_PORT=4222

other configuration parameters can be found in config/nats.php.

Usage

You need to run this command to subscribe to a subject and receive messages from the NATS server, it will dispatch a MessageReceived.php event when a new message is received and then you can listen to this event to do your job.

php artisan nats:subscriber:work {subject} {group?} {--connection=}

Arguments:

• {subject}: The name of your queue or stream (example: main)
• {group?}: (Optional) The consumer group name for the subscription. When specified, it enables NATS Queue Groups functionality.
• {--connection}: (Optional) The connection name to use.

About NATS Queue Groups

When you specify a group name, the subscriber becomes part of a queue group in NATS. Queue groups allow you to distribute messages across multiple subscribers for load balancing. Here's how it works:

• Without a group: Each subscriber receives a copy of every message (pub/sub pattern)
• With a group: Messages are distributed across subscribers in the same group (queue pattern)

Example usage:

# Start subscriber in a queue group named 'workers'
php artisan nats:subscriber:work orders workers

# Start multiple instances to distribute the load
php artisan nats:subscriber:work orders workers # Instance 1
php artisan nats:subscriber:work orders workers # Instance 2

In the example above, if you have multiple subscribers with the same group name, only one subscriber in the group will receive each message, enabling load balancing across your subscribers.

Example

These files are examples of using the package:

Subscribe

Create a listener and listen to the MessageReceived event:

namespace App\Listeners;

use Seddighi78\LaravelNats\Events\MessageReceived;

class PrintOnNatsMessageReceivedListener
{
    public function handle(MessageReceived $event): void
    {
        echo $event->message; // you can process the message here
    }
}

add the listener to EventServiceProvider

use Seddighi78\LaravelNats\Events\MessageReceived;
use App\Listeners\PrintOnNatsMessageReceivedListener;

class EventServiceProvider extends ServiceProvider
{
    protected $listen = [
        MessageReceived::class => [
            PrintOnNatsMessageReceivedListener::class,
        ]
    ];
}

Publish

You can use this code to publish a message on a specific subject:

$client = app(\Seddighi78\LaravelNats\Factories\NatsClientFactoryInterface::class)->getClient();
$client->publish('main', 'test');

When a message is published and the command nats:subscriber:work is running, the MessageReceived event will be dispatched, and you can listen to this event to do your job.

Also you can use the facade for calling these methods:

use Seddighi78\LaravelNats\Facades\Nats;

// calling publish method 
Nats::getClient()->publish('main', 'test');