RabbitMQ RPC message

This package makes ready to use implementation of RabbitMQ RPC tutorial published on: https://www.rabbitmq.com/tutorials/tutorial-six-php.html It implements both server side and client.

Thanks to this package you will be able to send a message to RabbtiMQ, then receive this message (on the server side) handle it and finally send the response to the client (Producer).

Unlike tutorial this package is set to save the queue and messages after RabbtiMQ server reboot.

Installation

Installation of the package by Composer:

composer require tzmudz/rabbitmq_rpc

Package uses an Environment Variables delivered by vlucas/phpdotenv package. You have to create an .env file in the root folder containing variables:

RABBTIMQ_PORT=5672
RABBTIMQ_HOST=localhost
RABBTIMQ_USERNAME=guest
RABBTIMQ_PASSWORD=guest

Thus if you are using e.g. Laravel all you have to do is to put this variables in your .env app file. Notice If your application doesn’t use .env files, don't forget to load them by executing the code:

$dotenv = Dotenv\Dotenv::create(__DIR__);
$dotenv->load();

You can find more information here: https://github.com/vlucas/phpdotenv

Usage

Package comes with two classes: Producer and Consumer.

Producer

The Producer class is responsible for delivering messages to RabbtiMQ. In your application create a new instance of Tzm\Rpc\Producer(). As a parameter you can set the queue name (by default the name is default):

$producer = new Tzm\Rpc\Producer('long_task_queue_name');

Otherwise you can set the queue name by calling the setQueueName().

$producer = new Tzm\Rpc\Producer();
$producer->setQueueName('long_task_queue_name');

Finally you have to call the method call() with message as parameter:

$producer = new Tzm\Rpc\Producer();
$producer->setQueueName('long_task_queue_name')->call($message);

Where $message is a string of data that should be send to the RabbtiMQ server. Actually RPC sends a message and waits for the response given from server. But, if you don't want to wait for server’s response you can use withoutWaiting():

$producet = new Tzm\Rpc\Producer();
$producer->withoutWaiting()->call($message);

Consumer

To process the queued message you need Consumer class. This class is abstract. You have to create a new class that inherits from Consumer abstract class. Then you have to implement several methods.

handleMessage()

This method is responsible for process the message. It accepts $message as a parameter e.g.

public function handleMessage($message)
{
    echo $message;
}

handleError()

Generally it's not necessary, but it handles the error. If the method handleMessage() thrown an error it will be passed to the handleError() method. So that you can handle the error however you want. e.g. in Laravel you can log the error message:

public function handleError(\Exception $e)
{
    Log::error($e->getMessage());
}

setResults()

After the message is handled RabbitMQ returns a response message. Initially it returns true. But if you want you can use setResult() method to set the data you want to return. E.g.:

public function handleMessage($message)
{
    $this->setResult('this_will_be_returned_to_Producer');
}

Run Consumer

Your inherited class of consumer of Consumer should look like this:

namespace Tzm\Rpc;

class EchoMessage extends Consumer
{
    protected function handleMessage($message)
    {
        echo $message;
    }

    protected function handleError(\Exception $e)
    {
        \Log::error($e->getMessage()); // In Laravel Log exception message
    }
}

Then you can run the Consumer:

$consumer = new EchoMessage();
$consumer->run();

Just like a Producer class this one also has a setQueueName() method. So you can set the queue name
when new instance is being created or later by using method.

Console information

Additionally there are two methods:

consoleMessage($req)

It's used to display message in a console. It has one parameter $req - containing all the info about the recievied message. By default this method returns string: New request so if a new message will be delivered the console should print:

[04.11 11:03:49] [NEW] New request
[04.11 11:03:49] [OK] New request

Whole message could be changed by overriding consoleInfo() method. ATTENTION! Don't forget to run Consumer class first (it will create the queue on RabbitMQ server)

License

MIT