linkorb/bus

Command Bus component

Command Bus Component

This standalone component implements the Command Pattern., _(*1)

It is inspired by the Laravel illuminate/bus and illuminate/queue components, but aims to be framework agnostic., _(*2)

For more information about the Command Bus Pattern:, _(*3)

• http://en.wikipedia.org/wiki/Command_pattern
• http://sourcemaking.com/design_patterns/command

Usage

Any Command requires two classes: the DoSomethingCommand class and the DoSomethingHandler class., _(*4)

You can instantiate the Command from your controllers when needed, and dispatch it onto the Bus., _(*5)

The Bus will then resolve the matching Handler class, and ask it to handle the new Command., _(*6)

Here's how you use it:, _(*7)

An example Command class:

<?php

use LinkORB\Component\Bus\CommandInterface;

class OrderConfirmCommand implements CommandInterface
{
    private $orderId;
    public function __construct($orderId)
    {
        $this->orderId = $orderId;
    }

    public function getOrderId()
    {
        return $this->orderId;
    }
}

An example Handler class:

<?php

use LinkORB\Component\Bus\HandlerInterface;
use LinkORB\Component\Bus\CommandInterface;

class OrderConfirmHandler implements HandlerInterface
{
    private $db;
    private $mailer;

    // the constructor automatically receives requested services from the container
    public function __construct($db, $mailer)
    {
        $this->db = $db;
        $this->mailer = $mailer;
    }

    // this method is called by the bus to handle commands
    public function handle(CommandInterface $command)
    {
        $order = $this->db->fetchOneById('orders', $command->getOrderId());
        $this->mailer->mail($order['email'], "Thanks for your order, " . $order['customername']);

    }
}

Setting up the bus in your init script

use LinkORB\Component\Bus\Bus;

// Reuse an existing container, or create a plain php array
// Any array type dependency injection container will work too (symfony, pimple, etc)
$container = array(
    'db'=>$db,
    'mailer'=>$mailer
);

// Instantiate the bus, and optionally pass a container
$bus = new Bus($container);

// now add the bus to the container, or use any other method to pass the bus to your controllers

Using the bus in your Controllers:

class basketController
{
    public function confirmAction()
    {
        $orderid = 5;

        // Instantiate a Command
        $command = new OrderConfirmCommand($orderid);

        // Dispatch the command
        $this->bus->dispatch($command);
    }
}

Calling commands from the command-line

A simple command-line dispatcher is included. It can be used like this:, _(*8)

./vendor/bin/bus bus:dispatch "Acme\Bus\DoSomethingCommand" -p color="red" -g os="linux"

The -p arguments will be passed as parameters to the command. You can pass as many as you want. The -g arguments will be inserted into a simple array "container", so it can be used by the Handlers, _(*9)

One example command is included:, _(*10)

./vendor/bin/bus bus:dispatch "LinkORB\Component\Bus\Bus\HelloCommand" -p name="World" -g sender="me"

This will output:, _(*11)

Hello, World from me!

License

MIT (see LICENSE.md), _(*12)

Brought to you by the LinkORB Engineering team

Check out our other projects at linkorb.com/engineering., _(*13)

Btw, we're hiring!, _(*14)