Command Pipeline

An in-memory Command Pipeline implementation for PHP. A command pipeline handles cross-cutting concerns in a CQRS application that works with command objects, such as validation of commands, authorization, logging, etc.

Commands are processed in a linear process. The return value of each stage is passed to the next. A stage can only prevent the next stage from being executed by throwing an exception.

The concept of the command pipeline is loosely based on the Pipes and Filters pattern.

Features

• Command validation
• Command authorization
• Wrapping command handling in a Doctrine database transaction
• Dispatching emitted domain events to an event bus

Installation

composer require nicwortel/command-pipeline

If you are using Symfony, enable the CommandPipelineBundle:

// config/bundles.php

return [
    // ...
    NicWortel\CommandPipeline\Bundle\CommandPipelineBundle::class => ['all' => true],
];

Usage

Fetch the command_pipeline service from the service container or (recommended) inject the CommandPipeline into your application code:

<?php

declare(strict_types=1);

use NicWortel\CommandPipeline\CommandPipeline;
// ...

class MyController
{
    private CommandPipeline $commandPipeline;

    public function __construct(CommandPipeline $commandPipeline)
    {
        $this->commandPipeline = $commandPipeline;
    }

    public function saveAction(): Response
    {
        $command = new MyCommand();
        $command->foo = 'bar';

        $this->commandPipeline->process($command);

        // ...
    }
}