README

Various helpers that can be used in PHP to simplify event creation and consumption.

This package is meant to be used together with event-consumer re-usable service.

Getting started

In this section you will see how to set up a PHP application to consume and publish events.

Ingress (Event Consumer)

In order to consume events in a PHP application you will need to use event-consumer re-usable service. This service is a node based application which is needed due to the limitations of PHP, long story short, php is not great for long-running tasks, when a PHP process runs for a long time without any restarts there tends to be resource leaks and various other issues that make PHP based consumers unreliable.

In the diagram above you can see what this architecture looks like. The event-consumer service reads messages (events) stored in the SQS queues and sends each consumed message to the events endpoint on your webserver.

Posting event messages over network in this way is a bit strange but this allows us to achieve 2 things that are normally really hard in PHP.

• This puts a webserver (either apache or nginx) in between the event-consumer and our EventHandler, this is the easiest and the most reliable way to achieve "concurrency" in PHP. NOTE There are alternatives approaches e.g. ReactPHP, however, they are not commonly used in the PHP community.

• This avoids long-running processes, each message is handled by a different instance of a PHP process avoiding various issues long-running processes have in PHP.

In your application you will need two things:

• Controller where the events route will be handles

• Psr\Container\ContainerInterface compatible container, this is where you will register any dependencies required by the controller and your EventHandlers

Learn how to set up:

• Events Controller

• Event Handlers

  • Run Action - this event handler can be used to run object that implement Action interface
  • Run Redirect - this event handler can be used to transform event to another event which can then be processed by a different event handler.

Egress (Event Publishing)