Have you used Node.js?

For those of my readers unfamiliar with Node.js, it's a server-side JavaScript framework that provides the ability to create, among other things, network services. To do so, it provides an event loop, which allows for such things as asynchronous processing.

In the PHP ecosystem, a group of Chinese developers have been creating an extension that provides many of the same capabilities as Node.js. This extension, called Swoole, allows you to create web servers with asynchronous capabilities. In many cases, the asynchronous capabilities are handled via coroutines, allowing you to write normal, synchronous code that still benefits from the asynchronous nature of the system event loop, allowing your server to continue responding to new requests as they come in!

We've been gradually adding and refining our Swoole support in Expressive, and recently issued a stable release that will work with any PSR-15 request handler. In this post, I'll enumerate what I feel are the reasons for considering Swoole when deploying your PHP middleware application.

Yesterday, following a unanimous vote from its Core Committee, PHP-FIG formally accepted the proposed PSR-15, HTTP Server Handlers standard.

This new standard defines interfaces for request handlers and middleware. These have enormous potential impact on the PHP ecosystem, as they provide standard mechanisms for writing HTTP-facing, server-side applications. Essentially, they pave the way for developers to create re-usable web components that will work in any application that works with PSR-15 middleware or request handlers!

I faced an interesting question recently with regards to middleware: What happens when we go from a convention-based to a contract-based approach when programming?

Convention-based approaches usually allow for duck-typing; with middleware, it means you can write PHP callables — usually closures — and just expect them to work.

Contract-based approaches use interfaces. I think you can see where this is going.