Sunday, 30 July 2017

Some thoughts on (Modern) PHP

I have experience in both Java and PHP. Java mostly for traditional desktop apps, embedded UIs and PHP for websites.

Custom PHP frameworks I've built or helped build took into account the way PHP is executed: you are stateless and need to setup everything on every request (runtime is fast to start with FPM and opcode cache). Namespaces based cheap autoloader worked great. We used singletons for getting the configuration and connections to DBs. There was almost no setup code that needed to be run every time other than loading .ini based configuration and connecting to the DB. My webapps responded under 20ms (DB and other services like sphinx included), and I could get it to respond in 1 ms for things where we needed to be quick and didn't have to output HTML with Forms. It was really small and you could read the whole framework code in 1-2 hours. It worked with SQL in a reasonable way. You didn't have to write your SQL for simple CRUD, but for larger things involving joining multiple tables and more complex expressions we wrote native SQL. Caching was done thoughtfully, using  APC user cache (SHM with zero copy). It just felt nice.

I switched jobs recently, and started with Symfony 3. The thing felt like some Java framework, but poorly documented and harder to use than it should be. It had lots and lots of setup code done before handling every request. There's a whole DI framework with it's load of setup code for every component. And you have to do setup even though you don't use the component in that particular request. There are ways of doing setup lazily, but you still waste time to wire that up. Framework overhead can be 30-100ms. Other modern PHP frameworks often have similar overhead. I know that there's PHP-PM, to save some of that work that isn't really $_REQUEST specific, but it doesn't seem to be used much for production. And using Silex (deprecated by Symfony 4?) is really not that different, you still either reuse Symfony components, or rewrite them, but with similar "best practices" that are inspired by Java.

Regarding persistence, Doctrine and it's verbosity feels very ugly to me. I'd much rather use SQL syntax for defining relationships than bunch of PHP with special syntax comments or xml or yaml. And also use real SQL for complex queries.

Everybody is using type hints wherever they can, and it feels as verbose as Java, but without compile time type safety, and you can't really put type information everywhere (class members for example).

So you are almost using a type safe language, but can't get performance or compile time benefits, because inevitably, you'll have to use some dynamic typing or other dynamic language features.

Even though PHP runtime has made great progress with 7.x (it's probably the fastest interpreted language, and it's great it has reference counted garbage collection), it feels like language is struggling to find it's identity, with it taking a lot from Java and still coping with ugly legacy ($, having to use $this inside a class function, php.ini, features for supporting templating even though it's rarely used as a templating language in modern frameworks,

Learning Python and Flask (as an example) was much more enjoyable than switching from a nimble custom PHP framework to Symfony. Using NodeJS and minimalistic components to build my own framework was also nice. I'd love to try GoLang, Swift or Rust in the backend too.

And there's the thing that most of the PHP frameworks try too hard to be full stack, when nowdays it's not rare you only do REST APIs on the backend. So there's a lot of infrastructure and assumptions in place for rendering HTML that you really don't need to use and that gets in the way when learning the framework and is wasteful when the code is executing.

I'd argue you can write fast, simple and maintainable PHP, by using state PHP runtime has setup for you ($_POST, $_GET, $_SERVER etc), namespaces and a namespace based autoloader, trying to use pure functions when you can (using static classes shouldn't be a sin - use it to split your code in sensible parts), and using general good practices for writing readable and maintainable code (avoid long functions, huge classes, too much block nesting, decoupling, naming things in a good way). With some coding conventions you can write a decent and productive framework quickly, but you could do that with a nicer language too, so what's the point?

(Thankfully, I'm not using Symfony on my new job, and Yii2 does suffer from some issues too, it at least feels better for now)

1 comment:

  1. Did you try Laravel framework ? It's way cleaner and intuitive then Symfony ;)