Matthew Weier O'Phinney has a new post to his site today with a thought about how to make the Zend Framework (both ZF1 & ZF2) easier for developers to get into and use. He suggests that middleware might be the answer.

As I've surveyed the successes and failures of ZF1 and ZF2, I've started considering how we can address usability: how do we make the framework more approachable? One concept I've been researching a ton lately is middleware. Middleware exists in a mature form in Ruby (via Rack), Python (via WSGI), and Node (via Connect / ExpressJS); just about every language has some exemplar. Even PHP has some examples already, in StackPHP and Slim Framework.

[...] The idea is that objects, hashes, or structs representing the HTTP request and HTTP response are passed to a callable, which does something with them. You compose these in a number of ways to build an application.

He gives some examples of current frameworks and libraries that make use of the middleware idea, showing both object and callable methods. He points out that, while middleware is approachable and makes a developer's life easier, it's not something PHP can internally handle. He covers the things a PHP developer would need to access just to get the complete details about a HTTP request and that what's really needed is good HTTP abstraction handling, something the PHP-FIG group has been working on as a part of PSR-7. He includes some examples of how it might be used and where middleware would fit into the picture.

Too often, I feel as PHP developers we focus on the tools we use, and forget that we're working in an HTTP-centric ecosystem. [...] If PSR-7 is ratified, I think we have a strong foot forward towards building framework-agnostic web-focused components that have real re-use capabilities -- not just re-use within our chosen framework fiefdoms.