Flex

WARNING: This framework is under active development and is not yet ready for use in production.

A simple stack based framework that's easy to use and extend. Flex uses PSR-7 requests and responses, the PSR-11 container, and other community libraries like Fast Route, Zend Diactoros, League Container, and Whoops.

Why Flex?

Flex is a micro framework that stays out of your way and provides a minimal wrapper that allows you to write simple framework agnostic application code. Routing is based on a simple stack of application code whose only interaction with the framework is through PSR-7 request and response object.

Component Replacement

All framework components can be replaced to suit the needs of the application by modifying the dependency injection container that is passed to Flex.

Container

todo

Request & Response

todo

Router

todo

Not Found & Not Allowed Controllers

todo

Error Handler

todo

Writer

todo

Getting Started

Getting started with Flex is as simple as creating an instance of the Flux App and calling the run method. If you don't need to modify the container you can simply call the App::create() method to setup the application with a default container.

<?php

use MattColf\Flex\App;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;

$config = [];
$config['debug'] = true;

$config['routes'] = [
    'index' => [
        'method' => 'GET',
        'path' => '/',
        'stack' => [
            function (ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface
            {
                $response->getBody()->write('<h1>Hello World!</h1>');
               
                return $response;
            }
        ]
    ]
];


$app = App::create($config);
$app->run();

Adding Routes

In Flex, routes are defined through the routes configuration key. Each entry in the routes array represents either a single route or group of routes (more below) where the key is the name of the route and the value is an array of the following route options.

• method: The HTTP method, or methods, that this route should match. Can be a string ('GET') or an array of strings (['GET', 'POST']). Must be a valid HTTP method (GET, POST, etc.).
• path: The relative path that the route should match. Should start with a /, like /homepage.
• stack: An array of middleware and controller references that should be run when the route matches. See Stack Definition below for more details.

Groups

When a group of routes should all have the same path prefix or middleware, you can group those routes to simplify your configuration. Groups are configured the same as routes, but also have the routes option.

• path: The relative path that all routes in this group must start with.
• stack: An array of middleware that should be added to each route in this group. This stack will be run before each member route's stack.
• routes: An array of routes that are part of this group.

Note that groups may not have a method option.

Route Parameters

Route paths may contain parameters. When the application is run, these are provided to the stack as an array in the request object route_params attribute. Parameters are included in the path as a curly bracket wrapped string. Here's an example.

$routes = [
    'user-details' => [
        'method' => 'GET',
        'path' => '/users/{id}',
        'stack' => [
            'user.controller'
        ]
    ]
];

By default, Flex uses the Fast Route router. For more details, review the documentation on how to use route parameters there.

Stack Members

Each route's stack defines what should be run when the route matches. It is made up of references to middleware and controller functions that use PSR-7 request and response objects.

Middleware Function

Each stack may have any number of middleware functions.

function (ServerRequestInterface $request, ResponseInterface $response, callable $next) : ResponseInterface
{
    // your code that should run before the rest of the stack
    
    // you are responsible for calling the next item in the stack
    $response = $next($request, $response);
    
    // your code that shiuld run after the rest of the stack
    
    return $response;
}

Controller Function

Each stack must have a single controller which must also be the last item in the stack.

function (ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface
{
    // your controller code

    return $response;
}

Stack References

Flex uses a reference to lookup each middleware and controller function that you add to the stack. These references are generally either callable functions or keys to invokeavble classes in the dependency injection container, but more types are supported. Here are some examples.

Container Class Invoke

class Controller
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
        return $response;
    };
}

$container->set('controller', new Controller());
$reference = 'controller';

Container Class Method

class Controller
{
    public function run(ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
        return $response;
    };
}

$container->set('controller', new Controller());
$reference = 'controller::run';

Anonymous Function

$reference = function (ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
    return $response;
};

Object Invoke

class Controller
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
        return $response;
    };
}

$reference = [new Controller()];

Object Method Callable

class Controller
{
    public function run(ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
        return $response;
    };
}

$reference = [new Controller(), 'run'];

Static Method Callable

class Controller
{
    public function run(ServerRequestInterface $request, ResponseInterface $response) : ResponseInterface {
        return $response;
    };
}

$reference = [Controller::class, 'run'];

Configuration

The following configuration values are available.

• debug
• routes
• middleware