Installation

The installation of this library can be done with Composer:

composer require aplus/routing

Introduction

The Routing Library makes it possible to route a URL to a particular class method or Closure, with named routes.

The Router is responsible for handling the various Routes of an application, created in a Route Collection.

Let's look at a complete example of the routing system:

use Framework\HTTP\Request;
use Framework\HTTP\Response;
use Framework\Routing\RouteCollection;
use Framework\Routing\Router;

$request = new Request();
$response = new Response($request);
$router = new Router($response);

// Defines a Route Collection for the "http://domain.tld" origin
$router->serve('http://domain.tld', function (RouteCollection $routes) {
    // Route "/" path to App\Controllers\Home::index method on GET requests
    $routes->get('/', 'App\Controllers\Home::index');
    // Route "/contact" path to App\Controllers\Contact::index method on GET requests
    $routes->get('/contact', 'App\Controllers\Contact::index');
    // Route "/contact" path to App\Controllers\Contact::create method on POST requests
    $routes->post('/contact', 'App\Controllers\Contact::create');
});

// Match the Route according to HTTP URL and method
$route = $router->match();

// Run the Route, calling a class method or a Closure and return the Response
$response = $route->run();

// Send the HTTP Response
$response->send();

Placeholders

A path can take placeholders to make it dynamic. So that /users/1 is within /users/{int}.

The available placeholders are:

You can also add custom placeholders. Let's look at an example for the {username} placeholder:

$router->addPlaceholder('username', '([a-z\\d](?:[a-z\\d]|-(?=[a-z\\d])){0,16})');

Actions

The router delivers route actions which can be a Closure or a instance of the Framework\Routing\RouteActions class.

Let's see how to define a Closure for the path /posts/{int}.

In the first argument it receives an array with the values received in the placeholders.

If the path /posts/25 is accessed, the variable $pathArgs[0] will have the number 25, as a string.

In the $constructorArguments parameters, the instances passed in the run method of the matched Route will be received.

Closure:

$routes->get(
    '/posts/{int}',
    function(array $pathArgs, mixed ...$constructorArguments) {
        echo 'Post id is: ' . $pathArgs[0];
        var_dump($constructorArguments);
    }
);

Actions can also be defined as strings. Following the format below:

Class::method/arguments

The Class must extend the Framework\Routing\RouteActions class and have the action method.

The arguments start with the dollar sign and then have numbers that are separated by slashes after the method name.

The number of arguments starts at zero and can have custom order. These are the arguments that will go to the action class method.

$routes->get('/posts/{int}', 'Posts::show/$0');

Let's see an example creating the Posts class, which will have the show method, which will receive two arguments. In the first will be the value of placeholder {int} and in the second will be the value of {slug}:

$routes->get('/categories/{slug}/posts/{int}/', 'Posts::show/$1/$0');

Let's see the class that serves this route:

use Framework\Routing\RouteActions;

class Posts extends RouteActions
{
    protected array $constructorArguments;

    public function __constructor(mixed ...$constructorArguments)
    {
        $this->constructorArguments = $constructorArguments;
    }

    public function show(int $id, string $category)
    {
        echo 'Category slug is: ' . $category;
        echo 'Post id is: ' . $id;
        var_dump($this->constructorArguments);
    }
}

If you do not want to pass the arguments through numbers, with a defined order, you can use the asterisk character to indicate that all placeholder values must go to the method in the order they are received:

$routes->get('/categories/{slug}/posts/{int}/', 'Posts::show/*');

Note that the show method will receive {slug} in the first argument and {int} in the second:

@@ -3,4 +3,4 @@
     class Posts extends RouteActions
     {
-       public function show(int $id, string $category)
+       public function show(string $category, int $id)
        {
            echo 'Category slug is: ' . $category;
            echo 'Post id is: ' . $id;
            var_dump($this->constructorArguments);
        }
     }

To avoid passing arguments to action methods, just do not add the suffix of slashes with numbers or the asterisk:

$routes->get('/categories/{slug}/posts/{int}/', 'Posts::show');

Route Collection

The RouteCollection has several methods for creating Routes.

Most receive the name of the HTTP method to which the Route is assigned.

For example, the HTTP GET method has the get method. The POST, post, etc.

Let's see below an example in which the routing will only receive URLs that start with the origin http://domain.tld and in it, will have a collection of routes for the various HTTP verbs.

In the third parameter of the serve method, an argument with the name of the collection is accepted, which will be prefixed to the name of the routes:

$router->serve('http://domain.tld', function (RouteCollection $routes) {

    // Named route "collection-name.home"
    $routes->get('/', 'App\Controllers\Home::index', 'home');
    
    // Route with Closure instead of class method, and "collection-name.test" as name
    $routes->get('/test', function () {
        return 'Hello world!';
    }, 'test');

    // Different HTTP Methods using placeholders
    $routes->get('/user', 'App\Users::index');
    $routes->post('/user', 'App\Users::create');
    $routes->get('/user/{int}', 'App\Users::show/$0');
    $routes->patch('/user/{username}', 'App\Users::update/$0');
    $routes->put('/user/{int}', [\App\Users::class, 'replace']);
    $routes->delete('/user/{int}', 'App\Users::delete/*');

}, 'collection-name');

$routes->resource('/users', 'App\Users', 'users');

$routes->presenter('/users', 'App\Users', 'users');

$routes->group('/blog', [
    // Route for "/blog/"
    $routes->get('/', 'App\Blog\Posts::index'),
    // Route for "/blog/{title}"
    $routes->get('/{title}', 'App\Blog\Posts::show/$0'),
]);

$routes->group('/blog', [
    // Route for "/blog/"
    $routes->get('/', 'App\Blog\Posts::index'),
    $routes->group('/posts', [
        // Route for "/blog/posts/"
        $routes->get('/', 'App\Blog\Posts::index'),
        // Route for "/blog/posts/{title}"
        $routes->get('/{title}','App\Blog\Posts::show/$0'),
    ]),
]);

$routes->namespace('App\Controllers',[
    // Routes "/user" for App\Controllers\Users::index
    $routes->get('/user', 'Users::index'),
    $routes->namespace('Blog', [
        $routes->group('/blog', [
            // Routes "/blog/posts" for App\Controllers\Blog\Posts::index
            $routes->get('/posts', 'Posts::index'),
            // Routes "/blog/posts/{title}" for App\Controllers\Blog\Posts::show/$0
            $routes->get('/posts/{title}', 'Posts::show/$0'),
        ]),
    ]), 
]);

$routes->notFound(function () {
    return '<h1>Error 404</h1>';
});

$routes->notFound('App\Controllers\Errors::notFound');

Routes

Through routes it is possible to build URLs that point to your RouteCollection:

$route = $router->getNamedRoute('blog');
echo $route->getUrl();

use Framework\HTTP\Request;
use Framework\HTTP\Response;
use Framework\Routing\RouteActions;
use Framework\Routing\RouteCollection;
use Framework\Routing\Router;

class Admin extends RouteActions
{
    protected Request $request;
    protected Response $response;
    protected Router $router;

    public function __construct(
        Request $request,
        Response $response,
        Router $router
    ) {
        $this->request = $request;
        $this->response = $response;
        $this->router = $router;
        session_start();
    }

    protected function beforeAction(string $method, array $arguments) : mixed
    {
        if(!isset($_SESSION['user_id'])) {
            return $this->response->redirect(
                $this->router->getNamedRoute('access.login')->getUrl()
            );
        }
        return null;
    }
    
    public function index()
    {
        echo 'Welcome, ' . $_SESSION['username'] . '!' ;
    }

    public function something($arg0, $arg1)
    {
        vard_dump($arg0, $arg1);
    }
}

$request = new Request();
$response = new Response($request);
$router = new Router($response);

$router->serve(null, function(RouteCollection $routes) {
    $routes->get('admin', 'Admin::index');
    $routes->get('foo/other', 'Admin::something/$1/$0');
    $routes->get('login', 'Access\Login::index', 'access.login');
});

$route = $router->match();

// Run the Route, passing the Request, Response and Router instances
// to the RouteActions constructor,
// or, if the action is as Closure; to its parameters
$response = $route->run($request, $response, $router);

$response->send();

Router

The router is where the RouteCollections are stored, and it decides which Route will run according to the HTTP Request method and URL.

It is possible to serve several RouteCollections that will respond through an URL Origin.

In the example below, a collection of routes for both http and https as a scheme is served.

Below is a collection for https://api.domain.tld. Note that it will only work for https and has a prefix name for the route name called api, defined in the third parameter:

$router->serve('{scheme}://domain.tld', function (RouteCollection $routes) {
    // Routes ...
})->serve('https://api.domain.tld', function (RouteCollection $routes) {
    // Routes ...
}, 'api');

$router->setDefaultRouteNotFound('App\Errors::notFound');

$route = $router->getNamedRoute('api.users.followers');

$route = $router->getMatchedRoute();

$router->setAutoOptions();

$router->setAutoMethods();

Conclusion

Aplus Routing Library is an easy-to-use tool for, beginners and experienced, PHP developers.
It is perfect for routing URLs to Closures or class methods very quickly.
The more you use it, the more you will learn.