laravel - The basics of php routing

Question

I'm looking for a tutorial or explaination on how to do very basic php routing.

For example when I visit a link like: mywebsite.com/users I want to run the get method of a route class to provide the data, in the same way laravel does it.

Route::get('users', function()
{
    return 'Users!';
});

Can somebody explain how to do this or provide me with some more information?

Answer 1

In its most common configuration, PHP relies on the web server to do the routing. This is done by mapping the request path to a file: If you request www.example.org/test.php, the web server will actually look for a file named test.php in a pre-defined directory.

There is a feature that comes in handy for our purpose: Many web servers also allow you to call www.example.org/test.php/hello and it will still execute test.php. PHP makes the additional stuff in the requested path accessible via the $_SERVER['PATH_INFO'] variable. In this case it would contain "/hello".

Using this, we can build a very simple router like this:

<?php

// First, let's define our list of routes.
// We could put this in a different file and include it in order to separate
// logic and configuration.
$routes = array(
    '/'      => 'Welcome! This is the main page.',
    '/hello' => 'Hello, World!',
    '/users' => 'Users!'
);

// This is our router.
function router($routes)
{
    // Iterate through a given list of routes.
    foreach ($routes as $path => $content) {
        if ($path == $_SERVER['PATH_INFO']) {
            // If the path matches, display its contents and stop the router.
            echo $content;
            return;
        }
    }

    // This can only be reached if none of the routes matched the path.
    echo 'Sorry! Page not found';
}

// Execute the router with our list of routes.
router($routes);

?>

For the sake of simplicity, I did not make the router a class. But from here on, that shouldn't be a problem either.

Let's assume we named this file index.php. We can now call www.example.org/index.php/hello to get a nice "Hello, World!" message. Or www.example.org/index.php/ to get the main page.

The "index.php" in that URL is still ugly, but we can fix this by using URL rewriting. In Apache HTTPD you would put a .htaccess file in the same directory with the following content:

RewriteEngine on
RewriteRule ^(.*)$ index.php/$1

And there you are! Your very own router with under 10 lines of logic code (not counting comments and the routes list).