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Front Controller 

What is the purpose of a front controller in PHP?
How does the front controller associate URL paths?

Single Entry Application

A single entry PHP script is called front controller design pattern. Let's add another page that says goodbye. 
 
/*
    front_controller/public/front.php - Single Entry Application

    Request::getPathInfo() returns the front controller script name.
    $map associates URL paths with their corresponding PHP script paths.

    cd github/php-pages/main/framework/front_controller/
    composer require symfony/http-foundation
    php -S localhost:8000 public/front.php

    http://localhost:8000/hello     # Hello World
    http://localhost:8000/bye       # Goodbye!
    http://localhost:8000/front.php # Page not found
*/

ini_set('display_errors', 1);
require_once __DIR__.'/../vendor/autoload.php';

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

$request = Request::createFromGlobals();
$response = new Response();

$map = [
    '/hello' => __DIR__ . '/../src/pages/hello.phtml',
    '/goodby' => __DIR__ . '/../src/pages/goodby.phtml',
];

$path = $request->getPathInfo();

if (isset($map[$path])) {
    ob_start();
    
    require($map[$path]);
    $response->setContent(ob_get_clean()); // Look here
    
} else {
    $response->setStatusCode(404);
    $response->setContent("Page not found");
}

$response->send();

View Template

The hello.phtml script can now be converted to a template. 
 
Hello <?= htmlspecialchars(
    $request->get('name', 'World'), ENT_QUOTES, 'UTF-8');
?>

Vanilla PHP

Here's how the provided example could be rewritten using plain PHP. 
 
ini_set('display_errors', 1);

$map = [
    '/hello' => __DIR__ . '/../src/pages/hello.phtml',
    '/goodby' => __DIR__ . '/../src/pages/goodby.phtml',
];

// Manually fetching the requested path
$path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

if (isset($map[$path])) {
    ob_start();
    
    include($map[$path]);
    $content = ob_get_clean(); // Capture the output of the included file
    
    // Setting the response content
    echo $content;
} else {
    // Handling a 404 not found
    header("HTTP/1.0 404 Not Found");
    echo "Page not found - Vanilla PHP";
}

Apache Httpd

With httpd server we can use htaccess to always access front.php. 
  
RewriteEngine on
RewriteBase /php/framework/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ front.php [L,QSA]



  Last update: 67 days ago