Simple Autoload class and include example

Question

Ok im trying to get my head around autoload and i am a bit confused, i read a bunch of posts and now i think i am more confused, if i had a simple example i think i could get my head around it.

So lets say i have this simple project:

var/www/myproject/index.php

Then i have var/www/myproject/classes/database.php with this:

class Database {
    function __construct() {
        echo 'This is my Database Class <br />';
    }
}

And also var/www/myproject/classes/functions.php with this:

class Functions {
      function __construct() {
          echo 'This is my functions class <br />';
      } 
}

And also var/www/myproject/classes/users.php with this:

class Users {
      function __construct() {
          echo 'This is my user class <br />';
      } 
}

Then lets assume i have 2 includes here:

var/www/myproject/includes/header.php

var/www/myproject/includes/footer.php

So how would i autoload all those files and classes. Im thinking something like this but the examples i come across seem very specific to their setup or only apply to one folder, or include namespace which i haven't grasped.

I was thinking my index might look something like this:

function __autoload($class_name) {
    require_once 'classes/'.$class_name . '.php';
}

But then that wouldn't work for includes for header and footer so maybe something like this is more appropriate

$path = array('classes/','includes/');
foreach ($path as $directory) {
    if (file_exists($directory . ? . '.php')) {
        require_once ($directory . ? . '.php');
    }

The idea being that it would include everything in the directory it finds but i am not sure how to do it, the ? was supposed to represent a wildcard and i understand this wont work, im trying to give an example of what im trying to do.

This must be something people come across a lot and im sure there is a good solution, just cant find an article that explains it well enough for me to understand

Answer 1

If you use in your project namespaces i would recommend to use simple code:

 class ClassLoader {

      public  function handle($class) {
         $file = str_replace('\\', '/', $class.'.php');
         if(!file_exists($file)){
             throw new \Exception('class '.$class.' file not exists');
         }
         include_once $file;
     }

 }

 $autloader = new Classes\ClassLoader;
 spl_autoload_register(array($autloader, 'handle'));

// from now you can load all Classes from directories specified in namespace of class for example

 /////////////////////////////////////////////
 // directory => framework/classes/User.php //
 /////////////////////////////////////////////

 namespace framework\classes;
 class User {
     public function helloWorld(){
             echo 'hello World';
     }
 }

 //////////////////////// 
 // and here index.php //
 ////////////////////////

 $autloader = new Classes\ClassLoader;
 spl_autoload_register(array($autloader, 'handle'));
 $user = new \framework\classes\User();
 $user->helloWorld();