Generic Decorator in PHP

_example.php

<?php

require_once 'bar.php';
require_once 'foo.php';

$foo = new Foo;
$bar = new Bar( $foo );

$foo->set_foo( 123.4 );
$foo->set_bar( 123.4 );

// 123
echo $foo->get_foo() . "\n";
// 123.4
echo $foo->get_bar() . "\n";

// 123
echo $bar->get_foo() . "\n";
// 123,40
echo $bar->get_bar() . "\n";

$foo->set_bar( 123.6 );

// 123,60
echo $bar->get_bar() . "\n";

$bar->set_bar( 123.8 );

// 123,80
echo $bar->get_bar() . "\n";

bar.php

<?php

require_once 'generic-decorator.php';

class Bar extends GenericDecorator {

    public function get_bar() {
        return number_format( $this->obj->get_bar(), 2, ',', '' );
    }

}

foo.php

<?php

class Foo {
  
    private $_foo, $_bar;
  
    public function set_foo( $value ) {
        $this->_foo = (int) $value;
    }

    public function set_bar( $value ) {
        $this->_bar = (float) $value;
    }
    
    public function get_foo() {
        return $this->_foo;
    }
    
    public function get_bar() {
        return $this->_bar;
    }

}

generic-decorator.php

<?php

class GenericDecorator {

    protected $obj;

    public function __construct( $obj ) {
        $this->obj = $obj;
    }

    final public function __call( $method, $args ) {
        return call_user_func_array( array( $this->obj, $method ), $args );
    }

}