Decorator Implementation

decorator.php

<?php

class Ruler {
    // Returns in meters
    public function measure(Point $a, Point $b) {
    }
}

class SAEDecorator {
    protected $ruler;
    public function __construct(Ruler $ruler) {
        $this->ruler = $ruler;
    }
    // Returns in feet
    public function measure(Point $a, Point $b) {
        return 3.2808399 * $this->ruler->measure($a, $b);
    }
}