PHP 5.4: Accessor with trait example

php-5.4-accessor-with-trait.php

<?php
// Example code how to eliminate getter and setter methods
// with traits introduced from PHP 5.4

trait Accessors {
  public function __get($name) {
    if ($this->r_property[$name])
      return $this->$name;
    else
      trigger_error("Access to read protected property");
  }

  public function __set($name, $value) {
    if ($this->w_property[$name])
      $this->$name = $value;
    else 
      trigger_error("Access to write protected property");
  }
}

class OrderLine {
  use Accessors;

  private $r_property = array('price'=>1, 'amount'=>1);
  private $w_property = array('price'=>0, 'amount'=>1);

  protected $price;
  private $amount;
  private $tax = 1.15; // property without getter/setter

  public function getTotal() {
    return $this->price * $this->amount * $this->tax;
  }
}

$line = new OrderLine;

$line->price = 20;
$line->amount = 3;

echo "Total cost: ".$line->getTotal();
?>

For IDE visibility we can use PhpDoc

How would you do inheritance with this (assuming you are using Accessor in both the parent and the child)? Or is it even possible?