<?php

class Something
{
    protected $_another;

    public function __construct (array $options = null)
    {
        if (is_array($options)) {
            $this->setOptions($options);
        }
    }

    public function __set ($name, $value)
    {
        $method = 'set'.$name;
        if (!method_exists($this, $method)) {
            throw new Exception('Tried to set invalid property: '.$name);
        }
        $this->$method($value);
    }

    public function __get ($name)
    {
        $method = 'get'.$name;
        if (!method_exists($this, $method)) {
            throw new Exception('Tried to get invalid property: '.$name);
        }
        return $this->$method();
    }

    public function setOptions (array $options)
    {
        $methods = get_class_methods($this);
        foreach ($options as $key => $value) {
            $method = 'set'.ucfirst($key);
            if (in_array($method, $methods)) {
                $this->$method($value);
            }
        }
        return $this;
    }

    public function setAnother ($val)
    {
        $this->_something = $val;
        return $this;
    }

    public function getAnother ()
    {
        return $this->_another;
    }
}
?>
<?php
// test case
$something = new Something();
$something->another = 'test';
echo $something->another;
?>

#Error:
Fatal error:  Uncaught exception 'Exception' with message 'Tried to set invalid property: _something' in /home/sss/Projects/my/public/test.php:19
Stack trace:
#0 /home/sss/Projects/my/public/test.php(47): Something->__set('_something', 'test')
#1 /home/sss/Projects/my/public/test.php(21): Something->setAnother('test')
#2 /home/sss/Projects/my/public/test.php(58): Something->__set('another', 'test')
#3 {main}
  thrown in /home/sss/Projects/my/public/test.php on line 19