options-improvement-2.php

Using a static OptionSupport class that automatically writes options into properties

+ Options are set in the very beginning of the constructor
+ Concise
+ Error if option is not supported
+ Everything is a property, no special treatment of options

~ Medium performance. Reflection is slow, but some things can be cached so it is faster than addOption()

- Options need to be converted to camel case
- Problems with accessing required options before parent::__construct()

<?php

class Thing
{
    public static $options = array('required');

    public static $requiredOptions = array('required');

    protected $required = false; // default value is false

    public function __construct(array $options = array())
    {
        OptionSupport::initialize($this, $options);
    }
}

// WHAT'S REALLY UGLY: Accessing options before parent::__construct()

class OtherThing extends Thing
{
    public static $options = array('newoption');

    public static $requiredOptions = array('newoption');

    protected $newoption;

    // this could even be in the parent class so that you don't even know
    // that doSomethingBeforeParentConstruct() is called before the root constructor
    public function __construct(array $options = array())
    {
        $this->doSomethingBeforeParentConstruct();

        parent::__construct($options);
    }

    public function doSomethingBeforeParentConstruct()
    {
        // newoption is an required option, so we assume it is there
        $this->newoption->doSomething(); // BOOM! newoption is NULL
    }
}