options-current.php

The current way, using addOption(), addRequiredOption() and getOption()

+ Concise
+ Error if option is not supported

- Slow, because the addOption() calls are executed for every new instance
- Base class Configurable needed
- Overriding options in parent fields very intransparent
- Options need special treatment ($this->required vs. $this->getOption('required'))
- Problems with accessing required options before parent::__construct()

<?php

class Thing extends Configurable
{
    public function configure()
    {
        $this->addOption('something');

        // now we can do $this->getOption('something')
    }
}

// WHAT'S REALLY UGLY #1: Overriding parent options

class SubThing extends Thing
{
    protected function configure()
    {
        // overrides parent value because called before parent::configure()
        $this->addOption('something', 'default');

        parent::configure();

        // does not override parent value because already added
        $this->addOption('something', 'default');
    }
}

// WHAT'S REALLY UGLY #2: Accessing options before parent::__construct()

class OtherThing extends Thing
{
    // 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);
    }

    protected function configure()
    {
        $this->addRequiredOption('newoption');
    }

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