Decorate Anything

• Synopsis
• Installation
• Requirements
• Usage

Synopsis

This package is a simplified implementation of the Decorator Design Pattern. Sub classes of the provided Decorator class may be used to decorate any objects without the need for abstract components and abstract decorators for each of them thanks to PHP's magic methods and loose typification.

Installation

You can just download Decorator.php and include it anywhere, but I recommend using composer:

require: {
    "sgh/decorate-anything": "~2.0"
}

Requirements

The package requires PHP 5.3 or later.

Usage

To create a decorator for a component, say ConcreteComponent, just extend the Decorator like this:

class ConcreteDecorator extends \SGH\DecorateAnything\Decorator
{
    const COMPONENT_CLASS = 'ConcreteComponent';
}

To extend functionality of a component method in the decorator, use the parent keyword like you would do in the original decorator pattern:

public function foo()
{
    parent::foo();
    some_special_functionality();
}

Now you can decorate your component like this:

$component = new ConcreteDecorator(new ConcreteComponent());

$component will have the same interface as ConcreteComponent, you also can access the public properties of the decorated component.

$component->foo();
$component->bar(1,2); // assuming a method ConcreteComponent::bar($x,$y)
var_dump($component->baz); // assuming a property ConcreteComponent::$baz
var_dump(isset($component->baz));
$component->baz = 1;
unset($component->baz);

If you really have to name the common interface of decorator and compontent explicitly do it this way:

interface IConcreteComponent
{
    public function foo();
    public function bar($x,$y);
}
class ConcreteComponent implements IConcreteComponent
{
    public $baz = 'baz';
    public function foo()
    {
        // implementation
    }
    public function bar($x,$y)
    {
        // implementation
    }
}
class ConcreteDecorator extends \SGH\DecorateAnything\Decorator implements IConcreteComponent
{
    const COMPONENT_CLASS = 'ConcreteComponent';
    public function foo()
    {
        parent::foo();
        // additional implementation
    }
    public function bar($x,$y)
    {
        return parent::bar($x,$y);
    }
}