Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:97480
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain rochette.cc designates 62.210.206.189 as permitted sender)
To: PHP internals <internals@lists.php.net>
Message-ID: <2aecc3f2-5e9d-907f-029b-5c60eb134b33@rochette.cc>
Date: Thu, 29 Dec 2016 14:12:33 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:51.0) Gecko/20100101
 Thunderbird/51.0a2
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Subject: Decorator classes
From: mathieu@rochette.cc (Mathieu Rochette)

Hello internals,

I find that using the decorator pattern is very verbose and maybe 
something could be done about that,
an article[1] I saw proposed a "decorates" keyword to solves this, here 
is how it might look like in PHP:

interface Foo {
   public bar();
   public taz();
}

class EchoFooBar decorates Foo {
   public function bar() {
     $this->logger->debug("foo bar");
     return $this->decorated->bar();
   }
}

class LoggedFooTaz decorates Foo {
   private $logger;

   public function __construct(Foo $decorated, Logger $logger) {
     $this->logger = $logger;
     $this->decorated = $decorated;
   }

   public function taz() {
     $this->logger->debug("foo taz");
     return $this->decorated->taz();
   }
}

* the constructor is optional and default to take the first argument and 
put it in $decorated
* if the constructor is provided PHP check that $decorated is set and 
implements the decorated interface or class
* all public methods not overridden are automatically proxied to the 
decorated object

There is at least a few different ways to go about this, the previous 
example was just to give you a preview of what it could be. If there is 
interest I'd like to write an RFC for this :)

What do you think about this ?


thank you


[1] https://dzone.com/articles/is-inheritance-dead