On 29/12/2016 14:44, Alexander Lisachenko wrote:
2016-12-29 16:12 GMT+03:00 Mathieu Rochette <math...@rochette.cc
<mailto:math...@rochette.cc>>:
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:
* 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 ?
Hi! I think that language doesn't need any additional keywords for
that. What you describe is pure class inheritance and it's already
available in the language.
It is not class inheritance, as you can see in my example, the decorator
is on an interface. one point of the decorator pattern is that you don't
need to know
which class (or subclass) you are decorating. any object implementing
the interface (or extending the class if it's a class you are
decorating) can be decorated.
To be honest I use class inheritance in Go! AOP to define decorators
because of some nice features:
1. No overhead for calling non-decorated method (we can wrap only
required methods)
I think PHP could be smart enough to do that too for non-decorated
methods with the decorates keyword
1. Only one single instance of class, whereas traditional proxy and
decorator pattern will use two instances (one for the original
instance itself and one more instance for proxy/decorator)
I'm not sure decorator is appropriate here, in the article you are not
decorating[1] your class; you are outsourcing the behavior but it's not
the same
What your want can be implemented with the help of one single aspect,
applied to your codebase. Then framework will automatically create
decorators for every required class in your system. For logging
decorator example see my blogpost here:
http://go.aopphp.com/blog/2013/07/21/implementing-logging-aspect-with-doctrine-annotations/
[1] https://en.wikipedia.org/wiki/Decorator_pattern
