[development] nodify.module idea: 'everything is a node'
victorkane at gmail.com
Mon Jan 22 21:21:31 UTC 2007
As someone from the world of java and c++, I am fascinated in a very
non-sectarian way how the hook mechanism in general manages to allow
modules to "override" behavior proper to the core. Dries has mentioned
this in several presentations, and there is the article on OOP and
Drupal in the API docs.
In no way is this the place for disputing programming paradigms and
their relative merits.
But since someone asks for an opinion, I would like to point out that
polymorphism is not simply overriding a function by the same name, it
assumes that a virtual machine traverses a set of inherited objects
and automatically picks out the right type, and invokes its
implementation. So there wouldn't be any redundant code anywhere, and
I could write code (this is the important thing) for "nodes" that
would work for an "image" type inherited from node without changing
I am already fantasizing (and have been for some time) on what an
object oriented reverse engineering of Drupal might look like, and one
day it will have to be done.
Right now, however, when we want to override theme behavior for a
given node, we have to copy node.tpl.php to node-modulename.tpl.php
and change the default behavior; and the theme function acts like a
virtual machine and chooses the function corresponding to the "object"
by the file name.
So the theme function is actually implementing behavior proper to a
virtual machine. It may be efficient in execution, but in Drupal this
has to be done again and again.
So it is not polymorphism, in the strict sense. I have been following
much of these discussions, thinking to myself that the essence of the
problem is "what is the most efficient way to make procedural
event-driven (callback hook) code act like an OOP virtual machine."
At some point, the only way to solve things completely will be to move
to PHP5 classes or to Ruby... although in a year or so, these
languages may very well converge into a single VM... But the object
oriented paradigm is mandatory at some point. God knows when, things
are working out pretty well without it :)
On 1/22/07, Chris Johnson <cxjohnson at gmail.com> wrote:
> Aren't we really talking polymorphism here when we say we want to use
> the something like the node API "toolkit" on other objects?
> If I read and understand correctly, there are 2 major suggestions.
> One group wants to make more objects be nodes, so that this benefit is
> gained. Others don't want some other object types to be nodes and
> have suggested generalizing the node API to obtain the benefits.
> Using node-like API functions on other objects sounds like
> polymorphism to me, which is a "solved problem" so to speak. Any Java
> or C++ programmers out there who might comment on this? (I only know
> enough Java and C++ to be dangerous. :-)
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