I hope I won't bother you with obvious things, but I think Stefan has
pointed out something important about LSB: the importance of the relative
access (like parent::), and the ambiguity of the context. It's not a problem
of static data.
Let me give an example, from my present real-life.
I am writing an ORM in PHP, and I really need LSB.
The principle is simple: to each table of the DB corresponds a class (a PHP
class). One table = one class. One column = one attribute.
All my PHP classes inherit from an abstract "base" class, who owns the main
abstract methods (of access to the DB, like selects, inserts, etc). The
structure of a table (which datatypes, keys, etc.) is represented through an
XML string, in a static variable, in the corresponding PHP class.
It is static because all the instances of a same class (= of a same table)
share the same structure of course; but it could be defined as not static as
well.
Now, let's say the "base" class is called "Entity".
And let's say I have an inherited class called "Client":
Abstract Class Entity {
function read()
{}
function delete()
{}
...
}
Class Client extends Entity
{
public $id;
public $first_name;
public $last_name;
static public $structure = "<? structure of Client ?>";
}
Now, imagine you are programming the "delete" function in class Entity.
And you have to use the $structure variable.
Since all the objects you are manipulating are "Client" objects (or other
inherited "table objects"), it would be logical to write:
parent::$structure
and not:
self::$structure, because Entity has no $structure variable.
The structures belong to the "table classes", not to Entity.
But "parent::$structure" has no meaning at compilation time in Entity.
There is no way for PHP to guess what you want to do: do you mean "now", or
do you mean "at run time"?
Personally, I think one should give the programmer the choice, exactly like
the programmer is given the choice between __CLASS__ (now, like it is
written steadily in the code) and get_parent_class() (at run time, like
objects are really instantiated).
I may be wrong, but I think LSB occurs every time you need to do something
in a RELATIVE way (get_parent_class(), parent::), because there is an
ambiguity upon what you consider as your reference, when you write something
like parent::$structure.
There relies the problem; it's not a question of static or not static. The
problem just frequently occurs with static variables.
Anyway, I do agree with Stanislav when he writes "I think we better spend
time on figuring out the concept".
And sorry for my commonplace prose. :)
Baptiste Autin
http://www.baptisteautin.com/
-----Original Message-----
From: Stanislav Malyshev [mailto:[EMAIL PROTECTED]
Sent: jeudi 20 septembre 2007 20:58
To: Zoe Slattery
Cc: Dmitry Stogov; 'Marcus Boerger'; 'Lukas Kahwe Smith'; 'Michael Lively';
'Etienne Kneuss'; [email protected]; 'Andi Gutmans'
Subject: Re: [PHP-DEV] [patch] Late static bindings (LSB)
> How about writing the test cases first - and then the patch?
I'm fine with that - that's why I asking people for examples of what
they want to do with it.
--
Stanislav Malyshev, Zend Software Architect
[EMAIL PROTECTED] http://www.zend.com/
(408)253-8829 MSN: [EMAIL PROTECTED]
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PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php
-----Original Message-----
From: Stanislav Malyshev [mailto:[EMAIL PROTECTED]
Sent: jeudi 20 septembre 2007 20:58
To: Zoe Slattery
Cc: Dmitry Stogov; 'Marcus Boerger'; 'Lukas Kahwe Smith'; 'Michael Lively';
'Etienne Kneuss'; [email protected]; 'Andi Gutmans'
Subject: Re: [PHP-DEV] [patch] Late static bindings (LSB)
> How about writing the test cases first - and then the patch?
I'm fine with that - that's why I asking people for examples of what
they want to do with it.
--
Stanislav Malyshev, Zend Software Architect
[EMAIL PROTECTED] http://www.zend.com/
(408)253-8829 MSN: [EMAIL PROTECTED]
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