# [PATCH] Late Static Binding

- Thread: https://externals.io/message/21991
- Original archive: https://news-web.php.net/php.internals/21991
- Started by Mike Lively on 2006-02-23T22:06:02+00:00
- Messages: 4
- Reply by email to internals@lists.php.net
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## #21991 — Mike Lively — 2006-02-23T22:06:02+00:00

URL: https://externals.io/message/21991#21991

I have finished a patch that implements a working version of late static
binding.

I used the notes from the Paris PDM as my guidelines for implementation.
(http://www.php.net/~derick/meeting-notes.html#late-static-binding-using-this-without-or-perhaps-with-a-different-name) As requested in the notes I reused 'static::'. I also wrote a few tests not only to test the new functionality but also to make sure 'static' can't be inherited or extended. 

I also added a new function get_caller_class() which returns the name of
the class that static:: would represent.

(borrowing from PDM notes)
In php5.* the following script outputs "A::static2":

<?php
        class A {
                static function staticA() {
                        self::static2();
                }

                static function static2() {
                        echo "A::static2\n";
                }
        }

        class B extends A {
                static function static2() {
                        echo "B::static2\n";
                }
        }

        B::staticA();
?>

This has somewhat recently been highlighted by different developers to
be somewhat problematic behavior in creating user friendly APIs. If you
want to see a possible use for it you need look no further than the
example ZActiveRecord API that was used in their webcast with php|arch.
(http://blog.joshuaeichorn.com/archives/2006/01/09/zactiverecord-cant-work/) Currently the code laid out there is impossible short of some ugly use of `debug_backtrace()` and file parsing :/. This patch of course would allow that kind of code too exist.

In a small example based on the one I gave earlier you could change the
code too the following and have it print "B::static2":

<?php
        class A {
                static function staticA() {
                        static::static2();
                }

                static function static2() {
                        echo "A::static2\n";
                }
        }

        class B extends A {
                static function static2() {
                        echo "B::static2\n";
                }
        }

        B::staticA();
?>

As far as current userland code impact, there is very little as far as I
can tell. No keywords have been added, just another use for an existing
one. No changes were made to self:: or parent:: so the change should be
pretty transparent. The only thing that I see remotely causing any
issues would be the new function (get_caller_class().) I added that just
to complete the set so to speak.

----------
Mike Lively (ds- on irc.efnet.org)
"Our Schwartz is bigger than yours"

---

## #21999 — Lukas Smith — 2006-02-24T14:52:02+00:00

URL: https://externals.io/message/21991#21999 · In reply to: #21991

Mike Lively wrote:

> As far as current userland code impact, there is very little as far as I
> can tell. No keywords have been added, just another use for an existing
> one. No changes were made to self:: or parent:: so the change should be
> pretty transparent. The only thing that I see remotely causing any
> issues would be the new function (get_caller_class().) I added that just
> to complete the set so to speak.

I will try to find time to test this patch. But it will be another few 
days before I have time to revive my linux vmware instance.

However I just wanted to mention that I would really love to see this 
feature in php 6 or even php 5.2.x

regards,
Lukas

---

## #22044 — Marcus Boerger — 2006-03-01T10:00:31+00:00

URL: https://externals.io/message/21991#22044 · In reply to: #21991

Hello internals,

   it looks like either nobody objects or nobody has interest. Either way
i tested the patch and worked helped it a bit and it looks good, doesn't
affect anything else and doesn't show a single problem in valgrind. So If
noone objects i will commit this next week.

regards
marcus

special mail to andi :-)


Thursday, February 23, 2006, 11:06:02 PM, you wrote:

> I have finished a patch that implements a working version of late static
> binding.

> I used the notes from the Paris PDM as my guidelines for implementation.
> (http://www.php.net/~derick/meeting-notes.html#late-static-binding-using-this-without-or-perhaps-with-a-different-name)
> As requested in the notes I reused 'static::'. I also wrote a few tests
> not only to test the new functionality but also to make sure 'static' can't be inherited or extended.

> I also added a new function get_caller_class() which returns the name of
> the class that static:: would represent.

> (borrowing from PDM notes)
> In php5.* the following script outputs "A::static2":

> <?php
>         class A {
>                 static function staticA() {
>                         self::static2();
>                 }

>                 static function static2() {
>                         echo "A::static2\n";
>                 }
>         }

>         class B extends A {
>                 static function static2() {
>                         echo "B::static2\n";
>                 }
>         }

>         B::staticA();
?>>

> This has somewhat recently been highlighted by different developers to
> be somewhat problematic behavior in creating user friendly APIs. If you
> want to see a possible use for it you need look no further than the
> example ZActiveRecord API that was used in their webcast with php|arch.
> (http://blog.joshuaeichorn.com/archives/2006/01/09/zactiverecord-cant-work/)
> Currently the code laid out there is impossible short of some ugly use of
> `debug_backtrace()` and file parsing :/. This patch of course would allow that kind of code too exist.

> In a small example based on the one I gave earlier you could change the
> code too the following and have it print "B::static2":

> <?php
>         class A {
>                 static function staticA() {
>                         static::static2();
>                 }

>                 static function static2() {
>                         echo "A::static2\n";
>                 }
>         }

>         class B extends A {
>                 static function static2() {
>                         echo "B::static2\n";
>                 }
>         }

>         B::staticA();
?>>

> As far as current userland code impact, there is very little as far as I
> can tell. No keywords have been added, just another use for an existing
> one. No changes were made to self:: or parent:: so the change should be
> pretty transparent. The only thing that I see remotely causing any
> issues would be the new function (get_caller_class().) I added that just
> to complete the set so to speak.

---

## #22069 — Jeff Moore — 2006-03-01T23:04:28+00:00

URL: https://externals.io/message/21991#22069 · In reply to: #21991

> I also added a new function get_caller_class() which returns the name 
> of
> the class that static:: would represent.

I find get_caller_class() a bit confusing because it introduces new 
terminology (caller).  May I suggest adding:

get_self_class()  // corresponds to self
get_static_class() // corresponds to static

This already exists:
 `get_parent_class()` // corresponds to parent

What should `get_class()` return inside of a static method?  I frankly 
don't care, because I would always use get_self_class() or 
get_static_class() so that the meaning was explicit.

Thanks for the patch, I'm excited about this one.  Oh, using the key 
word static doesn't bother me at all.

Best Regards,

Jeff