Req #67310 [Asn->Opn]: Allow abstract private functions in traits
Edit report at https://bugs.php.net/bug.php?id=67310&edit=1
ID: 67310
Updated by: kalle@php.net
Reported by: chrisb at zedcore dot com
Summary: Allow abstract private functions in traits
-Status: Assigned
+Status: Open
Type: Feature/Change Request
Package: Scripting Engine problem
Operating System: Debian GNU/Linux "wheezy"
PHP Version: 5.4.28
-Assigned To: aharvey
+Assigned To:
Block user comment: N
Private report: N
Previous Comments:
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[2014-06-12 14:33:44] chrisb at zedcore dot com
Abstract methods in traits are useful in the case where you have generic functionality which needs a
certain amount of information from the class it is being used by. Being able to add abstract methods
to traits means you can define accessor methods to get that data. The "abstract trait
members" example *in the PHP manual* is a perfect example of this.
It's not currently possible for a trait to enforce that the using class implements a particular
interface, so I don't see how that's relevant.
------------------------------------------------------------------------
[2014-06-09 16:31:31] aharvey@php.net
I'm going to RFC this post-5.6.0.
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[2014-06-06 12:53:37] kjarli at gmail dot com
I could be wrong.. But why would a trait have to tell a class what to implement? That's the job
of interfaces. Traits are just to add generic functionality to support "multiple
inheritance". Therefore I highly disagree with traits being able to mark _anything_ as abstract
and should abstract traits not be possible in my opinion.
------------------------------------------------------------------------
[2014-05-22 22:42:37] aharvey@php.net
Implemented as https://github.com/php/php-src/pull/682, but
we'll need someone with Zend karma to merge it.
------------------------------------------------------------------------
[2014-05-20 11:41:04] chrisb at zedcore dot com
Description:
------------
When using traits, the trait and the class using the trait can both access private members of the
class. The trait can also define abstract methods to enforce that the class using the trait
implements them.
However, it's not (currently) possible to define an abstract private method; it throws a fatal
error. I assume this check was add pre-traits, where it obviously didn't make sense to have
abstract private methods since they could never be overridden, but traits change this â an
abstract private method in a trait *can* be overridden by the class using the trait. Therefore I
think that it would make sense for the this check to be changed so that traits can define methods as
"abstract private".
The test script attached causes a fatal error. Replacing the trait's
"MyPrivateMethod" with an empty non-abstract function makes it print out "Hello
World" as expected.
Test script:
---------------
trait MyTrait
{
abstract private function MyPrivateMethod();
public function MyPublicMethod() {
$this->MyMethod();
}
}
class MyClass {
use MyTrait;
private function MyPrivateMethod() {
echo "Hello World";
}
}
$o = new MyClass();
$o->MyPublicMethod();
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=67310&edit=1
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