ID: 41461 User updated by: ralph at smashlabs dot com Reported By: ralph at smashlabs dot com Status: Bogus Bug Type: Class/Object related Operating System: * PHP Version: * New Comment:
PS. I did check this with the internals list before I posted.. And I think you actually confirmed it for me on the list http://news.php.net/php.internals/29646 Thank you for your time, -ralph Previous Comments: ------------------------------------------------------------------------ [2007-05-28 17:42:50] ralph at smashlabs dot com I am sorry, perhaps I should rephrase (I was rushed when I wrote the original bug report) and I don't think I was especially clear. In general, we are speaking strictly of Method Overriding. PHP currently allows concrete classes to override methods in abstract classes as demonstrated by this code: [EMAIL PROTECTED] ~/tmp $ cat test_method_override.php <?php error_reporting(E_ALL | E_STRICT); class Z_Abstract { public function someFunc($one, $two) { } } class Z_Concrete extends Z_Abstract { public function & someFunc($uno, $dos, $tres) { } } $o = new Z_Concrete(); [EMAIL PROTECTED] ~/tmp $ php test_method_override.php [EMAIL PROTECTED] ~/tmp $ As you can see, no E_STRICT was triggered, thus allowing the concrete class to override the method from the abstract class. On the other hand, when adding an _empty_ interface to the superclass hierarchy, the behavior changes. The simple inclusion of an interface now (albeit empty) seemingly shouldn't add any complexities to method overriding for methods outside the scope of the interface itself. I have done a bit more homework, and it seems like not alot of IS_A inheritance literature exists to describe this problem, let alone justify the behavior we are seeing in practice.. See code: [EMAIL PROTECTED] ~/tmp $ cat test_method_override2.php <?php error_reporting(E_ALL | E_STRICT); interface Z_Interface { } class Z_Abstract implements Z_Interface { public function someFunc($one, $two) { } } class Z_Concrete extends Z_Abstract { public function & someFunc($uno, $dos, $tres) { } } $o = new Z_Concrete(); [EMAIL PROTECTED] ~/tmp $ php test_method_override2.php Strict standards: Declaration of Z_Concrete::someFunc() should be compatible with that of Z_Abstract::someFunc() in /home/webdeveloper/tmp/test_method_override2.php on line 14 At the very least, I looks like one of the two is broken (At least in the spirit of OOP as it relates to polymorphism and overriding methods.) ------------------------------------------------------------------------ [2007-05-28 15:08:50] [EMAIL PROTECTED] Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php PHP follows strict is_a inheritance. By the way, it is called signature and even if you could change it it would not solve the problem. And anyway it would break inheritance rules. ------------------------------------------------------------------------ [2007-05-21 23:06:13] ralph at smashlabs dot com Description: ------------ When an interface is a parent of a class, the interface is implying a specific profile for a given function (here its __get) even though it is not defined in the interface itself. This is making it impossible to overload and/or change the profile of the function in a descendant class. Reproduce code: --------------- The following will produce this notice: Strict Standards: Declaration of Z_Concrete::__get() should be compatible with that of Z_Abstract::__get() in xxx on line 16 <?php error_reporting(E_ALL | E_STRICT); interface Z_Interface { } abstract class Z_Abstract implements Z_Interface { public function __get($name) { return; } } class Z_Concrete extends Z_Abstract { public function & __get($name) { return null; } } $t = new Z_Concrete(); This code will not produce a notice: <?php error_reporting(E_ALL | E_STRICT); abstract class Z_Abstract { public function __get($name) { return; } } class Z_Concrete extends Z_Abstract { public function & __get($name) { return null; } } $t = new Z_Concrete(); The only difference is that the former has an interface as a parent, the latter does not. Expected result: ---------------- No E_STRICT notice raised Actual result: -------------- E_STRICT notice raised. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=41461&edit=1
