#28176 [Opn->Sus]: isset() returns false for properties returned from __get()

ID: 28176 Updated by: helly@php.net Reported By: benjcarson at digitaljunkies dot ca -Status: Open +Status: Suspended -Bug Type: Zend Engine 2 problem +Bug Type: Feature/Change Request -Operating System: Linux +Operating System: * -PHP Version: 5CVS-2004-04-27 (dev) +PHP Version: 5.0.* New Comment: We'd need a new handler. Say __exists($name). But not before 5.0 is out. Previous Comments: ------------------------------------------------------------------------ [2004-04-27 17:30:37] benjcarson at digitaljunkies dot ca It may come as no surprise, but I figure I should also mention it here for completeness: empty() displays the same behaviour--it does not call __get() either and returns true for variables that are set and retrieved via __get(). Obviously I agree with amt at php.net and think these are bugs. For now, I'm working around this with: !is_null($f->key); From a user's point of view, the fact that this works and isset()/empty() do not is inconsistent. Of course, knowing that isset()/empty() are language constructs and is_null() a function explains the behaviour, but I still think it is incorrect. ------------------------------------------------------------------------ [2004-04-27 08:42:15] amt@php.net Hum. I think it's a good idea to modify isset() to call __get() and __set(). Otherwise, it breaks the principle of encapsulation. As a user of the class, I'm not supposed to know/care if I'm accessing the properties directly or if the developer has overloaded the property handler. Besides, how else as a user can I check if a property is set if I can't use isset()? ------------------------------------------------------------------------ [2004-04-27 08:31:59] derick@php.net 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 This is correct behavior, isset() does not call the __get and __set handlers. ------------------------------------------------------------------------ [2004-04-27 03:57:42] benjcarson at digitaljunkies dot ca Description: ------------ isset() returns false for variables that are returned using the __get() method, even though the variables are set and their values are returned properly. Reproduce code: --------------- <?php class Foo { var $arr; function __get($var) { return $this->arr[$var]; } } class Bar { var $var; function __get($tmp) { return $this->var; } } $f = new Foo(); $f->arr["key"] = "val"; var_dump($f->key); // Value returned correctly var_dump(isset($f->key)); // isset() disagrees $b = new Bar(); $b->var = "blah"; var_dump($b->dummy); // Value returned correctly var_dump(isset($b->dummy)); // isset() returns false ?> Expected result: ---------------- string(3) "val" bool(true) string(4) "blah" bool(true) Actual result: -------------- string(3) "val" bool(false) string(4) "blah" bool(false) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=28176&edit=1