From: Operating system: PHP version: 5.3.4 Package: Class/Object related Bug Type: Feature/Change Request Bug description:Allow __toString() to throw exceptions
Description: ------------ Currently, when casting an object with __toString() to a string, __toString() is not allowed to throw an exception. Trying to do so triggers an E_ERROR "Method %s::__toString() must not throw an exception". IMHO, this is counter-intuitive, especially since calling that object's __toString() method directly would correctly throw the exception. I propose to allow __toString() to throw exceptions. Note: this was already reported in http://bugs.php.net/bug.php?id=50699 but marked as bogus with the only explanation being "__toString must not throw". So, I'm marking this as a feature request rather than a bug, since the current behaviour seems to be expected (though it is not documented in http://php.net/manual/en/language.oop5.magic.php#language.oop5.magic.tostring). I also found this entry http://stackoverflow.com/questions/2429642/why-its-impossible-to-throw-exception-from-tostring which cites Johannes saying this requires major changes in the code. However, the article mentioned is from 2007 and I think the limitations in ZE that prevented this to be implemented were lifted since then. I'm not very versed in PHP's inner workings, but attached is a tentative patch which seems to fix this issue. Test script: --------------- <?php class CustomException extends Exception { } class Foo { public function __toString() { throw new CustomException('oops!'); } } $foo = new Foo(); try { var_dump((string) $foo); } catch (CustomException $e) { var_dump($e); } ?> Expected result: ---------------- object(CustomException)#2 (7) { ["message":protected]=> string(5) "oops!" ["string":"Exception":private]=> string(0) "" ["code":protected]=> int(0) ["file":protected]=> string(17) "/tmp/toString.php" ["line":protected]=> int(65) ["trace":"Exception":private]=> array(1) { [0]=> array(6) { ["file"]=> string(17) "/tmp/toString.php" ["line"]=> int(71) ["function"]=> string(10) "__toString" ["class"]=> string(3) "Foo" ["type"]=> string(2) "->" ["args"]=> array(0) { } } } ["previous":"Exception":private]=> NULL } Actual result: -------------- PHP Fatal error: Method Foo::__toString() must not throw an exception in /tmp/toString.php on line 0 PHP Stack trace: PHP 1. {main}() /tmp/toString.php:0 -- Edit bug report at http://bugs.php.net/bug.php?id=53648&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=53648&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=53648&r=trysnapshot53 Try a snapshot (trunk): http://bugs.php.net/fix.php?id=53648&r=trysnapshottrunk Fixed in SVN: http://bugs.php.net/fix.php?id=53648&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=53648&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=53648&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=53648&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=53648&r=needscript Try newer version: http://bugs.php.net/fix.php?id=53648&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=53648&r=support Expected behavior: http://bugs.php.net/fix.php?id=53648&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=53648&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=53648&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=53648&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=53648&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=53648&r=dst IIS Stability: http://bugs.php.net/fix.php?id=53648&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=53648&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=53648&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=53648&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=53648&r=mysqlcfg
