ID: 44411 Comment by: hubert dot roksor at gmail dot com Reported By: phpbugs at steve dot ipapp dot com Status: Open Bug Type: SimpleXML related Operating System: ANY PHP Version: 5.2.5 New Comment:
As per the manual chapter you quoted, the comparison operator compares _objects_, and that's the key word here. You expect two equal XML trees to be represented by two equal objects, and even though this expectation is understandable, it is simply not the case. Those objects are different. In fact, even if $sax1->value is equal to $sax1->value and they come from the same tree, they are not identical. ($sax1->value !== $sax1->value) The bottom line is the comparison operator compares objects. If you need an operator that understands the underlying data you will have to use another mean. The solution proposed in the other bug report (compare them as XML strings) sounds reasonable. It would be nice to mention this quirk in the manual though, perhaps as a new example? "Comparing Elements and Elements" Previous Comments: ------------------------------------------------------------------------ [2008-03-12 01:35:37] phpbugs at steve dot ipapp dot com Description: ------------ In PHP 5.0.x and 5.1.x two SimpleXMLElement objects were considered equal if they represented the same data. In PHP 5.2.x this does not seem to be the case anymore. This was previously listed as bug 39866 [http://bugs.php.net/bug.php?id=39866], but for some reason this was listed as bogus. In that bug it was noted that we should look at Example 5 at http://php.net/simplexml. I'm assuming this is Example 6 now [Comparing Elements and Attributes with Text] , but this is incorrect as comparision will implicity cast it to string anyway. According to http://www.php.net/manual/en/language.oop5.object-comparison.php: "When using the comparison operator (==), object variables are compared in a simple manner, namely: Two object instances are equal if they have the same attributes and values, and are instances of the same class... On the other hand, when using the identity operator (===), object variables are identical if and only if they refer to the same instance of the same class." Furthermore this backwards incompatible change is not listed in : http://us.php.net/manual/en/migration52.incompatible.php. Currently there is no equals method that we can call to get the previous functionality back, and at the present moment this makes == no longer transitive as especially since this makes == no longer transitive as 'doc' == x1, 'doc' == x2, but x1 != x2. I do not understand why ==, nor do I see value in, doing a strict comparison for SimpleXMLObjects as ==, when according to the PHP Object Comparison manual this should be ===. Therefore I believe this is a bug. Reproduce code: --------------- $xmldoc = "<xml><value>foo</value></xml>"; $sax1 = new SimpleXMLElement("$xmldoc"); $sax2 = new SimpleXMLElement("$xmldoc"); if($sax1 == $sax2) { echo "TRUE"; } else { echo "FALSE"; } echo "\n\n\n"; Expected result: ---------------- TRUE Actual result: -------------- FALSE ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=44411&edit=1
