PHP Warning : session_start() [function.session-start]: Node no longer exists
This error is really annoying and can be hard to solve, it appears in two forms and only after a session has already been set.
This error will output two different messages :
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PHP Warning: Unknown: Node no longer exists in Unknown on line 0 PHP Warning : session_start() [function.session-start]: Node no longer exists in {session_start() file} on line 32 |
Solution is really simple, you have a SimpleXMLElement in your $_SESSION that does not deserialize properly.
Finding what variable trigger the error
PHP only tells you where the error kicks in (the session_start()), not where it really happened. To verify the diagnostic, first find your session.save_path
In PHP
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[PHP]echo ini_get('session.save_path') |
or simply
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print_r($_SESSION) |
On your server
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php -i | grep session.save_path |
Then go to this directory and open a sess_XXX file, then find a string looking like
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myVariable|O:16:"SimpleXMLElement":0:{} |
In serialized code, it means your variable myVariable is an Object, whose class name is 16 characters long and is SimpleXMLElement, 0:{} means it’s empty.
Fixing the error
You need then to add a string cast in your PHP script for this variable when you assign it to the $_SESSION
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# Invalid code $_SESSION[myVariable] = $simpleXML->node->anotherNode->variable |
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# Correct code $_SESSION[myVariable] = (string)$simpleXML->node->anotherNode->variable |
If you have a more complex SimpleXMLElement (eg : a XML node, not just a string), then use the asXML() method
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# Invalid Code $_SESSION['myVariable'] = $simpleXML->node # Accessing the variable $myVariable = $_SESSION['myVariable']; |
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# Correct Code $_SESSION[myVariable] = $simpleXML->node->asXML() # Accessing the variable $myVariable = new SimpleXMLElement($_SESSION['myVariable']); |
Don’t forget to change your access to this session variable as it will not be a SimpleXMLElement but rather a string containing XML.