How to ignore a PHP catchable fatal error from QueryPath?

Question

I'm scraping some data from a website using QueryPath. However, every so often I receive the error message below and the script terminates.

PHP Catchable fatal error:  Argument 1 passed to DOMXPath::__construct() must be an instance of DOMDocument, null given, called in ....inc/QueryPath/QueryPath/CSS/DOMTraverser.php on line 417 and defined in ....inc/QueryPath/QueryPath/CSS/DOMTraverser.php on line 467

The error doesn't give me any clues as to which line of my code the error is coming from, but assuming it was coming from $outHtml = htmlqp($outHtml); I tried prefixing the htmlqp command with @htmlqp.

This didn't work, so I then tried wrapping htmlqp in a catch{} statement which didn't seem to help either.

All I want to do is ignore the error and continue rather than having the script bomb out. Help!

possible duplicate http://stackoverflow.com/questions/2468487/how-can-i-catch-a-catchable-fatal-error-on-php-type-hinting — bitWorking, Jul 25 '13 at 16:37
You don't wrap `htmlqp` with the `catch`, you wrap it with the `try` and then handle it in the `catch` block. — Kevin Ji, Jul 25 '13 at 16:49

score 2 · Accepted Answer · answered Jul 25 '13 at 16:37

2

It's a catchable fatal error .. so catch it.

If you catch it you can get a full stacktrace.

Ex:

try {
   thisfunctionthrowsanexception();
} catch (Exception $e) {
    var_dump(get_class($e));
    echo $e->getTraceAsString();
}

@ hides errors. You don't ever want to have to use that.

answered Jul 25 '13 at 16:37

Halcyon

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Yes, I've already tried catching it, but I'm not 100% sure that the error is generated by the htmlqp() command as the error does not detail which line in my script caused it. If its not htmlqp() it could be any one of hundreds of commands I use to traverse the DOM tree. – James Jul 25 '13 at 16:42
Put the try catch around your entire script and you'll be able to find out. – Halcyon Jul 25 '13 at 16:46
Good idea. I'll give that a try and see what it throws up. Unfortunately its a waiting game as the script can run for minutes or days before giving the error – James Jul 25 '13 at 17:23

score 1 · Answer 2 · answered Oct 18 '16 at 00:17

I was just trying to solve the opposite problem in some production code: the type hinting is not working at all. I traced the culprit down to the following code:

set_error_handler('errorHandler');

function errorHandler($errno, $errstr, $errfile, $errline) {
    // Whole bunch of irrelevant code
    // ...

    return;
}

It handles the error... by essentially doing nothing!

How to ignore a PHP catchable fatal error from QueryPath?

2 Answers2