How would I check if an XML element exists?

[lefteh]

My script:

 

$feed = "http://www.mysite.com/feed.xml";

$doc = new DOMDocument();
$doc->load($feed);

$entries = $doc->getElementsByTagName("entry");

$datesUsed = array();

foreach ($entries as $entry) {
        $status = $entry->getElementsByTagName("eventStatus");
        $eventStatus = $status->item(0)->getAttributeNode("value")->value;

        if ($eventStatus == $confirmed) {
                $titles = $entry->getElementsByTagName("title");
                $title = $titles->item(0)->nodeValue;

                $times = $entry->getElementsByTagName("when");

                $startTime = $times->item(0)->getAttributeNode("startTime")->value;
                $date = date(" F j, Y", strtotime($startTime));
                $time = date("g:i A", strtotime($startTime));

                if (!in_array($date, $datesUsed)) {
                        $currentnum = count($datesUsed);
                        if ($currentnum > 0) echo "<br />";
                        echo "<strong>$date</strong><br />";
                        $datesUsed[$currentnum+1] = $date;
                        $arrayyes = 1;
                }

                echo $title . " - $time<br />";
        }
}

 

The script pulls out the “when” element and its attributes. The problem is that not every entry has a when element. How can I skip these records? I am aware of a hasAttribute function, but I can’t seem to find any equivalent for elements. I’ve played around with several techniques, and nothing has worked.

 

If these entries are not skipped, the following error occurs:

Fatal error: Call to a member function getAttributeNode() on a non-object

 

Thanks in advance.

[premiso]

<?php
$feed = "http://www.mysite.com/feed.xml";

$doc = new DOMDocument();
$doc->load($feed);

$entries = $doc->getElementsByTagName("entry");

$datesUsed = array();

foreach ($entries as $entry) {
        $status = $entry->getElementsByTagName("eventStatus");
        $eventStatus = $status->item(0)->getAttributeNode("value")->value;

        if ($eventStatus == $confirmed) {
                $titles = $entry->getElementsByTagName("title");
                $title = $titles->item(0)->nodeValue;

                $times = $entry->getElementsByTagName("when");

                if (!is_object($times))
                      continue; // skip the rest of the loop if times is not an object

                $startTime = $times->item(0)->getAttributeNode("startTime")->value;
                $date = date(" F j, Y", strtotime($startTime));
                $time = date("g:i A", strtotime($startTime));

                if (!in_array($date, $datesUsed)) {
                        $currentnum = count($datesUsed);
                        if ($currentnum > 0) echo "<br />";
                        echo "<strong>$date</strong><br />";
                        $datesUsed[$currentnum+1] = $date;
                        $arrayyes = 1;
                }

                echo $title . " - $time<br />";
        }
}
?>

 

is_object test if $times is an object, if it is not skip the rest and continue the loop.