Question

I am using XPath to query an xml document and then copy found nodes to a separate results xml file, however the problem I am having is that the XML declaration at the top gets added each time a new node is added to the results file.

Here is my php code:

$allEventsForVenue = $xPath->query(
            "/Ticket/EventsPoints/Event[contains(PerformanceName,'$searchParam')]"
    );

    foreach ($allEventsForVenue as $event) {

         $dstDom = new DOMDocument('1.0', 'utf-8');
         $dstDom->appendChild($dstDom->createElement('EventsPoints'));
         $dstDom->documentElement->appendChild($dstDom->importNode($event, true));
         //echo $dstDom->saveXml();
         $dstDom->formatOutput = true;
         $strxml .= $dstDom->saveXML();
         $handle = fopen("/var/www/html/xml/searchresults$searchID.xml", "w");
         fwrite($handle, $strxml);
         fclose($handle); 
    } 

Invalid XML File (two xml declarations in the one file):

->>         <?xml version="1.0" encoding="utf-8"?>
            <EventsPoints>
              <Event ID="17">
                    <PerformanceName>Bressie</PerformanceName>
                    <PresaleTime/>
                    <PriceRange>17 - 17</PriceRange>
                    <VenueID ID="19"/>
                </Event>
            </EventsPoints>
->>         <?xml version="1.0" encoding="utf-8"?>
            <EventsPoints>
              <Event ID="180">
                    <PerformanceName>U2</PerformanceName>
                    <PriceRange>20 - 20</PriceRange>
                    <VenueID ID="198"/>
                </Event>
            </EventsPoints>

Answer 1

You are creating new DOMDocument instance in loop. Also you are writing in each iteration. This is making new XML document on each iteration and its get appended in your xml file. What you need to do is, loop the XML generation part. Not the whole thing.

If you loop only the appendChild parts, your problem will be solved.

$dstDom = new DOMDocument('1.0', 'utf-8');
$dstDom->formatOutput = true;    

foreach ($allEventsForVenue as $event) {
     $dstDom->appendChild($dstDom->createElement('EventsPoints'));
     $dstDom->documentElement->appendChild($dstDom->importNode($event, true));
}

file_put_contents("/var/www/html/xml/searchresults$searchID.xml", $dstDom->saveXML());