How do I change XML tag names with PHP?

Question

I have an XML file that looks something like this:

<product>
<modelNumber>Data</modelNumber>
<salePrice>Data</salePrice>
</product>
 <product>
<modelNumber>Data</modelNumber>
<salePrice>Data</salePrice>
</product>

Is there a simple way to change the tag names , to something else such as model, price.

Essentially, I have a bunch of XML files containing similar data, but in different formats, so I'm looking for a simple way to parse the XML file, change certain tag names, and write a new XML file with the changed tag names.

The files are provides by multiple sources -- the tag names are uncontrolled by me. — Ryan, Nov 17 '11 at 07:19
So errors like `Data` (different ending/closing tag) are normal? Because then you won't really be able to parse this document with an XML parser (like PHP DOM). — kapa, Nov 17 '11 at 07:20
No. That was a bug on my part when typing it. I just read it over. — Ryan, Nov 17 '11 at 07:22

score 8 · Answer 1 · answered Dec 14 '12 at 16:16

There are two issues with Kris and dfsq code:

Only first child node will be copied - solved with temporary copy of $childNodes)
Children will get xmlns tag - solved by replacing node at the beginning - so it's connected to the document

A corrected renaming function is:

function renameTag( DOMElement $oldTag, $newTagName ) {
    $document = $oldTag->ownerDocument;

    $newTag = $document->createElement($newTagName);
    $oldTag->parentNode->replaceChild($newTag, $oldTag);

    foreach ($oldTag->attributes as $attribute) {
        $newTag->setAttribute($attribute->name, $attribute->value);
    }
    foreach (iterator_to_array($oldTag->childNodes) as $child) {
        $newTag->appendChild($oldTag->removeChild($child));
    }
    return $newTag;
}

dfsq · Accepted Answer · 2011-11-18T06:31:57.257

Next function will do the trick:

/**
 * @param $xml string Your XML
 * @param $old string Name of the old tag
 * @param $new string Name of the new tag
 * @return string New XML
 */
function renameTags($xml, $old, $new)
{
    $dom = new DOMDocument();
    $dom->loadXML($xml);

    $nodes = $dom->getElementsByTagName($old);
    $toRemove = array();
    foreach ($nodes as $node)
    {
        $newNode = $dom->createElement($new);
        foreach ($node->attributes as $attribute)
        {
            $newNode->setAttribute($attribute->name, $attribute->value);
        }

        foreach ($node->childNodes as $child)
        {
            $newNode->appendChild($node->removeChild($child));
        }

        $node->parentNode->appendChild($newNode);
        $toRemove[] = $node;
    }

    foreach ($toRemove as $node)
    {
        $node->parentNode->removeChild($node);
    }

    return $dom->saveXML();
}

// Load XML from file data.xml
$xml = file_get_contents('data.xml');

$xml = renameTags($xml, 'modelNumber', 'number');
$xml = renameTags($xml, 'salePrice', 'price');

echo '<pre>'; print_r(htmlspecialchars($xml)); echo '</pre>';

Write into file (easiest way) with `file_put_contents('filename.xml', $xml);` — dfsq, Nov 18 '11 at 11:50

score 1 · Answer 3 · edited May 23 '17 at 12:33

There is some sample code that works in my question over here, but there is no direct way of changing a tag name through DOMDocument/DOMElement, you can however copy elements with a new tagname as shown.

basically you have to:

function renameTag(DOMElement $oldTag, $newTagName)
{
    $document = $oldTag->ownerDocument;

    $newTag = $document->createElement($newTagName);
    foreach($oldTag->attributes as $attribute)
    {
        $newTag->setAttribute($attribute->name, $attribute->value);
    }
    foreach($oldTag->childNodes as $child)
    {
        $newTag->appendChild($oldTag->removeChild($child));
    }
    $oldTag->parentNode->replaceChild($newTag, $oldTag);
    return $newTag;
}

How do I change XML tag names with PHP?

3 Answers3

Linked