PHP only replace 1 node of a series - php

Question

I have an XML file that currently has 4 nodes with the same name:
The file looks like this: (data.xml)
<?xml version="1.0"?>
<products>
<product>
<ItemId>531670</ItemId>
<modelNumber>METRA ELECTRONICS/MOBILE AUDIO</modelNumber>
<name>Buy</name>
<name>Car, Marine & GPS</name>
<name>Car Installation Parts</name>
<name>Deck Installation Parts</name>
<name>Antennas & Adapters</name>
</product>
</products>
There are 4 nodes with the same name. (the name node).
I then use this PHP code to replace the node names
<?php
/**
* #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, 'name', 'newName');
echo $xml;
?>
This function replaces all of the name nodes with newName; however, I want to only replace one instance of the name tag because I want to rename each of the name tags.
If I call another
$xml = renameTags($xml, 'name', 'newName2');
It wont work, it will only use the first instance of $xml.
Any Idea how I can change my code to allow me to replace each name node individually?

Answer 1

If you simply want to rename the first node you encounter, add a break; statement at the end of your first foreach loop like this first example. However, this is horribly inefficient and a better way to do it is demonstrated in the second (CORRECT) example at the bottom.
THE WRONG WAY
Everytime you replace XML like this an angel sheds a tear ...
$src = "
<products>
<product>
<ItemId>531670</ItemId>
<modelNumber>METRA ELECTRONICS/MOBILE AUDIO</modelNumber>
<name>Buy</name>
<name>Car, Marine & GPS</name>
<name>Car Installation Parts</name>
<name>Deck Installation Parts</name>
<name>Antennas & Adapters</name>
</product>
</products>
";
function renameTags($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[] = $node;
break;
}
foreach ($toRemove as $node)
{
$node->parentNode->removeChild($node);
}
$dom->formatOutput = TRUE;
return $dom->saveXML();
}
$xml = renameTags($src, 'name', 'newName');
echo $xml;
THE CORRECT WAY
function renameTags($xml, $old, $new)
{
$dom = new DOMDocument();
$dom->loadXML($xml);
// find the first node with the specified tag name
$oldNode = $dom->getElementsByTagName($old)->item(0);
// clone the node (deep copy)
$doppelganger = $oldNode->cloneNode(TRUE);
// import our cloned node to this dom document
$doppelganger = $dom->importNode($doppelganger, true);
// Create new node with the value from the copied node
$newNode = $dom->createElement($new, $doppelganger->nodeValue);
// update all the attributes of the new node with those from the copy
foreach ($doppelganger->attributes as $attrName => $attrNode) {
$newNode->setAttribute($attrName, $attrNode);
}
// append the newNode copy to the dom
$oldNode->parentNode->appendChild($newNode);
// remove the old node
$oldNode->parentNode->removeChild($oldNode);
$dom->formatOutput = TRUE;
return $dom->saveXML();
}