Add element to XML when not existing in child PHP - php

Question

<?xml version="1.0" encoding="UTF-8"?>
<products>
<product>
<a>product a</a>
<b>data</b>
<c>data</c>
</product>
<product>
<a>product b</a>
<c>data</c>
</product>
</products>
When child-element < B > is missing, i want to add it to the XML file. so the < product > ends up like this.No data has to be added, just the element.
<product>
<a>data</a>
<c>data</c>
<b></b>
</product>
can this be done with simplexml ?
<?php
$xml = simplexml_load_file("xml.xml", NULL, TRUE);
foreach ($xml->children() as $child) {}

Answer 1

This is definitely possible. Here's an example of how to do it (assuming you're not worried about the order in which the child element occurs):
$xml = new SimpleXMLElement('xml.xml', NULL, TRUE);
foreach ($xml->children() as $child) {
if (isset($child->b)) {
continue;
}
$child->b = '';
}
// output to new file
$xml->asXML('xml2.xml');
You can also find an online Demo that contains all data:
<?php
/**
* Add element to XML when not existing in child PHP
* #link http://stackoverflow.com/q/19562757/367456
*/
$xml = new SimpleXMLElement('<r><product><b>hello</b></product><product/><product/></r>');
foreach ($xml->children() as $child) {
if (isset($child->b)) {
continue;
}
$child->b = '';
}
$xml->asXML('php://output');
Program Output (beautified):
<?xml version="1.0"?>
<r>
<product>
<b>hello</b>
</product>
<product>
<b></b>
</product>
<product>
<b></b>
</product>
</r>