How to generate namespace prefixed xml elements using SimpleXMLElement in PHP - php

Question

I'm trying to generate a RSS feed using PHP SimpleXMLElement, the problem is that i need to prefix elements and can't find a way to do this using the SimpleXMLElement class.
I've tried using $item->addChild('prefix:element', 'value') but in the result xml it strips the prefix, any idea why this happens ?.
I wonder if there is a way to solve this using the SimpleXMLElement or any other cleaner way than just echoing the XML.
For clarification, this is my PHP code:
$xml = new SimpleXMLElement('<rss version="2.0" xmlns:g="http://base.google.com/ns/1.0"/>');
$channel = $xml->addChild('channel');
$channel->addChild('title', 'Text');
$channel->addChild('link', 'http://example.com');
$channel->addChild('description', 'An example item from the feed.');
foreach($this->products as $product) {
$item = $channel->addChild('item');
foreach($product as $key => $value)
$item->addChild($key, $value);
}
return $xml->asXML();
And this is the example XML i'm trying to generate:
<?xml version="1.0"?>
<rss xmlns:g="http://base.google.com/ns/1.0" version="2.0">
<channel>
<title>Test Store</title>
<link>http://www.example.com</link>
<description>An example item from the feed</description>
<item>
<g:id>DB_1</g:id>
<g:title>Dog Bowl In Blue</g:title>
<g:description>Solid plastic Dog Bowl in marine blue color</g:description>
...
</item>
...
Thanks in advance

Answer 1

You need to pass the namespace uri of the prefix to add child element with prefix :
$item->addChild($key, $value, 'http://base.google.com/ns/1.0');
eval.in demo :
$xml = new SimpleXMLElement('<rss version="2.0" xmlns:g="http://base.google.com/ns/1.0"/>');
$channel = $xml->addChild('channel');
$channel->addChild('title', 'Text');
$channel->addChild('link', 'http://example.com');
$channel->addChild('description', 'An example item from the feed.');
$item = $channel->addChild('item');
$item->addChild('g:foo', 'bar', 'http://base.google.com/ns/1.0');
print $xml->asXML();