I think there is a small issue still. The & is xml escaped twice.
The problem comes from the fact that you don’t need to xml escape your data yourself with neither htmlspecialchars nor htmlentities because the DomDocument takes care of this protection. I removed those instructions and it works.
Of course, you can’t simply display this output XML in a web page, you must do a htmlentities( $xml->saveXML() ) to see the final string.

The only thing I don’t like with the DomDocument class, is that it doesn’t xml escape the simple quote (‘) as it should (it works for & ” but not ‘ ). They consider they will never internally use a (‘) as reserved xml char (but use ” instead) so they don’t need to encode the (‘). It’s a small mistake in my humble opinion.

When converting Arrays where the index is a numeric version, eg:

[similarArtists] => Array
        (
            [0] => Array
                (
                    [name] => Freddie Mercury
                    [match] => 1
                )
 
            [1] => Array
                (
                    [name] => Brian May
                    [match] => 0.656711
                )

Converts into XML as…

<similarArtists>
<name>Freddie Mercury</name>
<match>1</match>
</similarArtists>
<similarArtists>
<name>Brian May</name>
<match>0.656711</match>
</similarArtists>

Where ‘similarArtists’ should be one container node with 0,1,2 etc sub nodes.

Any thoughts?

I just did a little tweak to your code though, in method Array2XML::createXML, I replaced this line:


$xml->appendChild(self::convert($node_name, $arr));


to this.


if (count($arr) > 1) {
$xml->appendChild(self::convert($node_name, $arr));
} else {
$root_element = array_pop(array_keys($arr));
$xml->insertBefore(self::convert($root_element, $arr[$root_element]));
}


Why? Because sometimes I want to use the first array key found to be the root element. Instead of having to specify a new root element as the container.