To circumvent this problem, you might add the 'mode' => 'simplexml' option to the serializer object. This way, you can use structures like:

'test' => array
(
[0] => array
(
'title' => 'Item 1',
),
[1] => array
(
'title' => 'Item 2',
)
)

This will result in something like

<item>
<title>Item 1</title>
</item>
<item>
<title>Item 2</title>
</item>

I spent a lot of time using this package, but it seems that in the end, it inherits limits imposed by arrays. Specifically, I couldn't figure out how to arrange for nested arrays.

For example. I'd like to create the following XML...

<root>
<contact>
<name>Mark</name>
<phoneNumbers>
<dial>5037771001</dial>
<dial>2129711001</dial>
<dial>4455543334</dial>
</phoneNumbers>
</contact>
<contact>
<name>Bob</name>
<phoneNumbers>
<dial>4334553445</dial>
<dial>1001179212</dial>
<dial>6124456669</dial>
</phoneNumbers>
</contact>
</root>

Because an associative array won't allow me to create two ore more elements with the same key, and because (it appears) that I can only have one default element name, I have to choose between multiple <contact>s or multiple <dial> - but not both.

I solved the problem by using the XML functions built into PHP 5 - specifically the SimpleXML class, which doesn't require creating an array, and allows elements to be added line by line.