Promoting document metadata from xml

Question

Is there a way to promote document metadata from XML input?
MSDN states it's possible and that there's ever an XML built-in parser in place. However, after hours of searching the web I still don't know how to do this in practice.

As metadata promotion, I understand having an XML document of such structure, that updating the document will automagically update the proper metadata defined for the SP document it will become.

Answer 1

I managed to find a working solution. The information about the mapping from XPath to a concrete document property is stored inside a custom content type like this:

<FieldRef ID="{89E6F656-D104-4DBF-8795-8D6CA44DB1A9}" Name="D_TopicsUsed" Node="//map/topicref/@href" Aggregation="merge"/>

Then, to have the parser working for an uploaded XML file, two conditions must be met:

1. The file must be of XML extension.
2. Inside the file there must be the information for the parser, telling it which Sharepoint content type we are referencing: <?MicrosoftWindowsSharePointServices ContentTypeID="0x0101007438f6c6e5834860a94a8284a8c7106c"?>