offset and stride

I have almost end my collada importer.
only …I not understand how know the offsets and stride before that import the geometry.
I search a lot on google but nothing.
How retrieve with collada dom the stride and the offsets?

COLLADA DOM project and docs is locate at sourceforge.

The COLLADA Refinery is another project that uses the DOM and you should be able to look at the source code to one of its geometry or animation conditioners to see how sources are accessed using the DOM’s API.