Layered COLLADA Loader for OpenGL3.1+ Context

Question

What layers would aid in implementing this efficiently? Preferably such that I am able to get these three components listed below up with the early layers and code the rest as I go.

I am writing a COLLADA loading library to use with my graphics engine. So of course as soon as I began I notice this seems to be a rather large task. I now intend to write the library to use different layers.

I do not yet understand COLLADA. I'm assuming there may be:

• Geometry layer
• Shader layer
• Texure Layer

Even these I'm unsure of, may need to be part of a different sort of layering scheme.

Side note, I will most likely be using irrXML or this interesting XML library I just read about here to read the files unless advised otherwise.