Open Source Document Management System | OpenKM

Hi Guys - had a look around the forums and it seems like the two ways to add metadata to documents is through property groups and if really simple - keywords.
My Question is - is there an easier way?

What I would've envisaged happening is that when you add a document you pick a document type from a drop down (eg Sales Invoice or Purchase Order).
If you set your document as a sales invoice - it would make available a set of metadata fields (eg. Sales Person, Client etc).
If you set your document as a Purchase Order - it would make available a set of metdata fields (eg. Supplier, Part Name etc).

In search - you could then say I want to search for this document type and it would allow you to input values into the fields - eg. Sales Person = Tom

Is there a feature that I'm missing in openKM - that does this?
I find property groups quite hard to work with. Also you optionally set them up against each document rather than making a document have a mandatory type.

You can enable wizard and include property groups there, after uploading file will demand metadata. We're working on some rules to indicate when must be added metadata but it'll be only available on next release.

Now could simulate it with events and scripting, if there's some logic to determine when a document is some type, and automatically set possible metadata. Automatic means must be written some logic in scripting or document event handlers.