Node reference properties [synonyms: extended relationship, widget, option]

For the image field you can associate additional data by image field extended. I am just searching for a possibility to do so for nodereference.

The goal is to give a node reference a more precise relationship. Instead of refering content type employee to content type company (or backward), I want to refer person to company with an additional field employee/exployer or customer.

My first workaround was to create seperate node reference fields. But this results in problems with data integration in views: http://drupal.org/node/1188148

So I am about to write a small module similar to image field extended. I allready tried to use multigroups which is one way to integrate data, but I donnot like the way multigroups renders data. Besides it is not supported in D7. Though it has the advantage to be able to use taxonomy to describe a relationship. Up to this point it is not clear if the relation module in D7 will to this job.

What do you think about an approch writing a small module extending data structure for node reference? Is there another more elegant alternative to set up attributes/properties/widgets for Node Reference or a CCK field? I would look at the structure of Image Field Extended for such a solution.

In a long term view a reference property should be also integrated in a back reference. Such an approach would extend the ability in Drupal to build complex structures ernourmous:

My ideal situation would be: A taxonomy property for node reference including a backrefence option without having to set up a new field in the referenced node type. The property data should be included in the field data to avoid extra fields to improve rendering flexibilty and loading time.