Design DataElement model and resolve naming collision

[matthewhorridge]

Problem

DataElement in src/harmonization_framework/element.py is a placeholder with only type annotations and no initialization, validation, or serialization. There is also a different DataElement ORM model in api/models.py, creating a naming collision.

Questions

• Should the core library use a dedicated, serializable DataElement model (e.g., dataclass/pydantic)?
• Should it reuse or mirror the API ORM model?
• What should be the stable identifier for DataElement (id/label/URI)?
• How do we align with the RADx Data Dictionary Spec for Data Elements?

Proposal

Define a real DataElement model with:

• explicit fields (id, label, type, enumerations)
• __eq__/__hash__ based on a stable id
• to_dict/from_dict for rule serialization

Also rename one of the DataElement classes or namespace it clearly to avoid confusion.

Files

• src/harmonization_framework/element.py
• src/harmonization_framework/api/models.py