Enforcing domain invariants

[blelump]

Problem overview

There are cases to ensure consistency and integrity of the underlying data model to execute more sophisticated rules on the data itself. They are not supported by OCA in any way, among other things:

• each entity has a unique ID number
• check digit meets an identification number
• device type X has ABC additionally built-in, whereas Y does not

What's the DSWG's perspective on the above business rules, and what is the best place to enforce them? In particular, whether it is still OCA scope.

[pknowl]

@blelump Is this the type of overlay you are thinking of for an Invariant Overlay?

{
  "capture_base":"EuQXuO3q0Bbgb_h4RgE37xRvdDXqoYZpFIApL7gUMc0g",
  "digest":"EAKY23aWiy2WSij7R5L0teOsUj35tZiaUOE89d4oi62s",
  "type":"spec/overlays/invariant/1.0",
  "attribute_invariants":{
    "age":"1 <= age <= 125",
    "gender":"gender in ['M', 'F', 'X']",
    "membershipType":"membershipType in ['PREM', 'BASC']",
    "email":"regex('[\\w.-]+@[\\w.-]+\\.\\w+')",
    "registrationDate":"registrationDate <= currentDate()",
    "isActive":"isActive in [0, 1]",
    "profileImage":"profileImage format is 'image/jpeg' or profileImage is absent",
    "interests":"all interests in ['HIKE', 'READ', 'COOK', 'MUSC', 'TRVL', 'SPRT'] and no duplicates"
  }
}

If so, feel free to edit the code snippet as we can use it in an associated RFC