SDO Enumeration

JSON Syntax of DS-V1

A dsv:RestrictedEnumeration node appears as value for the dsv:expectedType property of a dsv:Property node. The enumeration consists of the dsv:RestrictedEnumeration object that specifies the enumeration class, and the valid enumeration members that are listed in the array of dsv:expectedEnumerationValue.

{
  "@type": "dsv:Property",
  "dsv:baseProperty": {
    "@id": "schema:dayOfWeek"
  },
  "dsv:expectedType": [
    {
      "@type": "dsv:RestrictedEnumeration",
      "dsv:baseEnumeration": {
        "@id": "schema:DayOfWeek"
      },
      "dsv:expectedEnumerationValue": [
        {
          "@type": "dsv:EnumerationValue",
          "@id": "schema:Sunday"
        },
        {
          "@type": "dsv:EnumerationValue",
          "@id": "schema:Thursday"
        }
      ]
    }
  ]
}

SHACL JSON-LD Syntax of DS-V3

sh:class is used to specify the expected enumeration type (e.g. schema:DayOfWeek). Note that since a normal type also uses sh:class, the software interpreting the DS must be able to differentiate types from enumerations. sh:in CAN be used to specify the set of allowed enumeration members for that enumeration type (e.g. schema:Sunday, schema:Monday, etc.). If sh:in it not given, then any enumeration member of the target enumeration type is allowed (see second example). If the enumeration has no enumeration members (happens in Schema.org ...) the enumeration value is valid, as long as it is a URI.

Example uses @context of context.md

{
  "@type": "sh:PropertyShape",
  "sh:path": "schema:dayOfWeek",
  "sh:class": "schema:DayOfWeek",
  "sh:in": {
    "@list": [
      "schema:Sunday",
      "schema:Thursday"
    ]
  }
}

{
  "@type": "sh:PropertyShape",
  "sh:path": "schema:dayOfWeek",
  "sh:class": "schema:DayOfWeek"
}

Target Annotation structure (JSON-LD)

This is a Schema.org annotation that is valid for the previous enumeration constraint. This example uses a "correct and complete" JSON-LD syntax.

{
  "@context": {
    "@vocab": "http://schema.org/"
  },
  "@type": "OpeningHoursSpecification",
  "dayOfWeek": {
    "@id": "http://schema.org/Thursday",
    "@type": "http://schema.org/DayOfWeek"
  }
}

Expected Annotation structure (JSON-LD)

This annotation shows a simplified syntax (how it is used in the wild) for the previous example Schema.org annotation. This syntax is usually not enough to be processed by a SHACL validator for the previous enumeration constraint example, however our validation tool should be able to interpret/validate it.

{
  "@context": "http://schema.org/",
  "@type": "OpeningHoursSpecification",
  "dayOfWeek": "http://schema.org/Thursday"
}