DataType Node

A DataType Node specifies the constraints for a literal value.

Key-value table

In the following the basic attributes that a DataType Node can have are listed:

key	required	value type	description	related error
sh:datatype	true	IRI	The XSD-IRI representing the datatype the value must have. Below are the mapping functions between schema.org datatypes and XSD datatypes	Non-conform range
sh:defaultValue	false	Literal	The standard value for this DataType (must be of the respective datatype). This is only a representational key-property (non-validating)

Example

{
  "@type": "sh:PropertyShape",
  "sh:path": "schema:address",
  "sh:or": [
    {
      "sh:datatype": "xsd:string",
      "sh:defaultValue": "Innsbruck 6020"
    }
  ]  
}

Advanced Constraints

Advanced constraints are introduced with this DS version. They can be used in DataType nodes for specific datatypes. Some of these constraints can have multiple entries; if that is the case, then an array is used to wrap the values.

See https://docs.google.com/spreadsheets/d/1AFD21lB_zQkns_3aeDLIFW1E-C36eJ3DogcnOb2vD7g/edit#gid=1009977856

Value Range Constraint Components

SHACL reference: https://www.w3.org/TR/shacl/#core-components-range

These constraint components dictate a value range that the value of a literal value must have. The datatype for this value must be the same as the datatype of the constrained literal. Datatypes that are allowed to have these constraints are: Date, DateTime, Time, Number, Float, and Integer.

key	value type	description	related error
sh:minExclusive	same as constrained Data Type	The minimum exclusive value that the value must have	Non-conform sh:minExclusive
sh:minInclusive	same as constrained Data Type	The minimum inclusive value that the value must have	Non-conform sh:minInclusive
sh:maxExclusive	same as constrained Data Type	The maximum exclusive value that the value must have	Non-conform sh:maxExclusive
sh:maxInclusive	same as constrained Data Type	The maximum inclusive value that the value must have	Non-conform sh:maxInclusive

Example:

{
    "sh:datatype": "xsd:integer",
    "sh:minExclusive": 0,
    "sh:maxInclusive": 10
}

{
    "sh:datatype": "xsd:date",
    "sh:minExclusive": "2010-10-10"
}

String based Constraint Components

SHACL reference: https://www.w3.org/TR/shacl/#core-components-string

These constraint components are meant for literals having the datatype string (and their sub-datatypes in some cases).

key	value type	description	related error
sh:maxLength	Integer	The maximum allowed string length of a literal (String or URL)	Non-conform sh:maxLength
sh:minLength	Integer	The minimum allowed string length of a literal (String or URL)	Non-conform sh:minLength
sh:pattern	[Regex]	A regular expression that the literal must match (String or URL)	Non-conform sh:pattern
sh:languageIn	[Language-Tag]	The literal must use a language tag given in the list of language tags (https://tools.ietf.org/html/bcp47) . Only for String values (in theory the exact datatype of the target literal is rdf:langString, but due to our Schema.org <-> XSD mapping we use xsd:string and allow a language tag for it)	Non-conform sh:languageIn
sh:uniqueLang	Boolean	The property sh:uniqueLang can be set to true to specify that no pair of value nodes may use the same language tag. (Array of values must have unique language tags). Only for String values (in theory the exact datatype of the target literal is rdf:langString, but due to our Schema.org <-> XSD mapping we use xsd:string and allow a language tag for it)	Non-conform sh:uniqueLang

Example of a DataType Node as range for schema:description:

{
    "sh:datatype": "xsd:string",
    "sh:minLength": 20,
    "sh:maxLength": 200,
    "sh:languageIn": [
      "en",
      "de"
    ],
    "sh:uniqueLang": true
}

Example of a DataType Node as range for schema:telephone:

{
  "sh:datatype": "xsd:string",
  "sh:pattern": [
    "^\\s*\\+?\\s*([0-9][\\s-]*){9,}$"
  ]
}

Property Value Pair Constraint Components

SHACL reference: https://www.w3.org/TR/shacl/#core-components-property-pairs

These constraints are explained in Property.md since they are expressed on a property-level, and not on a data-type-level.

Other Constraint Components

SHACL reference: https://www.w3.org/TR/shacl/#core-components-others

These constraints can be used on any data type.

key	value type	description	related error
sh:in	same as constrained Data Type	Specifies the condition that each value node is a member of a provided SHACL list	Non-conform sh:in
sh:hasValue	same as constrained Data Type	Specifies the condition that at least one value node is equal to the given value	Non-conform sh:hasValue

Example:

{
  "sh:path": "schema:City",
  "sh:or":[
    {
      "sh:datatype": "xsd:string",
      "sh:in": [
        "Innsbruck",
        "Wien",
        "Salzburg"
      ],
      "sh:hasValue": [
        "Innsbruck"
      ]
    }
  ]
}

Datatype Mapping

Mapping Functions between XSD datatypes and schema.org datatypes:

(Other datatypes are ignored for now, since they are not used in practice)

function schemaToXsd(dataType) {
    switch (dataType) {
        case "schema:Text":
            return "xsd:string";
        case "schema:Boolean":
            return "xsd:boolean";
        case "schema:Date":
            return "xsd:date";
        case "schema:DateTime":
            return "xsd:dateTime";
        case "schema:Time":
            return "xsd:time";
        case "schema:Number":
            return "xsd:double";
        case "schema:Float":
            return "xsd:float";
        case "schema:Integer":
            return "xsd:integer";
        case "schema:URL":
            return "xsd:anyURI";
    }
}
function xsdToSchema(dataType) {
    switch (dataType) {
        case "xsd:string":
            return "schema:Text";
        case "xsd:boolean" :
            return "schema:Boolean";
        case "xsd:date" :
            return "schema:Date";
        case "xsd:dateTime":
            return "schema:DateTime";
        case "xsd:time":
            return "schema:Time";
        case "xsd:double":
            return "schema:Number";
        case "xsd:float":
            return "schema:Float";
        case "xsd:integer":
            return "schema:Integer";
        case "xsd:anyURI":
            return "schema:URL";
    }
}