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X Rules

SHACL-X allows to define new rules types that are X-based.

Rule Type IRI Key Property Other Properties
sh:JSRule sh:jsFunctionName sh:jsLibrary
sh:PyRule sh:pyFunctionName sh:pyLibrary

An Example of an X rule

The following example illustrates the use of a X rule to compute the area of a rectangle, by multiplying width and height.

Example data graph

ex:ExampleRectangle
    a ex:Rectangle ;
    ex:width 7 ;
    ex:height 8 .

Example shapes graph

ex:RectangleShape
a sh:NodeShape ;
sh:targetClass ex:Rectangle ;
sh:rule [
    a sh:JSRule ;
    sh:jsFunctionName "computeArea" ;
    sh:jsLibrary [ sh:jsLibraryURL "http://example.org/js/rectangle.js"^^xsd:anyURI ] ;
] .

ex:RectangleShape
a sh:NodeShape ;
sh:targetClass ex:Rectangle ;
sh:rule [
    a sh:PyRule ;
    sh:pyFunctionName "compute_area" ;
    sh:pyLibrary [ sh:pyLibraryURL "http://example.org/py/rectangle.py"^^xsd:anyURI ] ;
] .

Example X rule

let NS = "http://datashapes.org/js/tests/rules/rectangle.test#";

function computeArea($this) {
    let width = getProperty($this, "width");
    let height = getProperty($this, "height");
    let area = TermFactory.literal(width.getLex() * height.getLex(), width.getDatatype());
    let areaProperty = TermFactory.namedNode(NS + "area");
    return [ [$this, areaProperty, area] ]; 
}

function getProperty($this, name) {
    let it = $data.find($this, TermFactory.namedNode(NS + name), null);
    let result = it.next().getObject();
    it.close();
    return result;
}

ns = "http://datashapes.org/py/tests/rules/rectangle.test#"


def compute_area(_this):
    width = get_property(_this, "width")
    height = get_property(_this, "height")
    area = py_tf.literal(int(width.getLex()) * int(height.getLex()), width.getDatatype())
    area_property = py_tf.namedNode(ns + "area")
    return [ [_this, area_property, area] ]


def get_property(_this, name):
    it = _data.find(_this, py_tf.namedNode(ns + name), None)
    result = it.next().getObject()
    it.close()
    return result

Example inferred triples

ex:ExampleRectangle ex:area 56 .