Update spec to support node expressions in sh:node

Author: mgberg

shacl12-core/index.html

@@ -2520,6 +2520,7 @@ <h2>Node Expressions</h2>
 			<ul>
 				<li>At <a href="#property-shapes"><code>sh:values</code> and <code>sh:defaultValue</code></a> to derive the value nodes of a property shape.</li>
 				<li>At <a href="#targetNode"><code>sh:targetNode</code></a> to dynamically compute the targets of a shape.</li>
+				<li>At <a href="#NodeConstraintComponent"><code>sh:node</code></a> to validate nodes against a dynamically computed set of node shapes.</li>
 				<li>At <a href="#ExpressionConstraintComponent"><code>sh:expression</code></a> to validate nodes against a condition.</li>
 				<li>At <a href="#deactivated"><code>sh:deactivated</code></a> to deactivate certain shapes under specific conditions.</li>
 			</ul>
@@ -5380,7 +5381,10 @@ <h3>Shape-based Constraint Components</h3>
 				<section id="NodeConstraintComponent">
 					<h4>sh:node</h4>
 					<p>
-						<code>sh:node</code> specifies the condition that each <a>value node</a> conforms to the given <a>node shape</a>.
+						<code>sh:node</code> specifies the condition that each <a>value node</a> conforms to the
+						<a>node shapes</a> produced by a <a>node expression</a>.
+						The evaluation of these node expressions is repeated for all <a>value nodes</a> of the <a>shape</a>
+						as the <a>focus node</a>.
 					</p>
 					<p>
 						<span class="component-class">Constraint Component IRI</span>: <code>sh:NodeConstraintComponent</code>
@@ -5395,19 +5399,20 @@ <h4>sh:node</h4>
 						<tr>
 							<td><code>sh:node</code></td>
 							<td>
-								The <a>node shape</a> that all value nodes need to conform to.
-								<span data-syntax-rule="node-node">The values of <code>sh:node</code> in a shape must be <a>well-formed</a> <a>node shapes</a>.</span>
+								The <a>node shapes</a> that all value nodes need to conform to.
+								<span data-syntax-rule="node-node">The <a>values</a> of <code>sh:node</code> in a shape must be <a>well-formed</a> <a>node expressions</a>.</span>
 							</td>
 						</tr>
 					</table>
 					<div class="def def-text">
 						<div class="def-header">TEXTUAL DEFINITION</div>
 						<div class="def-text-body" data-validator="Node">
-							Let <code>$node</code> be a <a>value</a> of <code>sh:node</code>.
-							For each <a>value node</a> <code>v</code>:
-							A <a>failure</a> MUST be produced if the <a>conformance checking</a> of <code>v</code> against <code>$node</code> produces a <a>failure</a>.
-							Otherwise, if <code>v</code> does not <a>conform</a> to <code>$node</code>,
-							there is a <a>validation result</a> with <code>v</code> as <code>sh:value</code>.
+							Let <code>$expr</code> be a <a>value</a> of <code>sh:node</code>.
+							For each <a>value node</a> <code>v</code>: perform <a>conformance checking</a> of <code>v</code> against each <a>output node</a>
+							of <code>evalExpr(expr, <a>data graph</a>, v, {})</code> <code>s</code> that is a <a>node shape</a> in the <a>shapes graph</a>.
+							For each conformance check, a <a>failure</a> MUST be produced if the <a>conformance checking</a> of <code>v</code> against <code>s</code> produces a <a>failure</a>.
+							Otherwise, if <code>v</code> does not <a>conform</a> to <code>s</code>,
+							there is a <a>validation result</a> with <code>v</code> as <code>sh:value</code> and a <a>deep copy</a> of <code>s</code> as <code>sh:sourceConstraint</code>.
 						</div>
 					</div>
 					<p><em>The remainder of this section is informative.</em></p>
@@ -5534,6 +5539,7 @@ <h4>sh:node</h4>
 		sh:resultPath ex:address ;
 		sh:value ex:RetosAddress ;
 		sh:resultMessage "Value does not conform to shape ex:AddressShape." ;
+		sh:sourceConstraint ex:AddressShape ;
 		sh:sourceConstraintComponent sh:NodeConstraintComponent ;
 		sh:sourceShape _:b1 ;
 	]
@@ -5558,6 +5564,9 @@ <h4>sh:node</h4>
 		"sh:resultSeverity": {
 			"@id": "sh:Violation"
 		},
+		"sh:sourceConstraint": {
+			"@id": "ex:AddressShape"
+		},
 		"sh:sourceConstraintComponent": {
 			"@id": "sh:NodeConstraintComponent"
 		},
@@ -6864,7 +6873,7 @@ <h2>Revision History</h2>
 		<section class="appendix informative" id="changes-12">
 			<h2>Changes between SHACL 1.0 Core and SHACL 1.2 Core</h2>
 			<ul>
-				<li>Introduced <a>node expressions</a> as an extension point to dynamically compute lists of nodes. Generalized <code>sh:targetNode</code>, <code>sh:deactivated</code> and <code>sh:defaultValue</code>, and introduced <code>sh:values</code> to support node expressions.</li>
+				<li>Introduced <a>node expressions</a> as an extension point to dynamically compute lists of nodes. Generalized <code>sh:targetNode</code>, <code>sh:node</code>, <code>sh:deactivated</code> and <code>sh:defaultValue</code>, and introduced <code>sh:values</code> to support node expressions.</li>
 				<li>Added the new constraint component <a href="#SingleLineConstraintComponent"><code>sh:singleLine</code></a>, see <a href="https://github.com/w3c/data-shapes/issues/177">Issue 177</a></li>
 				<li>Added the new class <a href="#ShapeClass"><code>sh:ShapeClass</code></a> for implicit class targets, see <a href="https://github.com/w3c/data-shapes/issues/212">Issue 212</a></li>
 				<li>Moved SPARQL-based validators from Core to an Appendix of SHACL-SPARQL, see <a href="https://github.com/w3c/data-shapes/issues/271">Issue 271</a></li>