feat: added transform for skolem-iris

bin/rdf-ext-cli.js

@@ -9,6 +9,7 @@ import createInputStream from '../lib/createInputStream.js'
 import createOutputStream from '../lib/createOutputStream.js'
 import createShaclStream from '../lib/createShaclStream.js'
 import transformMapNamespaceFunc from '../lib/transformMapNamespace.js'
+import transformSkolemIrisFunc from '../lib/transformSkolemIris.js'
 import transformToTripleFunc from '../lib/transformToTriple.js'
 
 const program = new Command()
@@ -42,6 +43,7 @@ program
   .option('--shacl-details', 'generate nested result details')
   .option('--shacl-trace', 'generate results for path traversing')
   .option('--transform-map-namespace <mapping>', 'map the given namespaces', collectMappings, rdf.termMap())
+  .option('--transform-skolem-iris <baseIri>', 'map blank nodes to Skolem IRIs')
   .option('--transform-to-triples', 'set graph to default graph')
   .option('--output-prefix <prefix>', 'output prefix', collectPrefixes, new Map())
   .option('--output-type <type>', 'output content type', 'text/turtle')
@@ -58,6 +60,7 @@ program
     shaclDetails,
     shaclTrace,
     transformMapNamespace,
+    transformSkolemIris,
     transformToTriple,
     outputPrefix,
     outputType,
@@ -104,6 +107,13 @@ program
       stream = toTripleStream
     }
 
+    if (transformSkolemIris) {
+      const toTripleStream = transformSkolemIrisFunc(transformSkolemIris)
+
+      stream.pipe(toTripleStream)
+      stream = toTripleStream
+    }
+
     if (transformToTriple) {
       const toTripleStream = transformToTripleFunc()
 

examples/url-to-skolem-iri-turtle.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+./bin/rdf-ext-cli.js \
+  --pretty \
+  --transform-skolem-iris http://example.com/.well-known/genid/ \
+  --output-prefix houseplace=https://housemd.rdf-ext.org/place/ \
+  --output-prefix schema=http://schema.org/ \
+  https://housemd.rdf-ext.org/place/221b-baker-street

lib/transformSkolemIris.js

@@ -0,0 +1,37 @@
+import { randomUUID } from 'node:crypto'
+import rdf from 'rdf-ext'
+import { Transform } from 'readable-stream'
+
+function transformSkolemIris (baseIri) {
+  const nodeMap = rdf.termMap()
+
+  const mapTerm = term => {
+    if (term.termType === 'BlankNode') {
+      if (!nodeMap.has(term)) {
+        nodeMap.set(term, rdf.namedNode(`${baseIri}${randomUUID().split('-').join('')}`))
+      }
+
+      return nodeMap.get(term)
+    }
+
+    return term
+  }
+
+  const mapQuad = quad => {
+    return rdf.quad(
+      mapTerm(quad.subject),
+      mapTerm(quad.predicate),
+      mapTerm(quad.object),
+      mapTerm(quad.graph)
+    )
+  }
+
+  return new Transform({
+    objectMode: true,
+    transform: (quad, encoding, callback) => {
+      callback(null, mapQuad(quad))
+    }
+  })
+}
+
+export default transformSkolemIris