Introduce n3

package.json

@@ -1,6 +1,6 @@
 {
   "name": "shacl-tulip",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "type": "module",
   "main": "./src/index.js",
   "module": "./src/index.js",
@@ -24,6 +24,6 @@
   "dependencies": {
     "@rdfjs/fetch-lite": "^3.3.0",
     "@rdfjs/formats-common": "^3.1.0",
-    "rdf-ext": "^2.5.2"
+    "n3": "^1.25.2"
   }
 }

src/classes/ClassDataset.js

@@ -15,8 +15,8 @@ export class ClassDataset extends RdfDataset {
         if (quad.predicate.value === RDFS.subClassOf.value &&
             quad.subject.termType !== 'BlankNode' &&
             quad.object.termType !== 'BlankNode' ) {
-            this.addQuad(quad)
-            this.dispatchEvent(new CustomEvent('quad', { detail: quad }));
+                this.addQuad(quad)
+                this.dispatchEvent(new CustomEvent('quad', { detail: quad }));
         }
     }
 }

src/classes/FormBase.js

@@ -2,9 +2,10 @@
  * 
  */
 
-import rdf from 'rdf-ext';
 import { RDF } from '../modules/namespaces';
 import { isEmptyObject, toIRI} from '../modules/utils';
+import { DataFactory } from 'n3';
+const { namedNode, blankNode, quad } = DataFactory;
 
 export class FormBase {
 
@@ -140,7 +141,7 @@ export class FormBase {
         // Identify the record's subject (named or blank node)
         var subject = this._getRecordSubjectTerm(subject_uri, this.content[class_uri][subject_uri])
         // Add the triple stating the subject is of type class
-        let firstQuad = rdf.quad(subject, rdf.namedNode(RDF.type.value), rdf.namedNode(class_uri))
+        let firstQuad = quad(subject, namedNode(RDF.type.value), namedNode(class_uri))
         quadArray.push(firstQuad)
         // Now we need to add all triples relating to the properties of the record.
         for (var triple_predicate of Object.keys(this.content[class_uri][subject_uri])) {
@@ -161,21 +162,21 @@ export class FormBase {
                 continue
             }
             // now set the predicate as a named node
-            var predicate = rdf.namedNode(triple_predicate)
+            var predicate = namedNode(triple_predicate)
             // In order to set the node type of the object, we first need to figure it out
             var [nodeFunc, dt] = shapesDS.getPropertyNodeKind(class_uri, triple_predicate, this.ID_IRI)
             // Now we can create the object nodes for each property
             for (var val of this.content[class_uri][subject_uri][triple_predicate]) {
                 // val: all values of a given property of an identifiable object
                 let triple_object
                 if (dt) {
-                    triple_object = nodeFunc(val, rdf.namedNode(dt))
+                    triple_object = nodeFunc(val, namedNode(dt))
                 } else {
                     triple_object = nodeFunc(val)
                 }
                 // and finally we can add the quads to the store
-                let quad = rdf.quad(subject, predicate, triple_object)
-                quadArray.push(quad)
+                let q = quad(subject, predicate, triple_object)
+                quadArray.push(q)
             }
         }
         return quadArray
@@ -202,9 +203,9 @@ export class FormBase {
         var subject
         if (Object.keys(record).indexOf(this.ID_IRI) >= 0) {
             var subject_iri = record[this.ID_IRI][0]
-            subject = rdf.namedNode(subject_iri)
+            subject = namedNode(subject_iri)
         } else {
-            subject = rdf.blankNode(record_id)
+            subject = blankNode(record_id)
         }
         return subject
     }
@@ -258,7 +259,7 @@ export class FormBase {
         if (this.content[class_uri]) {
             // If we are in edit mode, the first step is to delete existing quads from graphData
             if (editMode) {
-                RdfDS.data.graph.deleteMatches(rdf.namedNode(node_uri), null, null, null)
+                RdfDS.data.graph.deleteMatches(namedNode(node_uri), null, null, null)
             }
 
             // Then we generate the quads
@@ -285,9 +286,9 @@ export class FormBase {
             // - for each triple in oldTriples: create a new one with same subject and predicate
             //   and with new IRI as object, then delete the old triple
             if (editMode && subject_iri !== null && subject_iri !== node_uri) {
-                var objectQuads = RdfDS.getObjectTriples(rdf.namedNode(node_uri))
+                var objectQuads = RdfDS.getObjectTriples(namedNode(node_uri))
                 objectQuads.forEach((quad) => {
-                    let new_quad = rdf.quad(quad.subject, quad.predicate, subject)
+                    let new_quad = quad(quad.subject, quad.predicate, subject)
                     RdfDS.data.graph.delete(quad)
                     RdfDS.data.graph.add(new_quad)
                 });

src/classes/RdfDataset.js

@@ -1,8 +1,8 @@
-import rdf from 'rdf-ext';
 import { readRDF } from '../modules/io'
 import { RDF, XSD } from '../modules/namespaces';
 import { toCURIE } from '../modules/utils';
-import formatsPretty from '@rdfjs/formats/pretty.js'
+import { Store, Writer, DataFactory } from 'n3';
+const { namedNode, literal } = DataFactory;
 
 /**
  * A class wrapping an RDF dataset (quad-store) from the `rdf-ext` library.
@@ -13,8 +13,6 @@ export class RdfDataset {
      */
     constructor(data = {}) {
         this.data = data;
-        this.rdfPretty = rdf.clone();
-        this.rdfPretty.formats.import(formatsPretty);
         this.data.prefixes = {};
         this.data.serializedGraph = '';
         this.data.graphLoaded = false;
@@ -37,11 +35,11 @@ export class RdfDataset {
 
     /**
      * Create a quad store compliant with the [RDF/JS dataset specification](https://rdf.js.org/dataset-spec/)
-     * via the `rdf-ext` package
-     * @returns {import("rdf-ext").DatasetCore} The RDF dataset instance.
+     * via the `n3` package
+     * @returns {} The RDF dataset instance.
      */
     createDataset() {
-        return rdf.dataset()
+        return new Store();
     }
     /**
      * Loads RDF data from a given URL and processes prefixes and quads.
@@ -60,16 +58,14 @@ export class RdfDataset {
         // Load prefixes
         quadStream.on('prefix', (prefix, ns) => {
             this.onPrefixFn(prefix, ns)
+        }).on('data', quad => {
+            this.onDataFn(quad)
         }).on('end', () => {
+            this.onDataEndFn()
             this.onPrefixEndFn()
-        })
-        // Load data
-        quadStream.on('data', quad => {
-            this.onDataFn(quad)
-        }).on('end', async () => {
-            await this.onDataEndFn()
+        }).on('error', err => {
+            console.error('Error while processing quadStream:', err);
         });
-
         return result
     }
 
@@ -83,7 +79,7 @@ export class RdfDataset {
     /**
      * Process an RDF prefix.
      * @param {string} prefix - The prefix string.
-     * @param {import("rdf-ext").NamedNode} ns - The namespace associated with the prefix.
+     * @param {} ns - The namespace associated with the prefix.
      */
     onPrefixFn(prefix, ns) {
         this.data.prefixes[prefix] = ns.value;
@@ -96,63 +92,65 @@ export class RdfDataset {
 
     /**
      * Process an RDF quad
-     * @param {import("rdf-ext").Quad} quad - The RDF quad.
+     * @param {} quad - The RDF quad.
      */
     onDataFn(quad) {
         // The first following line, moved here from shacl-vue's graphdata composable,
         // was an attempt to solve https://hub.datalad.org/datalink/annotate-trr379-demo/issues/32.
         // But it was a faulty attempt, since the object was different. Still, leaving it here since
         // deleting matches would prospectively solve the duplication of named node or literal objects
-        this.data.graph.deleteMatches(quad.subject, quad.predicate, quad.object, null)
+        // this.data.graph.removeMatches(quad.subject, quad.predicate, quad.object, null)
         this.addQuad(quad)
         this.dispatchEvent(new CustomEvent('quad', { detail: quad }));
     }
-    async onDataEndFn() {
-        await this.updateSerializedGraph()
+
+    onDataEndFn() {
         this.data.graphLoaded = true
         this.dispatchEvent(new CustomEvent('graphLoaded', { detail: this.data.graph }));
     }
 
     /**
      * Add an RDF quad to the dataset
-     * @param {import("rdf-ext").Quad} quad - The RDF quad to add.
+     * @param {} quad - The RDF quad to add.
      */
     addQuad(quad) {
-        this.data.graph.add(quad)
+        this.data.graph.addQuad(quad)
     }
 
     /**
      * Serializes the RDF graph to Turtle format.
      * @returns {Promise<string>} The serialized RDF graph in Turtle format.
      */
     async serializeGraph() {
-        return (await this.rdfPretty.io.dataset.toText('text/turtle', this.data.graph)).trim()
-    }
-
-    async updateSerializedGraph() {
-        this.data.serializedGraph = (await this.rdfPretty.io.dataset.toText('text/turtle', this.data.graph)).trim()
+        // Using N3.Writer to serialize graph to Turtle
+        return new Promise((resolve, reject) => {
+            const writer = new Writer({ prefixes: this.data.prefixes });
+            writer.addQuads(this.data.graph.getQuads(null, null, null, null));
+            writer.end((error, result) => {
+                if (error) reject(error);
+                else resolve(result.trim());
+            });
+        });
     }
 
     /**
      * Checks if a given RDF node represents an RDF list.
-     * @param {import("rdf-ext").Term} node - The RDF node to check.
+     * @param {} node - The RDF node to check.
      * @returns {boolean} True if the node represents an RDF list, otherwise false.
      */
     isRdfList(node) {
         let hasFirst = false;
         let hasRest = false;
-        this.data.graph.forEach((quad) => {
-            if (quad.subject.equals(node)) {
-                if (quad.predicate.value === RDF.first.value) hasFirst = true;
-                if (quad.predicate.value === RDF.rest.value) hasRest = true;
-            }
+        this.data.graph.getQuads(node, null, null, null).forEach((quad) => {
+            if (quad.predicate.value === RDF.first.value) hasFirst = true;
+            if (quad.predicate.value === RDF.rest.value) hasRest = true;
         });
         return hasFirst && hasRest;
     };
 
     /**
      * Converts an RDF list to an array.
-     * @param {import("rdf-ext").Term} startNode - The starting node of the RDF list.
+     * @param {} startNode - The starting node of the RDF list.
      * @returns {Array} The converted RDF list as an array.
      */
     rdfListToArray(startNode) {
@@ -161,79 +159,55 @@ export class RdfDataset {
         while (currentNode && currentNode.value !== RDF.nil.value) {
             let listItem = null;
             // Get the first element in the RDF list
-            this.data.graph.forEach((quad) => {
-                if (quad.subject.equals(currentNode) && quad.predicate.value === RDF.first.value) {
-                    // Resolve blank nodes recursively, but handle literals and IRIs separately
-                    if (quad.object.termType === "BlankNode") {
-                        listItem = this.resolveBlankNode(quad.object, this.data.graph);
-                    } else if (quad.object.termType === "Literal") {
-                        listItem = quad.object.value; // Store literal value
-                    } else if (quad.object.termType === "NamedNode") {
-                        listItem = quad.object.value; // Store IRI as a string
+            this.data.graph.getQuads(currentNode, RDF.first, null, null).forEach(quad => {
+                if (quad.object.termType === 'BlankNode') {
+                    if (this.isRdfList(quad.object)) {
+                        listItem = this.rdfListToArray(quad.object);
+                    } else {
+                        listItem = this.resolveBlankNode(quad.object);
                     }
+                } else if (quad.object.termType === 'Literal' || quad.object.termType === 'NamedNode') {
+                    listItem = quad.object.value;
                 }
             });
             if (listItem !== null) {
                 listItems.push(listItem);
             }
             // Move to the next item in the list (rdf:rest)
-            let nextNode = null;
-            this.data.graph.forEach((quad) => {
-                if (quad.subject.equals(currentNode) && quad.predicate.value === RDF.rest.value) {
-                    nextNode = quad.object;
-                }
-            });
-            currentNode = nextNode;
+            const restQuads = this.data.graph.getQuads(currentNode, RDF.rest, null, null);
+            currentNode = restQuads.length > 0 ? restQuads[0].object : null;
         }
         return listItems;
     };
 
     resolveBlankNode(blankNode) {
         let resolvedObject = {};
-        this.data.graph.forEach((quad) => {
-            if (quad.subject.equals(blankNode)) {
-                const predicate = quad.predicate.value;
-                const object = quad.object;
-
-                // If the object is a blank node, resolve it recursively
-                if (object.termType === "BlankNode") {
-                    // Check if it's an RDF list and convert it to an array
-                    if (this.isRdfList(object)) {
-                        resolvedObject[predicate] = this.rdfListToArray(object);
-                    } else {
-                        resolvedObject[predicate] = this.resolveBlankNode(object);
-                    }
-                } else if (object.termType === "Literal") {
-                    resolvedObject[predicate] = object.value; // Handle literal values
-                } else if (object.termType === "NamedNode") {
-                    resolvedObject[predicate] = object.value; // Handle IRIs as strings
+        this.data.graph.getQuads(blankNode, null, null, null).forEach(({ predicate, object }) => {
+            if (object.termType === 'BlankNode') {
+                if (this.isRdfList(object)) {
+                    resolvedObject[predicate.value] = this.rdfListToArray(object);
+                } else {
+                    resolvedObject[predicate.value] = this.resolveBlankNode(object);
                 }
+            } else if (object.termType === 'Literal' || object.termType === 'NamedNode') {
+                resolvedObject[predicate.value] = object.value;
             }
         });
         return resolvedObject;
     }
 
     getLiteralAndNamedNodes(predicate, propertyClass, prefixes) {
         var propClassCurie = toCURIE(propertyClass, prefixes)
-        // a) use the literal node with xsd data type
-        const literalNodes = rdf.grapoi({ dataset: this.data.graph })
-            .hasOut(predicate, rdf.literal(String(propClassCurie), XSD.anyURI))
-            .quads();
-        // b) and the named node
-        const uriNodes = rdf.grapoi({ dataset: this.data.graph })
-            .hasOut(predicate, rdf.namedNode(propertyClass))
-            .quads();
-        // return as a concatenated array of quads
-        return Array.from(literalNodes).concat(Array.from(uriNodes))
+        const literalQuads = this.data.graph.getQuads(null, predicate, literal(String(propClassCurie), XSD.anyURI), null)
+        const uriQuads = this.data.graph.getQuads(null, predicate, namedNode(propertyClass), null)
+        return literalQuads.concat(uriQuads)
     }
 
     getSubjectTriples(someTerm) {
-        const quads = rdf.grapoi({ dataset: this.data.graph, term: someTerm }).out().quads();
-        return Array.from(quads)
+        return this.data.graph.getQuads(someTerm, null, null, null);
     }
 
     getObjectTriples(someTerm) {
-        const quads = rdf.grapoi({ dataset: this.data.graph, term: someTerm }).in().quads();
-        return Array.from(quads)
+        return this.data.graph.getQuads(null, null, someTerm, null);
     }
 }