@zazuko/query-rdf-data-cube - npm Package Compare versions

Comparing version 0.0.2 to 0.0.3

CHANGELOG.md

@@ -0,1 +1,27 @@
+<a name="0.0.3"></a>
+## [0.0.3](https://github.com/zazuko/query-rdf-data-cube/compare/v0.0.2...v0.0.3) (2019-09-09)
+
+
+### Bug Fixes
+
+* **datacube:** querying dataset by IRI does not fetch all datasets ([7ba4936](https://github.com/zazuko/query-rdf-data-cube/commit/7ba4936))
+* **dataset:** #graphs only return graphs related to a dataset ([7df53f5](https://github.com/zazuko/query-rdf-data-cube/commit/7df53f5))
+* **dataset:** graphIri is a string, not a namedNode ([2ec850c](https://github.com/zazuko/query-rdf-data-cube/commit/2ec850c))
+* **lang:** labels default to '' instead of defaulting to an IRI ([a7a37f7](https://github.com/zazuko/query-rdf-data-cube/commit/a7a37f7))
+* **query:** binding/comp maps use Map interface ([4979630](https://github.com/zazuko/query-rdf-data-cube/commit/4979630))
+* **query:** orderBy is always taken into account ([b0b0eb5](https://github.com/zazuko/query-rdf-data-cube/commit/b0b0eb5))
+
+
+### Features
+
+* **component:** components can have one label per language ([9b659be](https://github.com/zazuko/query-rdf-data-cube/commit/9b659be))
+* **cube:** implement languages for datasets fetching ([e1411a2](https://github.com/zazuko/query-rdf-data-cube/commit/e1411a2))
+* **datacube:** fetch datasets by an IRI or a graph IRI ([42f67b2](https://github.com/zazuko/query-rdf-data-cube/commit/42f67b2))
+* **dataset:** datasets can have one label per language ([edd7879](https://github.com/zazuko/query-rdf-data-cube/commit/edd7879))
+* **lang:** dataset passes down lang info to queries ([ea9bf11](https://github.com/zazuko/query-rdf-data-cube/commit/ea9bf11))
+* **query:** get labels with language preferences ([1602a43](https://github.com/zazuko/query-rdf-data-cube/commit/1602a43))
+* **serialization:** implement #toJSON and .fromJSON ([04d0e39](https://github.com/zazuko/query-rdf-data-cube/commit/04d0e39))
+
+
+
 <a name="0.0.2"></a>
@@ -2,0 +28,0 @@ ## 0.0.2 (2019-09-04)

dist/es/components/component.d.ts

 import { Term } from "rdf-js";
+import { Label } from "../dataset";
 import BaseExpr from "../expressions/base";
 import { IExpr } from "../expressions/utils";
 declare class Component extends BaseExpr {
-    label: Term;
+    /**
+     * Deserializes a Component from JSON generated by Component#toJSON
+     */
+    static fromJSON(json: string): Component;
+    labels: Label[];
     iri: Term;
@@ -11,6 +16,11 @@ aggregateType: string;
     componentType: string;
-    constructor({ label, iri }: {
-        label: string | Term;
+    constructor({ labels, iri }: {
+        labels: Label[];
         iri: string | Term;
     });
+    /**
+     * Serializes a Component to JSON in a way that makes it deserializable
+     * by calling Component#fromJSON
+     */
+    toJSON(): string;
     clone(): any;
@@ -17,0 +27,0 @@ avg(): any;

dist/es/components/component.js

@@ -1,6 +0,7 @@
-import { literal, namedNode } from "@rdfjs/data-model";
+import { namedNode } from "@rdfjs/data-model";
+import clone from "clone";
 import BaseExpr from "../expressions/base";
 import Binding from "../expressions/binding";
 class Component extends BaseExpr {
-    constructor({ label, iri }) {
+    constructor({ labels, iri }) {
         super();
@@ -10,8 +11,3 @@ this.isDistinct = false;
         this.componentType = "";
-        if (typeof label === "string") {
-            this.label = literal(label);
-        }
-        else {
-            this.label = label;
-        }
+        this.labels = labels || [];
         if (typeof iri === "string") {
@@ -24,5 +20,33 @@ this.iri = namedNode(iri);
     }
+    /**
+     * Deserializes a Component from JSON generated by Component#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        obj.iri = namedNode(obj.iri);
+        switch (obj.componentType) {
+            case "measure":
+                return new Measure(obj);
+            case "dimension":
+                return new Dimension(obj);
+            case "attribute":
+                return new Attribute(obj);
+        }
+        throw new Error(`Unknown component type '${obj.componentType}'`);
+    }
+    /**
+     * Serializes a Component to JSON in a way that makes it deserializable
+     * by calling Component#fromJSON
+     */
+    toJSON() {
+        const obj = {
+            componentType: this.componentType,
+            iri: this.iri.value,
+            labels: this.labels,
+        };
+        return JSON.stringify(obj);
+    }
     clone() {
         const Constructor = Object.getPrototypeOf(this).constructor;
-        const state = { label: this.label, iri: this.iri };
+        const state = { labels: clone(this.labels), iri: this.iri };
         const instance = new Constructor(state);
@@ -53,2 +77,5 @@ instance.aggregateType = this.aggregateType;
 export default Component;
+import Attribute from "./attribute";
+import Dimension from "./dimension";
+import Measure from "./measure";
 //# sourceMappingURL=component.js.map

dist/es/datacube.d.ts

 import { NamedNode } from "rdf-js";
 import DataSet from "./dataset";
+export interface ICubeOptions {
+    languages?: string[];
+}
 export declare class DataCube {
+    /**
+     * Deserializes a DataCube from JSON generated by DataCube#toJSON
+     */
+    static fromJSON(json: string): DataCube;
     private endpoint;
+    private languages;
     private fetcher;
     private cachedDatasets;
-    private datasetsLoaded;
+    private allDatasetsLoaded;
     private cachedGraphs;
     private graphsLoaded;
     /**
+     * A DataCube queries a SPARQL endpoint and retrieves [[DataSet]]s and
+     * their [[Dimension]]s, [[Measure]]s and [[Attribute]]s.
+     * @class DataCube
      * @param endpoint SPARQL endpoint
+     * @param options Options
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
+     * Passed down to [[DataSet]]s and [[DataSetQuery]].
      */
-    constructor(endpoint: string);
+    constructor(endpoint: string, options?: ICubeOptions);
     /**
+     * Serializes a DataCube to JSON in a way that makes it deserializable
+     * by calling DataCube#fromJSON
+     */
+    toJSON(): string;
+    /**
      * Fetch all [[DataSet]]s from the endpoint.
@@ -19,5 +38,19 @@ */
     /**
+     * Fetch a [[DataSet]] by its IRI.
+     *
+     * @param iri IRI of the DataSet to return.
+     */
+    datasetByIri(dataSetIri: string): Promise<DataSet>;
+    /**
+     * Fetch [[DataSet]]s by their graph IRI.
+     *
+     * @param graphIri IRI of the graph to look for in all DataSets.
+     */
+    datasetsByGraphIri(iri: string): Promise<DataSet[]>;
+    /**
      * Fetch all graphs from the endpoint.
      */
     graphs(): Promise<NamedNode[]>;
+    private cacheDatasets;
+    private generateQuery;
 }

dist/es/datacube.js

@@ -0,37 +1,108 @@
+import { namedNode, variable } from "@rdfjs/data-model";
+import { Generator as SparqlGenerator } from "sparqljs";
 import DataSet from "./dataset";
+import { generateLangCoalesce, generateLangOptionals, prefixes } from "./query/utils";
 import SparqlFetcher from "./sparqlfetcher";
 export class DataCube {
     /**
+     * A DataCube queries a SPARQL endpoint and retrieves [[DataSet]]s and
+     * their [[Dimension]]s, [[Measure]]s and [[Attribute]]s.
+     * @class DataCube
      * @param endpoint SPARQL endpoint
+     * @param options Options
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
+     * Passed down to [[DataSet]]s and [[DataSetQuery]].
      */
-    constructor(endpoint) {
-        this.datasetsLoaded = false;
+    constructor(endpoint, options = {}) {
+        this.allDatasetsLoaded = false;
         this.graphsLoaded = false;
         this.endpoint = endpoint;
+        this.languages = options.languages || ["de", "it"];
         this.fetcher = new SparqlFetcher(endpoint);
-        this.cachedDatasets = [];
+        this.cachedDatasets = new Map();
         this.cachedGraphs = [];
     }
     /**
+     * Deserializes a DataCube from JSON generated by DataCube#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        const datacube = new DataCube(obj.endpoint, {
+            languages: obj.languages,
+        });
+        datacube.cachedDatasets = obj.datasets.reduce((map, str) => {
+            const dataset = DataSet.fromJSON(str);
+            map.set(dataset.iri, dataset);
+            return map;
+        }, new Map());
+        return datacube;
+    }
+    /**
+     * Serializes a DataCube to JSON in a way that makes it deserializable
+     * by calling DataCube#fromJSON
+     */
+    toJSON() {
+        const obj = {
+            endpoint: this.endpoint,
+            languages: this.languages,
+            datasets: Array.from(this.cachedDatasets.values()).map((dataset) => dataset.toJSON()),
+        };
+        return JSON.stringify(obj);
+    }
+    /**
      * Fetch all [[DataSet]]s from the endpoint.
      */
     async datasets() {
-        if (this.datasetsLoaded) {
-            return this.cachedDatasets;
+        if (this.allDatasetsLoaded) {
+            return Array.from(this.cachedDatasets.values());
         }
-        const query = `
-      PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
-      PREFIX qb: <http://purl.org/linked-data/cube#>
-      SELECT ?dataSetIri ?dataSetLabel ?graphIri WHERE {
-        GRAPH ?graphIri {
-          ?dataSetIri a qb:DataSet ;
-          rdfs:label ?dataSetLabel .
+        const sparql = this.generateQuery();
+        const queryResult = await this.fetcher.select(sparql);
+        this.cacheDatasets(queryResult);
+        this.allDatasetsLoaded = true;
+        return Array.from(this.cachedDatasets.values());
+    }
+    /**
+     * Fetch a [[DataSet]] by its IRI.
+     *
+     * @param iri IRI of the DataSet to return.
+     */
+    async datasetByIri(dataSetIri) {
+        const found = Array.from(this.cachedDatasets.values()).find((dataset) => dataset.iri === dataSetIri);
+        if (found) {
+            return found;
         }
-      }
-    `;
-        const datasets = await this.fetcher.select(query);
-        this.datasetsLoaded = true;
-        return this.cachedDatasets = datasets.map(({ dataSetIri, dataSetLabel, graphIri }) => new DataSet(this.endpoint, { dataSetIri, dataSetLabel, graphIri }));
+        const sparql = this.generateQuery({ dataSetIri: namedNode(dataSetIri) });
+        const queryResult = await this.fetcher.select(sparql);
+        if (!queryResult.length) {
+            throw new Error(`No dataset with iri <${dataSetIri}> on ${this.endpoint}`);
+        }
+        this.cacheDatasets(queryResult);
+        return this.datasetByIri(dataSetIri);
     }
     /**
+     * Fetch [[DataSet]]s by their graph IRI.
+     *
+     * @param graphIri IRI of the graph to look for in all DataSets.
+     */
+    async datasetsByGraphIri(iri) {
+        const datasets = Array.from(this.cachedDatasets.values())
+            .filter((ds) => ds.graphIri === iri);
+        if (datasets.length) {
+            return datasets;
+        }
+        const graphIri = namedNode(iri);
+        const sparql = this.generateQuery({ graphIri });
+        const queryResult = await this.fetcher.select(sparql);
+        if (!queryResult.length) {
+            // avoid infinite recursion
+            throw new Error(`Cannot find graph <${iri}> in ${this.endpoint}`);
+        }
+        this.cacheDatasets(queryResult.map((result) => {
+            result.graphIri = graphIri;
+            return result;
+        }));
+        return this.datasetsByGraphIri(iri);
+    }
+    /**
      * Fetch all graphs from the endpoint.
@@ -43,3 +114,10 @@ */
         }
-        const query = "SELECT DISTINCT ?graph WHERE { GRAPH ?graph {?s ?p ?o}}";
+        const query = `
+      PREFIX qb: <http://purl.org/linked-data/cube#>
+      SELECT DISTINCT ?graph WHERE {
+        GRAPH ?graph {
+          ?dataset a qb:DataSet .
+        }
+      }
+    `;
         const graphs = await this.fetcher.select(query);
@@ -49,3 +127,74 @@ this.graphsLoaded = true;
     }
+    cacheDatasets(datasets) {
+        const datasetsByIri = datasets.reduce((acc, { iri, label, graphIri }) => {
+            if (!acc[iri.value]) {
+                acc[iri.value] = {
+                    iri,
+                    labels: [],
+                    graphIri,
+                    languages: this.languages,
+                };
+            }
+            acc[iri.value].labels.push({
+                value: label.value,
+                language: label.language,
+            });
+            return acc;
+        }, {});
+        Object.entries(datasetsByIri)
+            .forEach(([iri, dataset]) => {
+            this.cachedDatasets.set(iri, new DataSet(this.endpoint, dataset));
+        });
+    }
+    generateQuery({ graphIri, dataSetIri } = {}) {
+        const graphIriBinding = variable("graphIri");
+        const iriBinding = variable("iri");
+        const labelBinding = variable("label");
+        const query = {
+            prefixes,
+            queryType: "SELECT",
+            variables: [
+                iriBinding,
+                graphIriBinding,
+                labelBinding,
+            ],
+            where: [
+                {
+                    type: "graph",
+                    name: graphIri || graphIriBinding,
+                    patterns: [
+                        {
+                            type: "bgp",
+                            triples: [
+                                {
+                                    subject: iriBinding,
+                                    predicate: namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
+                                    object: namedNode("http://purl.org/linked-data/cube#DataSet"),
+                                },
+                            ],
+                        },
+                        ...generateLangOptionals(iriBinding, labelBinding, this.languages),
+                    ],
+                },
+                generateLangCoalesce(labelBinding, this.languages),
+            ],
+            type: "query",
+        };
+        if (dataSetIri) {
+            query.where.push({
+                type: "filter",
+                expression: {
+                    type: "operation",
+                    operator: "=",
+                    args: [
+                        iriBinding,
+                        dataSetIri,
+                    ],
+                },
+            });
+        }
+        const generator = new SparqlGenerator({ allPrefixes: true });
+        return generator.stringify(query);
+    }
 }
 //# sourceMappingURL=datacube.js.map

dist/es/dataset.d.ts

@@ -1,27 +0,44 @@
-import { NamedNode, Term } from "rdf-js";
-import Attribute from "./components/attribute";
-import Dimension from "./components/dimension";
-import Measure from "./components/measure";
-import DataSetQuery from "./datasetquery";
+import { NamedNode } from "rdf-js";
+import { Attribute, Dimension, Measure } from "./components";
+import { ICubeOptions } from "./datacube";
+import DataSetQuery from "./query/datasetquery";
+import { IQueryOptions } from "./query/utils";
+export declare type Label = {
+    value: string;
+    language?: string;
+};
+export interface IDataSetOptions extends ICubeOptions {
+    iri: NamedNode;
+    labels?: Label[];
+    graphIri: NamedNode;
+}
 declare class DataSet {
-    label: any;
+    /**
+     * Deserializes a DataSet from JSON generated by DataSet#toJSON
+     */
+    static fromJSON(json: string): DataSet;
+    labels: Label[];
     iri: string;
     endpoint: string;
-    graphIri: NamedNode | undefined;
+    graphIri?: string;
+    private languages;
     private fetcher;
-    private metadataLoaded;
-    private cachedMetadata;
+    private componentsLoaded;
+    private cachedComponents;
     /**
      * @param endpoint SPARQL endpoint where the DataSet lives.
      * @param options Additional info about the DataSet.
-     * @param options.dataSetIri The IRI of the DataSet.
-     * @param options.dataSetLabel (Optional) A label for the DataSet.
+     * @param options.iri The IRI of the DataSet.
      * @param options.graphIri The IRI of the graph from which the data will be fetched.
+     * @param options.labels (Optional) A list of labels for the DataSet in the following form:
+     * `[ { value: "Something", language: "en" }, { value: "Etwas", language: "de" }, … ]`
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
      */
-    constructor(endpoint: string, options: {
-        dataSetIri: NamedNode;
-        dataSetLabel?: Term;
-        graphIri: NamedNode;
-    });
+    constructor(endpoint: string, options: IDataSetOptions);
     /**
+     * Serializes a DataSet to JSON in a way that makes it deserializable
+     * by calling DataSet#fromJSON
+     */
+    toJSON(): string;
+    /**
      * Fetch all [[Attribute]]s from the DataSet.
@@ -41,5 +58,5 @@ */
      */
-    query(): DataSetQuery;
-    private metadata;
+    query(opts?: IQueryOptions): DataSetQuery;
+    private components;
 }
 export default DataSet;

dist/es/dataset.js

@@ -1,5 +0,6 @@
-import Attribute from "./components/attribute";
-import Dimension from "./components/dimension";
-import Measure from "./components/measure";
-import DataSetQuery from "./datasetquery";
+import { namedNode, variable } from "@rdfjs/data-model";
+import { Generator as SparqlGenerator } from "sparqljs";
+import Component, { Attribute, Dimension, Measure } from "./components";
+import DataSetQuery from "./query/datasetquery";
+import { generateLangCoalesce, generateLangOptionals, prefixes } from "./query/utils";
 import SparqlFetcher from "./sparqlfetcher";
@@ -10,21 +11,75 @@ class DataSet {
      * @param options Additional info about the DataSet.
-     * @param options.dataSetIri The IRI of the DataSet.
-     * @param options.dataSetLabel (Optional) A label for the DataSet.
+     * @param options.iri The IRI of the DataSet.
      * @param options.graphIri The IRI of the graph from which the data will be fetched.
+     * @param options.labels (Optional) A list of labels for the DataSet in the following form:
+     * `[ { value: "Something", language: "en" }, { value: "Etwas", language: "de" }, … ]`
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
      */
     constructor(endpoint, options) {
-        this.metadataLoaded = false;
-        const { dataSetIri, dataSetLabel, graphIri } = options;
+        this.componentsLoaded = false;
+        const { iri, labels, graphIri } = options;
         this.fetcher = new SparqlFetcher(endpoint);
-        this.iri = dataSetIri.value;
-        this.label = (dataSetLabel && dataSetLabel.value) || "";
-        this.graphIri = graphIri;
         this.endpoint = endpoint;
+        this.iri = iri.value;
+        this.graphIri = graphIri.value;
+        this.labels = labels || [];
+        this.languages = options.languages || ["de", "it"];
+        this.cachedComponents = {
+            dimensions: new Map(),
+            measures: new Map(),
+            attributes: new Map(),
+        };
     }
     /**
+     * Deserializes a DataSet from JSON generated by DataSet#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        const dataset = new DataSet(obj.endpoint, {
+            iri: namedNode(obj.iri),
+            graphIri: namedNode(obj.graphIri),
+            labels: obj.labels,
+            languages: obj.languages,
+        });
+        ["dimensions", "measures", "attributes"].forEach((componentTypes) => {
+            dataset.cachedComponents[componentTypes] = obj.components[componentTypes]
+                .map(Component.fromJSON)
+                .reduce((cache, component) => {
+                cache.set(component.iri.value, component);
+                return cache;
+            }, new Map());
+        });
+        return dataset;
+    }
+    /**
+     * Serializes a DataSet to JSON in a way that makes it deserializable
+     * by calling DataSet#fromJSON
+     */
+    toJSON() {
+        const dimensions = Array.from(this.cachedComponents.dimensions.values())
+            .map((component) => component.toJSON());
+        const measures = Array.from(this.cachedComponents.measures.values())
+            .map((component) => component.toJSON());
+        const attributes = Array.from(this.cachedComponents.attributes.values())
+            .map((component) => component.toJSON());
+        const obj = {
+            endpoint: this.endpoint,
+            iri: this.iri,
+            graphIri: this.graphIri,
+            labels: this.labels,
+            languages: this.languages,
+            components: {
+                dimensions,
+                measures,
+                attributes,
+            },
+        };
+        return JSON.stringify(obj);
+    }
+    /**
      * Fetch all [[Attribute]]s from the DataSet.
      */
     async attributes() {
-        await this.metadata();
-        return this.cachedMetadata.attributes;
+        await this.components();
+        return Array.from(this.cachedComponents.attributes.values());
     }
@@ -35,4 +90,4 @@ /**
     async dimensions() {
-        await this.metadata();
-        return this.cachedMetadata.dimensions;
+        await this.components();
+        return Array.from(this.cachedComponents.dimensions.values());
     }
@@ -43,4 +98,4 @@ /**
     async measures() {
-        await this.metadata();
-        return this.cachedMetadata.measures;
+        await this.components();
+        return Array.from(this.cachedComponents.measures.values());
     }
@@ -50,35 +105,100 @@ /**
      */
-    query() {
-        return new DataSetQuery(this);
+    query(opts = {}) {
+        if (!opts.languages) {
+            opts.languages = this.languages;
+        }
+        return new DataSetQuery(this, opts);
     }
-    async metadata() {
-        if (this.metadataLoaded) {
+    async components() {
+        if (this.componentsLoaded) {
             return;
         }
-        const query = `
-      PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
-      PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
-      PREFIX qb: <http://purl.org/linked-data/cube#>
-      PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
-
-      SELECT ?label ?kind ?iri
-
-      ${this.graphIri ? `FROM <${this.graphIri.value}>` : ""}
-      WHERE {
-        <${this.iri}> a qb:DataSet ;
-          qb:structure/qb:component ?componentSpec .
-        ?componentSpec ?kind ?iri .
-        ?iri rdfs:label|skos:prefLabel ?label .
-      }`;
-        const metadata = await this.fetcher.select(query);
-        this.cachedMetadata = metadata.reduce((metadataProp, { kind, label, iri }) => {
+        const binding = variable("iri");
+        const labelBinding = variable("label");
+        const query = {
+            prefixes,
+            queryType: "SELECT",
+            variables: [
+                binding,
+                variable("kind"),
+                labelBinding,
+            ],
+            from: { default: [namedNode(this.graphIri)], named: [] },
+            where: [
+                {
+                    type: "bgp",
+                    triples: [
+                        {
+                            subject: namedNode(this.iri),
+                            predicate: namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
+                            object: namedNode("http://purl.org/linked-data/cube#DataSet"),
+                        },
+                        {
+                            subject: namedNode(this.iri),
+                            predicate: {
+                                type: "path",
+                                pathType: "/",
+                                items: [
+                                    namedNode("http://purl.org/linked-data/cube#structure"),
+                                    namedNode("http://purl.org/linked-data/cube#component"),
+                                ],
+                            },
+                            object: variable("componentSpec"),
+                        },
+                        {
+                            subject: variable("componentSpec"),
+                            predicate: variable("kind"),
+                            object: binding,
+                        },
+                    ],
+                },
+                {
+                    type: "filter",
+                    expression: {
+                        type: "operation",
+                        operator: "in",
+                        args: [
+                            variable("kind"),
+                            [
+                                namedNode("http://purl.org/linked-data/cube#attribute"),
+                                namedNode("http://purl.org/linked-data/cube#dimension"),
+                                namedNode("http://purl.org/linked-data/cube#measure"),
+                            ],
+                        ],
+                    },
+                },
+                ...generateLangOptionals(binding, labelBinding, this.languages),
+                generateLangCoalesce(labelBinding, this.languages),
+            ],
+            type: "query",
+        };
+        const generator = new SparqlGenerator({ allPrefixes: true });
+        const sparql = generator.stringify(query);
+        const components = await this.fetcher.select(sparql);
+        const componentsByIri = components.reduce((acc, { kind, label, iri }) => {
+            if (!acc[iri.value]) {
+                acc[iri.value] = {
+                    kind,
+                    labels: [],
+                    iri,
+                };
+            }
+            acc[iri.value].labels.push({
+                value: label.value,
+                language: label.language,
+            });
+            return acc;
+        }, {});
+        const groupedComponents = Object.values(componentsByIri);
+        this.cachedComponents = groupedComponents
+            .reduce((componentsProp, { kind, labels, iri }) => {
             switch (kind.value) {
                 case "http://purl.org/linked-data/cube#attribute":
-                    metadataProp.attributes.push(new Attribute({ label, iri }));
+                    componentsProp.attributes.set(iri.value, new Attribute({ labels, iri }));
                     break;
                 case "http://purl.org/linked-data/cube#dimension":
-                    metadataProp.dimensions.push(new Dimension({ label, iri }));
+                    componentsProp.dimensions.set(iri.value, new Dimension({ labels, iri }));
                     break;
                 case "http://purl.org/linked-data/cube#measure":
-                    metadataProp.measures.push(new Measure({ label, iri }));
+                    componentsProp.measures.set(iri.value, new Measure({ labels, iri }));
                     break;
@@ -88,9 +208,9 @@ default:
             }
-            return metadataProp;
+            return componentsProp;
         }, {
-            attributes: [],
-            dimensions: [],
-            measures: [],
+            attributes: new Map(),
+            dimensions: new Map(),
+            measures: new Map(),
         });
-        this.metadataLoaded = true;
+        this.componentsLoaded = true;
     }
@@ -97,0 +217,0 @@ }

dist/es/expressions/utils.d.ts

@@ -1,2 +0,2 @@
-import { Term } from "rdf-js";
+import { Literal, Term } from "rdf-js";
 export interface IExpr {
@@ -18,1 +18,2 @@ resolve(mapping: Map<string, string>): IExpr;
 export declare function into(what: IntoExpr): IExpr;
+export declare function toLiteral(arg: any): Literal;

dist/es/expressions/utils.js

 // tslint:disable: max-classes-per-file
 import { blankNode, defaultGraph, literal, namedNode, variable } from "@rdfjs/data-model";
-import { toLiteral } from "../toLiteral";
+import namespace from "@rdfjs/namespace";
 import Binding from "./binding";
 import Operator from "./operator";
+const xsd = namespace("http://www.w3.org/2001/XMLSchema#");
+const dateTime = /^\d{4}(-[01]\d(-[0-3]\d(T[0-2]\d:[0-5]\d:?([0-5]\d(\.\d+)?)?([+-][0-2]\d:[0-5]\d)?Z?)?)?)$/;
+const bool = /^(true|false)$/;
+const numb = /^[\-+]?(?:\d+\.?\d*([eE](?:[\-\+])?\d+)|\d*\.?\d+)$/;
 export class TermExpr {
@@ -60,2 +64,41 @@ constructor(term) {
 }
+export function toLiteral(arg) {
+    if (isLiteral(arg)) {
+        return arg;
+    }
+    if (arg === true || arg === false) {
+        return literal(String(arg), xsd("boolean"));
+    }
+    if (bool.test(arg)) {
+        return literal(arg, xsd("boolean"));
+    }
+    if (arg instanceof Date) {
+        return literal(arg.toISOString(), xsd("dateTime"));
+    }
+    if (dateTime.test(arg)) {
+        const date = new Date(arg);
+        return literal(date.toISOString(), xsd("dateTime"));
+    }
+    if (/^[0-9+-]/.test(arg)) {
+        const match = numb.exec(arg);
+        if (match) {
+            const value = match[0];
+            let type;
+            if (match[1]) {
+                type = xsd("double");
+            }
+            else if (/^[+\-]?\d+$/.test(match[0])) {
+                type = xsd("integer");
+            }
+            else {
+                type = xsd("decimal");
+            }
+            return literal(String(value), type);
+        }
+    }
+    return literal(arg);
+}
+function isLiteral(term) {
+    return (term instanceof literal("").constructor);
+}
 //# sourceMappingURL=utils.js.map

dist/node/components/component.d.ts

 import { Term } from "rdf-js";
+import { Label } from "../dataset";
 import BaseExpr from "../expressions/base";
 import { IExpr } from "../expressions/utils";
 declare class Component extends BaseExpr {
-    label: Term;
+    /**
+     * Deserializes a Component from JSON generated by Component#toJSON
+     */
+    static fromJSON(json: string): Component;
+    labels: Label[];
     iri: Term;
@@ -11,6 +16,11 @@ aggregateType: string;
     componentType: string;
-    constructor({ label, iri }: {
-        label: string | Term;
+    constructor({ labels, iri }: {
+        labels: Label[];
         iri: string | Term;
     });
+    /**
+     * Serializes a Component to JSON in a way that makes it deserializable
+     * by calling Component#fromJSON
+     */
+    toJSON(): string;
     clone(): any;
@@ -17,0 +27,0 @@ avg(): any;

dist/node/components/component.js

@@ -7,6 +7,7 @@ "use strict";
 const data_model_1 = require("@rdfjs/data-model");
+const clone_1 = __importDefault(require("clone"));
 const base_1 = __importDefault(require("../expressions/base"));
 const binding_1 = __importDefault(require("../expressions/binding"));
 class Component extends base_1.default {
-    constructor({ label, iri }) {
+    constructor({ labels, iri }) {
         super();
@@ -16,8 +17,3 @@ this.isDistinct = false;
         this.componentType = "";
-        if (typeof label === "string") {
-            this.label = data_model_1.literal(label);
-        }
-        else {
-            this.label = label;
-        }
+        this.labels = labels || [];
         if (typeof iri === "string") {
@@ -30,5 +26,33 @@ this.iri = data_model_1.namedNode(iri);
     }
+    /**
+     * Deserializes a Component from JSON generated by Component#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        obj.iri = data_model_1.namedNode(obj.iri);
+        switch (obj.componentType) {
+            case "measure":
+                return new measure_1.default(obj);
+            case "dimension":
+                return new dimension_1.default(obj);
+            case "attribute":
+                return new attribute_1.default(obj);
+        }
+        throw new Error(`Unknown component type '${obj.componentType}'`);
+    }
+    /**
+     * Serializes a Component to JSON in a way that makes it deserializable
+     * by calling Component#fromJSON
+     */
+    toJSON() {
+        const obj = {
+            componentType: this.componentType,
+            iri: this.iri.value,
+            labels: this.labels,
+        };
+        return JSON.stringify(obj);
+    }
     clone() {
         const Constructor = Object.getPrototypeOf(this).constructor;
-        const state = { label: this.label, iri: this.iri };
+        const state = { labels: clone_1.default(this.labels), iri: this.iri };
         const instance = new Constructor(state);
@@ -59,2 +83,5 @@ instance.aggregateType = this.aggregateType;
 exports.default = Component;
+const attribute_1 = __importDefault(require("./attribute"));
+const dimension_1 = __importDefault(require("./dimension"));
+const measure_1 = __importDefault(require("./measure"));
 //# sourceMappingURL=component.js.map

dist/node/datacube.d.ts

 import { NamedNode } from "rdf-js";
 import DataSet from "./dataset";
+export interface ICubeOptions {
+    languages?: string[];
+}
 export declare class DataCube {
+    /**
+     * Deserializes a DataCube from JSON generated by DataCube#toJSON
+     */
+    static fromJSON(json: string): DataCube;
     private endpoint;
+    private languages;
     private fetcher;
     private cachedDatasets;
-    private datasetsLoaded;
+    private allDatasetsLoaded;
     private cachedGraphs;
     private graphsLoaded;
     /**
+     * A DataCube queries a SPARQL endpoint and retrieves [[DataSet]]s and
+     * their [[Dimension]]s, [[Measure]]s and [[Attribute]]s.
+     * @class DataCube
      * @param endpoint SPARQL endpoint
+     * @param options Options
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
+     * Passed down to [[DataSet]]s and [[DataSetQuery]].
      */
-    constructor(endpoint: string);
+    constructor(endpoint: string, options?: ICubeOptions);
     /**
+     * Serializes a DataCube to JSON in a way that makes it deserializable
+     * by calling DataCube#fromJSON
+     */
+    toJSON(): string;
+    /**
      * Fetch all [[DataSet]]s from the endpoint.
@@ -19,5 +38,19 @@ */
     /**
+     * Fetch a [[DataSet]] by its IRI.
+     *
+     * @param iri IRI of the DataSet to return.
+     */
+    datasetByIri(dataSetIri: string): Promise<DataSet>;
+    /**
+     * Fetch [[DataSet]]s by their graph IRI.
+     *
+     * @param graphIri IRI of the graph to look for in all DataSets.
+     */
+    datasetsByGraphIri(iri: string): Promise<DataSet[]>;
+    /**
      * Fetch all graphs from the endpoint.
      */
     graphs(): Promise<NamedNode[]>;
+    private cacheDatasets;
+    private generateQuery;
 }

dist/node/datacube.js

@@ -6,38 +6,109 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
+const data_model_1 = require("@rdfjs/data-model");
+const sparqljs_1 = require("sparqljs");
 const dataset_1 = __importDefault(require("./dataset"));
+const utils_1 = require("./query/utils");
 const sparqlfetcher_1 = __importDefault(require("./sparqlfetcher"));
 class DataCube {
     /**
+     * A DataCube queries a SPARQL endpoint and retrieves [[DataSet]]s and
+     * their [[Dimension]]s, [[Measure]]s and [[Attribute]]s.
+     * @class DataCube
      * @param endpoint SPARQL endpoint
+     * @param options Options
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
+     * Passed down to [[DataSet]]s and [[DataSetQuery]].
      */
-    constructor(endpoint) {
-        this.datasetsLoaded = false;
+    constructor(endpoint, options = {}) {
+        this.allDatasetsLoaded = false;
         this.graphsLoaded = false;
         this.endpoint = endpoint;
+        this.languages = options.languages || ["de", "it"];
         this.fetcher = new sparqlfetcher_1.default(endpoint);
-        this.cachedDatasets = [];
+        this.cachedDatasets = new Map();
         this.cachedGraphs = [];
     }
     /**
+     * Deserializes a DataCube from JSON generated by DataCube#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        const datacube = new DataCube(obj.endpoint, {
+            languages: obj.languages,
+        });
+        datacube.cachedDatasets = obj.datasets.reduce((map, str) => {
+            const dataset = dataset_1.default.fromJSON(str);
+            map.set(dataset.iri, dataset);
+            return map;
+        }, new Map());
+        return datacube;
+    }
+    /**
+     * Serializes a DataCube to JSON in a way that makes it deserializable
+     * by calling DataCube#fromJSON
+     */
+    toJSON() {
+        const obj = {
+            endpoint: this.endpoint,
+            languages: this.languages,
+            datasets: Array.from(this.cachedDatasets.values()).map((dataset) => dataset.toJSON()),
+        };
+        return JSON.stringify(obj);
+    }
+    /**
      * Fetch all [[DataSet]]s from the endpoint.
      */
     async datasets() {
-        if (this.datasetsLoaded) {
-            return this.cachedDatasets;
+        if (this.allDatasetsLoaded) {
+            return Array.from(this.cachedDatasets.values());
         }
-        const query = `
-      PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
-      PREFIX qb: <http://purl.org/linked-data/cube#>
-      SELECT ?dataSetIri ?dataSetLabel ?graphIri WHERE {
-        GRAPH ?graphIri {
-          ?dataSetIri a qb:DataSet ;
-          rdfs:label ?dataSetLabel .
+        const sparql = this.generateQuery();
+        const queryResult = await this.fetcher.select(sparql);
+        this.cacheDatasets(queryResult);
+        this.allDatasetsLoaded = true;
+        return Array.from(this.cachedDatasets.values());
+    }
+    /**
+     * Fetch a [[DataSet]] by its IRI.
+     *
+     * @param iri IRI of the DataSet to return.
+     */
+    async datasetByIri(dataSetIri) {
+        const found = Array.from(this.cachedDatasets.values()).find((dataset) => dataset.iri === dataSetIri);
+        if (found) {
+            return found;
         }
-      }
-    `;
-        const datasets = await this.fetcher.select(query);
-        this.datasetsLoaded = true;
-        return this.cachedDatasets = datasets.map(({ dataSetIri, dataSetLabel, graphIri }) => new dataset_1.default(this.endpoint, { dataSetIri, dataSetLabel, graphIri }));
+        const sparql = this.generateQuery({ dataSetIri: data_model_1.namedNode(dataSetIri) });
+        const queryResult = await this.fetcher.select(sparql);
+        if (!queryResult.length) {
+            throw new Error(`No dataset with iri <${dataSetIri}> on ${this.endpoint}`);
+        }
+        this.cacheDatasets(queryResult);
+        return this.datasetByIri(dataSetIri);
     }
     /**
+     * Fetch [[DataSet]]s by their graph IRI.
+     *
+     * @param graphIri IRI of the graph to look for in all DataSets.
+     */
+    async datasetsByGraphIri(iri) {
+        const datasets = Array.from(this.cachedDatasets.values())
+            .filter((ds) => ds.graphIri === iri);
+        if (datasets.length) {
+            return datasets;
+        }
+        const graphIri = data_model_1.namedNode(iri);
+        const sparql = this.generateQuery({ graphIri });
+        const queryResult = await this.fetcher.select(sparql);
+        if (!queryResult.length) {
+            // avoid infinite recursion
+            throw new Error(`Cannot find graph <${iri}> in ${this.endpoint}`);
+        }
+        this.cacheDatasets(queryResult.map((result) => {
+            result.graphIri = graphIri;
+            return result;
+        }));
+        return this.datasetsByGraphIri(iri);
+    }
+    /**
      * Fetch all graphs from the endpoint.
@@ -49,3 +120,10 @@ */
         }
-        const query = "SELECT DISTINCT ?graph WHERE { GRAPH ?graph {?s ?p ?o}}";
+        const query = `
+      PREFIX qb: <http://purl.org/linked-data/cube#>
+      SELECT DISTINCT ?graph WHERE {
+        GRAPH ?graph {
+          ?dataset a qb:DataSet .
+        }
+      }
+    `;
         const graphs = await this.fetcher.select(query);
@@ -55,4 +133,75 @@ this.graphsLoaded = true;
     }
+    cacheDatasets(datasets) {
+        const datasetsByIri = datasets.reduce((acc, { iri, label, graphIri }) => {
+            if (!acc[iri.value]) {
+                acc[iri.value] = {
+                    iri,
+                    labels: [],
+                    graphIri,
+                    languages: this.languages,
+                };
+            }
+            acc[iri.value].labels.push({
+                value: label.value,
+                language: label.language,
+            });
+            return acc;
+        }, {});
+        Object.entries(datasetsByIri)
+            .forEach(([iri, dataset]) => {
+            this.cachedDatasets.set(iri, new dataset_1.default(this.endpoint, dataset));
+        });
+    }
+    generateQuery({ graphIri, dataSetIri } = {}) {
+        const graphIriBinding = data_model_1.variable("graphIri");
+        const iriBinding = data_model_1.variable("iri");
+        const labelBinding = data_model_1.variable("label");
+        const query = {
+            prefixes: utils_1.prefixes,
+            queryType: "SELECT",
+            variables: [
+                iriBinding,
+                graphIriBinding,
+                labelBinding,
+            ],
+            where: [
+                {
+                    type: "graph",
+                    name: graphIri || graphIriBinding,
+                    patterns: [
+                        {
+                            type: "bgp",
+                            triples: [
+                                {
+                                    subject: iriBinding,
+                                    predicate: data_model_1.namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
+                                    object: data_model_1.namedNode("http://purl.org/linked-data/cube#DataSet"),
+                                },
+                            ],
+                        },
+                        ...utils_1.generateLangOptionals(iriBinding, labelBinding, this.languages),
+                    ],
+                },
+                utils_1.generateLangCoalesce(labelBinding, this.languages),
+            ],
+            type: "query",
+        };
+        if (dataSetIri) {
+            query.where.push({
+                type: "filter",
+                expression: {
+                    type: "operation",
+                    operator: "=",
+                    args: [
+                        iriBinding,
+                        dataSetIri,
+                    ],
+                },
+            });
+        }
+        const generator = new sparqljs_1.Generator({ allPrefixes: true });
+        return generator.stringify(query);
+    }
 }
 exports.DataCube = DataCube;
 //# sourceMappingURL=datacube.js.map

dist/node/dataset.d.ts

@@ -1,27 +0,44 @@
-import { NamedNode, Term } from "rdf-js";
-import Attribute from "./components/attribute";
-import Dimension from "./components/dimension";
-import Measure from "./components/measure";
-import DataSetQuery from "./datasetquery";
+import { NamedNode } from "rdf-js";
+import { Attribute, Dimension, Measure } from "./components";
+import { ICubeOptions } from "./datacube";
+import DataSetQuery from "./query/datasetquery";
+import { IQueryOptions } from "./query/utils";
+export declare type Label = {
+    value: string;
+    language?: string;
+};
+export interface IDataSetOptions extends ICubeOptions {
+    iri: NamedNode;
+    labels?: Label[];
+    graphIri: NamedNode;
+}
 declare class DataSet {
-    label: any;
+    /**
+     * Deserializes a DataSet from JSON generated by DataSet#toJSON
+     */
+    static fromJSON(json: string): DataSet;
+    labels: Label[];
     iri: string;
     endpoint: string;
-    graphIri: NamedNode | undefined;
+    graphIri?: string;
+    private languages;
     private fetcher;
-    private metadataLoaded;
-    private cachedMetadata;
+    private componentsLoaded;
+    private cachedComponents;
     /**
      * @param endpoint SPARQL endpoint where the DataSet lives.
      * @param options Additional info about the DataSet.
-     * @param options.dataSetIri The IRI of the DataSet.
-     * @param options.dataSetLabel (Optional) A label for the DataSet.
+     * @param options.iri The IRI of the DataSet.
      * @param options.graphIri The IRI of the graph from which the data will be fetched.
+     * @param options.labels (Optional) A list of labels for the DataSet in the following form:
+     * `[ { value: "Something", language: "en" }, { value: "Etwas", language: "de" }, … ]`
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
      */
-    constructor(endpoint: string, options: {
-        dataSetIri: NamedNode;
-        dataSetLabel?: Term;
-        graphIri: NamedNode;
-    });
+    constructor(endpoint: string, options: IDataSetOptions);
     /**
+     * Serializes a DataSet to JSON in a way that makes it deserializable
+     * by calling DataSet#fromJSON
+     */
+    toJSON(): string;
+    /**
      * Fetch all [[Attribute]]s from the DataSet.
@@ -41,5 +58,5 @@ */
      */
-    query(): DataSetQuery;
-    private metadata;
+    query(opts?: IQueryOptions): DataSetQuery;
+    private components;
 }
 export default DataSet;

dist/node/dataset.js

 "use strict";
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
+    result["default"] = mod;
+    return result;
+};
 var __importDefault = (this && this.__importDefault) || function (mod) {
@@ -6,6 +13,7 @@ return (mod && mod.__esModule) ? mod : { "default": mod };
 Object.defineProperty(exports, "__esModule", { value: true });
-const attribute_1 = __importDefault(require("./components/attribute"));
-const dimension_1 = __importDefault(require("./components/dimension"));
-const measure_1 = __importDefault(require("./components/measure"));
-const datasetquery_1 = __importDefault(require("./datasetquery"));
+const data_model_1 = require("@rdfjs/data-model");
+const sparqljs_1 = require("sparqljs");
+const components_1 = __importStar(require("./components"));
+const datasetquery_1 = __importDefault(require("./query/datasetquery"));
+const utils_1 = require("./query/utils");
 const sparqlfetcher_1 = __importDefault(require("./sparqlfetcher"));
@@ -16,21 +24,75 @@ class DataSet {
      * @param options Additional info about the DataSet.
-     * @param options.dataSetIri The IRI of the DataSet.
-     * @param options.dataSetLabel (Optional) A label for the DataSet.
+     * @param options.iri The IRI of the DataSet.
      * @param options.graphIri The IRI of the graph from which the data will be fetched.
+     * @param options.labels (Optional) A list of labels for the DataSet in the following form:
+     * `[ { value: "Something", language: "en" }, { value: "Etwas", language: "de" }, … ]`
+     * @param options.languages Languages in which to get the labels, by priority, e.g. `["de", "en"]`.
      */
     constructor(endpoint, options) {
-        this.metadataLoaded = false;
-        const { dataSetIri, dataSetLabel, graphIri } = options;
+        this.componentsLoaded = false;
+        const { iri, labels, graphIri } = options;
         this.fetcher = new sparqlfetcher_1.default(endpoint);
-        this.iri = dataSetIri.value;
-        this.label = (dataSetLabel && dataSetLabel.value) || "";
-        this.graphIri = graphIri;
         this.endpoint = endpoint;
+        this.iri = iri.value;
+        this.graphIri = graphIri.value;
+        this.labels = labels || [];
+        this.languages = options.languages || ["de", "it"];
+        this.cachedComponents = {
+            dimensions: new Map(),
+            measures: new Map(),
+            attributes: new Map(),
+        };
     }
     /**
+     * Deserializes a DataSet from JSON generated by DataSet#toJSON
+     */
+    static fromJSON(json) {
+        const obj = JSON.parse(json);
+        const dataset = new DataSet(obj.endpoint, {
+            iri: data_model_1.namedNode(obj.iri),
+            graphIri: data_model_1.namedNode(obj.graphIri),
+            labels: obj.labels,
+            languages: obj.languages,
+        });
+        ["dimensions", "measures", "attributes"].forEach((componentTypes) => {
+            dataset.cachedComponents[componentTypes] = obj.components[componentTypes]
+                .map(components_1.default.fromJSON)
+                .reduce((cache, component) => {
+                cache.set(component.iri.value, component);
+                return cache;
+            }, new Map());
+        });
+        return dataset;
+    }
+    /**
+     * Serializes a DataSet to JSON in a way that makes it deserializable
+     * by calling DataSet#fromJSON
+     */
+    toJSON() {
+        const dimensions = Array.from(this.cachedComponents.dimensions.values())
+            .map((component) => component.toJSON());
+        const measures = Array.from(this.cachedComponents.measures.values())
+            .map((component) => component.toJSON());
+        const attributes = Array.from(this.cachedComponents.attributes.values())
+            .map((component) => component.toJSON());
+        const obj = {
+            endpoint: this.endpoint,
+            iri: this.iri,
+            graphIri: this.graphIri,
+            labels: this.labels,
+            languages: this.languages,
+            components: {
+                dimensions,
+                measures,
+                attributes,
+            },
+        };
+        return JSON.stringify(obj);
+    }
+    /**
      * Fetch all [[Attribute]]s from the DataSet.
      */
     async attributes() {
-        await this.metadata();
-        return this.cachedMetadata.attributes;
+        await this.components();
+        return Array.from(this.cachedComponents.attributes.values());
     }
@@ -41,4 +103,4 @@ /**
     async dimensions() {
-        await this.metadata();
-        return this.cachedMetadata.dimensions;
+        await this.components();
+        return Array.from(this.cachedComponents.dimensions.values());
     }
@@ -49,4 +111,4 @@ /**
     async measures() {
-        await this.metadata();
-        return this.cachedMetadata.measures;
+        await this.components();
+        return Array.from(this.cachedComponents.measures.values());
     }
@@ -56,35 +118,100 @@ /**
      */
-    query() {
-        return new datasetquery_1.default(this);
+    query(opts = {}) {
+        if (!opts.languages) {
+            opts.languages = this.languages;
+        }
+        return new datasetquery_1.default(this, opts);
     }
-    async metadata() {
-        if (this.metadataLoaded) {
+    async components() {
+        if (this.componentsLoaded) {
             return;
         }
-        const query = `
-      PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
-      PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
-      PREFIX qb: <http://purl.org/linked-data/cube#>
-      PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
-
-      SELECT ?label ?kind ?iri
-
-      ${this.graphIri ? `FROM <${this.graphIri.value}>` : ""}
-      WHERE {
-        <${this.iri}> a qb:DataSet ;
-          qb:structure/qb:component ?componentSpec .
-        ?componentSpec ?kind ?iri .
-        ?iri rdfs:label|skos:prefLabel ?label .
-      }`;
-        const metadata = await this.fetcher.select(query);
-        this.cachedMetadata = metadata.reduce((metadataProp, { kind, label, iri }) => {
+        const binding = data_model_1.variable("iri");
+        const labelBinding = data_model_1.variable("label");
+        const query = {
+            prefixes: utils_1.prefixes,
+            queryType: "SELECT",
+            variables: [
+                binding,
+                data_model_1.variable("kind"),
+                labelBinding,
+            ],
+            from: { default: [data_model_1.namedNode(this.graphIri)], named: [] },
+            where: [
+                {
+                    type: "bgp",
+                    triples: [
+                        {
+                            subject: data_model_1.namedNode(this.iri),
+                            predicate: data_model_1.namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
+                            object: data_model_1.namedNode("http://purl.org/linked-data/cube#DataSet"),
+                        },
+                        {
+                            subject: data_model_1.namedNode(this.iri),
+                            predicate: {
+                                type: "path",
+                                pathType: "/",
+                                items: [
+                                    data_model_1.namedNode("http://purl.org/linked-data/cube#structure"),
+                                    data_model_1.namedNode("http://purl.org/linked-data/cube#component"),
+                                ],
+                            },
+                            object: data_model_1.variable("componentSpec"),
+                        },
+                        {
+                            subject: data_model_1.variable("componentSpec"),
+                            predicate: data_model_1.variable("kind"),
+                            object: binding,
+                        },
+                    ],
+                },
+                {
+                    type: "filter",
+                    expression: {
+                        type: "operation",
+                        operator: "in",
+                        args: [
+                            data_model_1.variable("kind"),
+                            [
+                                data_model_1.namedNode("http://purl.org/linked-data/cube#attribute"),
+                                data_model_1.namedNode("http://purl.org/linked-data/cube#dimension"),
+                                data_model_1.namedNode("http://purl.org/linked-data/cube#measure"),
+                            ],
+                        ],
+                    },
+                },
+                ...utils_1.generateLangOptionals(binding, labelBinding, this.languages),
+                utils_1.generateLangCoalesce(labelBinding, this.languages),
+            ],
+            type: "query",
+        };
+        const generator = new sparqljs_1.Generator({ allPrefixes: true });
+        const sparql = generator.stringify(query);
+        const components = await this.fetcher.select(sparql);
+        const componentsByIri = components.reduce((acc, { kind, label, iri }) => {
+            if (!acc[iri.value]) {
+                acc[iri.value] = {
+                    kind,
+                    labels: [],
+                    iri,
+                };
+            }
+            acc[iri.value].labels.push({
+                value: label.value,
+                language: label.language,
+            });
+            return acc;
+        }, {});
+        const groupedComponents = Object.values(componentsByIri);
+        this.cachedComponents = groupedComponents
+            .reduce((componentsProp, { kind, labels, iri }) => {
             switch (kind.value) {
                 case "http://purl.org/linked-data/cube#attribute":
-                    metadataProp.attributes.push(new attribute_1.default({ label, iri }));
+                    componentsProp.attributes.set(iri.value, new components_1.Attribute({ labels, iri }));
                     break;
                 case "http://purl.org/linked-data/cube#dimension":
-                    metadataProp.dimensions.push(new dimension_1.default({ label, iri }));
+                    componentsProp.dimensions.set(iri.value, new components_1.Dimension({ labels, iri }));
                     break;
                 case "http://purl.org/linked-data/cube#measure":
-                    metadataProp.measures.push(new measure_1.default({ label, iri }));
+                    componentsProp.measures.set(iri.value, new components_1.Measure({ labels, iri }));
                     break;
@@ -94,9 +221,9 @@ default:
             }
-            return metadataProp;
+            return componentsProp;
         }, {
-            attributes: [],
-            dimensions: [],
-            measures: [],
+            attributes: new Map(),
+            dimensions: new Map(),
+            measures: new Map(),
         });
-        this.metadataLoaded = true;
+        this.componentsLoaded = true;
     }
@@ -103,0 +230,0 @@ }

dist/node/expressions/utils.d.ts

@@ -1,2 +0,2 @@
-import { Term } from "rdf-js";
+import { Literal, Term } from "rdf-js";
 export interface IExpr {
@@ -18,1 +18,2 @@ resolve(mapping: Map<string, string>): IExpr;
 export declare function into(what: IntoExpr): IExpr;
+export declare function toLiteral(arg: any): Literal;

dist/node/expressions/utils.js

@@ -8,5 +8,9 @@ "use strict";
 const data_model_1 = require("@rdfjs/data-model");
-const toLiteral_1 = require("../toLiteral");
+const namespace_1 = __importDefault(require("@rdfjs/namespace"));
 const binding_1 = __importDefault(require("./binding"));
 const operator_1 = __importDefault(require("./operator"));
+const xsd = namespace_1.default("http://www.w3.org/2001/XMLSchema#");
+const dateTime = /^\d{4}(-[01]\d(-[0-3]\d(T[0-2]\d:[0-5]\d:?([0-5]\d(\.\d+)?)?([+-][0-2]\d:[0-5]\d)?Z?)?)?)$/;
+const bool = /^(true|false)$/;
+const numb = /^[\-+]?(?:\d+\.?\d*([eE](?:[\-\+])?\d+)|\d*\.?\d+)$/;
 class TermExpr {
@@ -41,3 +45,3 @@ constructor(term) {
         case "number":
-            return new TermExpr(toLiteral_1.toLiteral(what));
+            return new TermExpr(toLiteral(what));
         case "string":
@@ -48,3 +52,3 @@ const iriRegExp = new RegExp("^https?://");
             }
-            return new TermExpr(toLiteral_1.toLiteral(what));
+            return new TermExpr(toLiteral(what));
         case "object":
@@ -72,2 +76,42 @@ if (what instanceof operator_1.default ||
 exports.into = into;
+function toLiteral(arg) {
+    if (isLiteral(arg)) {
+        return arg;
+    }
+    if (arg === true || arg === false) {
+        return data_model_1.literal(String(arg), xsd("boolean"));
+    }
+    if (bool.test(arg)) {
+        return data_model_1.literal(arg, xsd("boolean"));
+    }
+    if (arg instanceof Date) {
+        return data_model_1.literal(arg.toISOString(), xsd("dateTime"));
+    }
+    if (dateTime.test(arg)) {
+        const date = new Date(arg);
+        return data_model_1.literal(date.toISOString(), xsd("dateTime"));
+    }
+    if (/^[0-9+-]/.test(arg)) {
+        const match = numb.exec(arg);
+        if (match) {
+            const value = match[0];
+            let type;
+            if (match[1]) {
+                type = xsd("double");
+            }
+            else if (/^[+\-]?\d+$/.test(match[0])) {
+                type = xsd("integer");
+            }
+            else {
+                type = xsd("decimal");
+            }
+            return data_model_1.literal(String(value), type);
+        }
+    }
+    return data_model_1.literal(arg);
+}
+exports.toLiteral = toLiteral;
+function isLiteral(term) {
+    return (term instanceof data_model_1.literal("").constructor);
+}
 //# sourceMappingURL=utils.js.map

package.json

 {
   "name": "@zazuko/query-rdf-data-cube",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Query (or introspect) [RDF Data Cubes](https://www.w3.org/TR/vocab-data-cube/) with a JavaScript API, without writing SPARQL.",
@@ -15,6 +15,7 @@ "scripts": {
     "prepare": "npm run build",
-    "version": "conventional-changelog -p angular -i CHANGELOG.md -s && git add CHANGELOG.md"
+    "version": "conventional-changelog -p angular -i CHANGELOG.md -s && git add CHANGELOG.md",
+    "postversion": "npm run docs:compile && npm run docs:publish"
   },
-  "main": "dist/node/datacube.js",
-  "module": "dist/es/index.js",
+  "main": "dist/node/src/datacube.js",
+  "module": "dist/es/src/datacube.js",
   "files": [
@@ -21,0 +22,0 @@ "dist"

README.md

 # [@zazuko/query-rdf-data-cube](https://github.com/zazuko/query-rdf-data-cube)
 
-[![Build Status](https://travis-ci.org/zazuko/query-rdf-data-cube.svg?branch=master)](https://travis-ci.org/zazuko/query-rdf-data-cube) [![Coverage Status](https://coveralls.io/repos/github/zazuko/query-rdf-data-cube/badge.svg?branch=master)](https://coveralls.io/github/zazuko/query-rdf-data-cube?branch=master)
+[![npm version](https://img.shields.io/npm/v/@zazuko/query-rdf-data-cube.svg?style=flat)](https://npmjs.org/package/@zazuko/query-rdf-data-cube "View this project on npm")
+[![Build Status](https://travis-ci.org/zazuko/query-rdf-data-cube.svg?branch=master)](https://travis-ci.org/zazuko/query-rdf-data-cube)
+[![Coverage Status](https://coveralls.io/repos/github/zazuko/query-rdf-data-cube/badge.svg?branch=master)](https://coveralls.io/github/zazuko/query-rdf-data-cube?branch=master)
 
@@ -16,2 +18,4 @@ Query and explore [RDF Data Cubes](https://www.w3.org/TR/vocab-data-cube/) with a JavaScript API,
 
+Changelog: <https://github.com/zazuko/query-rdf-data-cube/blob/master/CHANGELOG.md>
+
 ## Examples
@@ -18,0 +22,0 @@

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Package has recently undergone a major refactor. It may be unstable or indicate significant internal changes. Use caution when updating to versions that include significant changes.

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Fixed alerts

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Improved metrics

Total package byte prevSize

343337

increased by36.99%

Number of package files

129

increased by10.26%

Lines of code

5317

increased by32.86%

Number of lines in readme file

124

increased by3.33%

Worsened metrics

Number of medium supply chain risk alerts

1

increased byInfinity%

No dependency changes