Arc2JsonLdConverter

Author: Lukas Rosenstock

.gitignore

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+vendor

Arc2JsonLdConverter.php

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+<?php
+
+namespace CloudObjects\Utilities\RDF;
+
+use ML\IRI\IRI;
+use ML\JsonLD\JsonLD, ML\JsonLD\Quad, ML\JsonLD\TypedValue, ML\JsonLD\RdfConstants;
+
+class Arc2JsonLdConverter {
+
+  /**
+   * Converts an array of ARC2 triples into an array of RDF quads
+   * in JsonLD library format.
+   * @param array $triples ARC2 triples
+   */
+  public static function triplesToQuads(array $triples) {
+    $quads = array();
+    foreach ($triples as $t) {
+      $quads[] = new Quad(new IRI($t['s']), new IRI($t['p']),
+      ($t['o_type'] == 'uri') ? new IRI($t['o']) : new TypedValue($t['o'],
+      (isset($t['o_datatype']) && $t['o_datatype']!='') ? $t['o_datatype'] : RdfConstants::XSD_STRING));
+    }
+
+    return $quads;
+  }
+
+  /**
+   * Converts an ARC2 index into an array of RDF quads in JsonLD
+   * library format.
+   * @param array $index ARC2 index
+   */
+  public static function indexToQuads(array $index) {
+    $quads = array();
+    foreach ($index as $subject => $predicates) {
+      foreach ($predicates as $predicate => $objects) {
+        foreach ($objects as $object) {
+          $quads[] = new Quad(new IRI($subject),
+            new IRI($predicate),
+            ($object['type']!='literal')
+              ? new IRI($object['value']) : new TypedValue($object['value'],
+            (isset($object['datatype']) && $object['datatype']!='')
+              ? $object['datatype'] : RdfConstants::XSD_STRING));
+        }
+      }
+    }
+    return $quads;
+  }
+
+  /**
+   * Converts an array of RDF quads in JsonLD library format into
+   * an array of ARC2 triples.
+   * @param array $quads JsonLD quads
+   */
+  public static function quadsToTriples(array $quads) {
+    $arcTriples = array();
+    foreach ($quads as $q) {
+      $arcTriples[] = array(
+        's' => (string)$q->getSubject(),
+        'p' => (string)$q->getProperty(),
+        'o' => (is_a($q->getObject(), 'ML\JsonLD\TypedValue')) ? $q->getObject()->getValue() : (string)$q->getObject(),
+        'o_type' => (is_a($q->getObject(), 'ML\JsonLD\TypedValue')) ? 'literal' : 'uri'
+      );
+    }
+    return $arcTriples;
+  }
+
+  /**
+   * Converts an array of RDF quads in JsonLD library format into
+   * an ARC2 index.
+   * @param array $quads JsonLD quads
+   */
+  public static function quadsToIndex(array $quads) {
+    return \ARC2::getSimpleIndex(self::quadsToTriples($quads), 0);
+  }
+
+  /**
+   * Converts any JsonLD into an array of ARC2 triples.
+   * @param string|array|object $jsonLd JsonLD content
+   */
+  public static function jsonLdToTriples($jsonLd) {
+    if (is_array($jsonLd)) $jsonLd = (object)$jsonLd;
+    return self::quadsToTriples(JsonLD::toRdf($jsonLd));
+  }
+
+  /**
+   * Converts any JsonLD into an ARC2 index.
+   * @param string|array|object $jsonLd JsonLD content
+   */
+  public static function jsonLdToIndex($jsonLd) {
+    if (is_array($jsonLd)) $jsonLd = (object)$jsonLd;
+    return self::quadsToIndex(JsonLD::toRdf($jsonLd));
+  }
+
+}

composer.json

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+{
+  "name": "cloudobjects/rdfutilities",
+  "description": "ARC2JsonLD Helper Class",
+  "keywords": ["cloudobjects", "rdf", "json-ld", "arc2"],
+  "homepage": "https://github.com/CloudObjects/RDFUtilities",
+  "license": "MPL",
+  "authors": [
+    {
+      "name": "Lukas Rosenstock"
+    }
+  ],
+  "require": {
+    "semsol/arc2" : "v2.1.0",
+    "ml/json-ld" : ">=1.0.3"
+  },
+  "autoload": {
+    "psr-4": {
+      "CloudObjects\\Utilities\\RDF\\" : ""
+    }
+  }
+}