src/Util/JsonLD.php

   1 <?php
   2 /**
   3  * @file src/Util/JsonLD.php
   4  */
   5 namespace Friendica\Util;
   6
   7 use Friendica\Core\Cache;
   8 use digitalbazaar\jsonld as DBJsonLD;
   9
  10 /**
  11  * @brief This class contain methods to work with JsonLD data
  12  */
  13 class JsonLD
  14 {
  15         public static function documentLoader($url)
  16         {
  17                 $recursion = 0;
  18
  19                 $x = debug_backtrace();
  20                 if ($x) {
  21                         foreach ($x as $n) {
  22                                 if ($n['function'] === __FUNCTION__)  {
  23                                         $recursion ++;
  24                                 }
  25                         }
  26                 }
  27
  28                 if ($recursion > 5) {
  29                         logger('jsonld bomb detected at: ' . $url);
  30                         exit();
  31                 }
  32
  33                 $result = Cache::get('documentLoader:' . $url);
  34                 if (!is_null($result)) {
  35                         return $result;
  36                 }
  37
  38                 $data = jsonld_default_document_loader($url);
  39                 Cache::set('documentLoader:' . $url, $data, CACHE_DAY);
  40                 return $data;
  41         }
  42
  43         private static function objectify($element)
  44         {
  45                 if (is_array($element)) {
  46                         $keys = array_keys($element);
  47                         if (is_int(array_pop($keys))) {
  48                                 return array_map('objectify', $element);
  49                         } else {
  50                                 return (object)array_map('objectify', $element);
  51                         }
  52                 } else {
  53                         return $element;
  54                 }
  55         }
  56
  57         public static function normalize($json)
  58         {
  59                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
  60
  61 //              $jsonobj = array_map('Friendica\Util\JsonLD::objectify', $json);
  62                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
  63
  64                 return jsonld_normalize($jsonobj, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads'));
  65         }
  66
  67         public static function compact($json)
  68         {
  69                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
  70
  71                 $context = (object)['as' => 'https://www.w3.org/ns/activitystreams',
  72                         'w3sec' => 'https://w3id.org/security',
  73                         'ostatus' => (object)['@id' => 'http://ostatus.org#', '@type' => '@id'],
  74                         'vcard' => (object)['@id' => 'http://www.w3.org/2006/vcard/ns#', '@type' => '@id'],
  75                         'uuid' => (object)['@id' => 'http://schema.org/identifier', '@type' => '@id']];
  76
  77                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
  78
  79                 $compacted = jsonld_compact($jsonobj, $context);
  80
  81                 return json_decode(json_encode($compacted, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), true);
  82         }
  83
  84         public static function fetchElement($array, $element, $key, $type = null, $type_value = null)
  85         {
  86                 if (empty($array)) {
  87                         return false;
  88                 }
  89
  90                 if (empty($array[$element])) {
  91                         return false;
  92                 }
  93
  94                 if (is_string($array[$element])) {
  95                         return $array[$element];
  96                 }
  97
  98                 if (is_null($type_value)) {
  99                         if (!empty($array[$element][$key])) {
 100                                 return $array[$element][$key];
 101                         }
 102
 103                         if (!empty($array[$element][0][$key])) {
 104                                 return $array[$element][0][$key];
 105                         }
 106
 107                         return false;
 108                 }
 109
 110                 if (!empty($array[$element][$key]) && !empty($array[$element][$type]) && ($array[$element][$type] == $type_value)) {
 111                         return $array[$element][$key];
 112                 }
 113
 114                 /// @todo Add array search
 115
 116                 return false;
 117         }
 118 }