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 $data;
  41         }
  42
  43         public static function normalize($json)
  44         {
  45                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
  46
  47                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
  48
  49                 return jsonld_normalize($jsonobj, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads'));
  50         }
  51
  52         public static function compact($json)
  53         {
  54                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
  55
  56                 $context = (object)['as' => 'https://www.w3.org/ns/activitystreams',
  57                         'w3sec' => 'https://w3id.org/security',
  58                         'ostatus' => (object)['@id' => 'http://ostatus.org#', '@type' => '@id'],
  59                         'vcard' => (object)['@id' => 'http://www.w3.org/2006/vcard/ns#', '@type' => '@id'],
  60                         'uuid' => (object)['@id' => 'http://schema.org/identifier', '@type' => '@id']];
  61
  62                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
  63
  64                 $compacted = jsonld_compact($jsonobj, $context);
  65
  66                 return json_decode(json_encode($compacted, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), true);
  67         }
  68
  69         public static function fetchElement($array, $element, $key, $type = null, $type_value = null)
  70         {
  71                 if (empty($array)) {
  72                         return false;
  73                 }
  74
  75                 if (empty($array[$element])) {
  76                         return false;
  77                 }
  78
  79                 if (is_string($array[$element])) {
  80                         return $array[$element];
  81                 }
  82
  83                 if (is_null($type_value)) {
  84                         if (!empty($array[$element][$key])) {
  85                                 return $array[$element][$key];
  86                         }
  87
  88                         if (!empty($array[$element][0][$key])) {
  89                                 return $array[$element][0][$key];
  90                         }
  91
  92                         return false;
  93                 }
  94
  95                 if (!empty($array[$element][$key]) && !empty($array[$element][$type]) && ($array[$element][$type] == $type_value)) {
  96                         return $array[$element][$key];
  97                 }
  98
  99                 /// @todo Add array search
 100
 101                 return false;
 102         }
 103 }