includes/media/XMP.php

   1 <?php
   2 /**
   3  * Reader for XMP data containing properties relevant to images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23
  24 /**
  25  * Class for reading xmp data containing properties relevant to
  26  * images, and spitting out an array that FormatExif accepts.
  27  *
  28  * Note, this is not meant to recognize every possible thing you can
  29  * encode in XMP. It should recognize all the properties we want.
  30  * For example it doesn't have support for structures with multiple
  31  * nesting levels, as none of the properties we're supporting use that
  32  * feature. If it comes across properties it doesn't recognize, it should
  33  * ignore them.
  34  *
  35  * The public methods one would call in this class are
  36  * - parse( $content )
  37  *    Reads in xmp content.
  38  *    Can potentially be called multiple times with partial data each time.
  39  * - parseExtended( $content )
  40  *    Reads XMPExtended blocks (jpeg files only).
  41  * - getResults
  42  *    Outputs a results array.
  43  *
  44  * Note XMP kind of looks like rdf. They are not the same thing - XMP is
  45  * encoded as a specific subset of rdf. This class can read XMP. It cannot
  46  * read rdf.
  47  *
  48  */
  49 class XMPReader {
  50         private $curItem = array(); // array to hold the current element (and previous element, and so on)
  51
  52         private $ancestorStruct = false; // the structure name when processing nested structures.
  53
  54         private $charContent = false; // temporary holder for character data that appears in xmp doc.
  55
  56         private $mode = array(); // stores the state the xmpreader is in (see MODE_FOO constants)
  57
  58         private $results = array(); // array to hold results
  59
  60         private $processingArray = false; // if we're doing a seq or bag.
  61
  62         private $itemLang = false; // used for lang alts only
  63
  64         private $xmlParser;
  65
  66         private $charset = false;
  67
  68         private $extendedXMPOffset = 0;
  69
  70         protected $items;
  71
  72         /**
  73          * These are various mode constants.
  74          * they are used to figure out what to do
  75          * with an element when its encountered.
  76          *
  77          * For example, MODE_IGNORE is used when processing
  78          * a property we're not interested in. So if a new
  79          * element pops up when we're in that mode, we ignore it.
  80          */
  81         const MODE_INITIAL = 0;
  82         const MODE_IGNORE = 1;
  83         const MODE_LI = 2;
  84         const MODE_LI_LANG = 3;
  85         const MODE_QDESC = 4;
  86
  87         // The following MODE constants are also used in the
  88         // $items array to denote what type of property the item is.
  89         const MODE_SIMPLE = 10;
  90         const MODE_STRUCT = 11; // structure (associative array)
  91         const MODE_SEQ = 12; // ordered list
  92         const MODE_BAG = 13; // unordered list
  93         const MODE_LANG = 14;
  94         const MODE_ALT = 15; // non-language alt. Currently not implemented, and not needed atm.
  95         const MODE_BAGSTRUCT = 16; // A BAG of Structs.
  96
  97         const NS_RDF = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
  98         const NS_XML = 'http://www.w3.org/XML/1998/namespace';
  99
 100         /**
 101          * Constructor.
 102          *
 103          * Primary job is to initialize the XMLParser
 104          */
 105         function __construct() {
 106
 107                 if ( !function_exists( 'xml_parser_create_ns' ) ) {
 108                         // this should already be checked by this point
 109                         throw new MWException( 'XMP support requires XML Parser' );
 110                 }
 111
 112                 $this->items = XMPInfo::getItems();
 113
 114                 $this->resetXMLParser();
 115         }
 116
 117         /**
 118          * Main use is if a single item has multiple xmp documents describing it.
 119          * For example in jpeg's with extendedXMP
 120          */
 121         private function resetXMLParser() {
 122
 123                 if ( $this->xmlParser ) {
 124                         //is this needed?
 125                         xml_parser_free( $this->xmlParser );
 126                 }
 127
 128                 $this->xmlParser = xml_parser_create_ns( 'UTF-8', ' ' );
 129                 xml_parser_set_option( $this->xmlParser, XML_OPTION_CASE_FOLDING, 0 );
 130                 xml_parser_set_option( $this->xmlParser, XML_OPTION_SKIP_WHITE, 1 );
 131
 132                 xml_set_element_handler( $this->xmlParser,
 133                         array( $this, 'startElement' ),
 134                         array( $this, 'endElement' ) );
 135
 136                 xml_set_character_data_handler( $this->xmlParser, array( $this, 'char' ) );
 137         }
 138
 139         /** Destroy the xml parser
 140          *
 141          * Not sure if this is actually needed.
 142          */
 143         function __destruct() {
 144                 // not sure if this is needed.
 145                 xml_parser_free( $this->xmlParser );
 146         }
 147
 148         /** Get the result array. Do some post-processing before returning
 149          * the array, and transform any metadata that is special-cased.
 150          *
 151          * @return Array array of results as an array of arrays suitable for
 152          *    FormatMetadata::getFormattedData().
 153          */
 154         public function getResults() {
 155                 // xmp-special is for metadata that affects how stuff
 156                 // is extracted. For example xmpNote:HasExtendedXMP.
 157
 158                 // It is also used to handle photoshop:AuthorsPosition
 159                 // which is weird and really part of another property,
 160                 // see 2:85 in IPTC. See also pg 21 of IPTC4XMP standard.
 161                 // The location fields also use it.
 162
 163                 $data = $this->results;
 164
 165                 wfRunHooks( 'XMPGetResults', array( &$data ) );
 166
 167                 if ( isset( $data['xmp-special']['AuthorsPosition'] )
 168                         && is_string( $data['xmp-special']['AuthorsPosition'] )
 169                         && isset( $data['xmp-general']['Artist'][0] )
 170                 ) {
 171                         // Note, if there is more than one creator,
 172                         // this only applies to first. This also will
 173                         // only apply to the dc:Creator prop, not the
 174                         // exif:Artist prop.
 175
 176                         $data['xmp-general']['Artist'][0] =
 177                                 $data['xmp-special']['AuthorsPosition'] . ', '
 178                                 . $data['xmp-general']['Artist'][0];
 179                 }
 180
 181                 // Go through the LocationShown and LocationCreated
 182                 // changing it to the non-hierarchal form used by
 183                 // the other location fields.
 184
 185                 if ( isset( $data['xmp-special']['LocationShown'][0] )
 186                         && is_array( $data['xmp-special']['LocationShown'][0] )
 187                 ) {
 188                         // the is_array is just paranoia. It should always
 189                         // be an array.
 190                         foreach ( $data['xmp-special']['LocationShown'] as $loc ) {
 191                                 if ( !is_array( $loc ) ) {
 192                                         // To avoid copying over the _type meta-fields.
 193                                         continue;
 194                                 }
 195                                 foreach ( $loc as $field => $val ) {
 196                                         $data['xmp-general'][$field . 'Dest'][] = $val;
 197                                 }
 198                         }
 199                 }
 200                 if ( isset( $data['xmp-special']['LocationCreated'][0] )
 201                         && is_array( $data['xmp-special']['LocationCreated'][0] )
 202                 ) {
 203                         // the is_array is just paranoia. It should always
 204                         // be an array.
 205                         foreach ( $data['xmp-special']['LocationCreated'] as $loc ) {
 206                                 if ( !is_array( $loc ) ) {
 207                                         // To avoid copying over the _type meta-fields.
 208                                         continue;
 209                                 }
 210                                 foreach ( $loc as $field => $val ) {
 211                                         $data['xmp-general'][$field . 'Created'][] = $val;
 212                                 }
 213                         }
 214                 }
 215
 216                 // We don't want to return the special values, since they're
 217                 // special and not info to be stored about the file.
 218                 unset( $data['xmp-special'] );
 219
 220                 // Convert GPSAltitude to negative if below sea level.
 221                 if ( isset( $data['xmp-exif']['GPSAltitudeRef'] )
 222                         && isset( $data['xmp-exif']['GPSAltitude'] )
 223                 ) {
 224
 225                         // Must convert to a real before multiplying by -1
 226                         // XMPValidate guarantees there will always be a '/' in this value.
 227                         list( $nom, $denom ) = explode( '/', $data['xmp-exif']['GPSAltitude'] );
 228                         $data['xmp-exif']['GPSAltitude'] = $nom / $denom;
 229
 230                         if ( $data['xmp-exif']['GPSAltitudeRef'] == '1' ) {
 231                                 $data['xmp-exif']['GPSAltitude'] *= -1;
 232                         }
 233                         unset( $data['xmp-exif']['GPSAltitudeRef'] );
 234                 }
 235
 236                 return $data;
 237         }
 238
 239         /**
 240          * Main function to call to parse XMP. Use getResults to
 241          * get results.
 242          *
 243          * Also catches any errors during processing, writes them to
 244          * debug log, blanks result array and returns false.
 245          *
 246          * @param string $content XMP data
 247          * @param $allOfIt Boolean: If this is all the data (true) or if its split up (false). Default true
 248          * @param $reset Boolean: does xml parser need to be reset. Default false
 249          * @throws MWException
 250          * @return Boolean success.
 251          */
 252         public function parse( $content, $allOfIt = true, $reset = false ) {
 253                 if ( $reset ) {
 254                         $this->resetXMLParser();
 255                 }
 256                 try {
 257
 258                         // detect encoding by looking for BOM which is supposed to be in processing instruction.
 259                         // see page 12 of http://www.adobe.com/devnet/xmp/pdfs/XMPSpecificationPart3.pdf
 260                         if ( !$this->charset ) {
 261                                 $bom = array();
 262                                 if ( preg_match( '/\xEF\xBB\xBF|\xFE\xFF|\x00\x00\xFE\xFF|\xFF\xFE\x00\x00|\xFF\xFE/',
 263                                         $content, $bom )
 264                                 ) {
 265                                         switch ( $bom[0] ) {
 266                                                 case "\xFE\xFF":
 267                                                         $this->charset = 'UTF-16BE';
 268                                                         break;
 269                                                 case "\xFF\xFE":
 270                                                         $this->charset = 'UTF-16LE';
 271                                                         break;
 272                                                 case "\x00\x00\xFE\xFF":
 273                                                         $this->charset = 'UTF-32BE';
 274                                                         break;
 275                                                 case "\xFF\xFE\x00\x00":
 276                                                         $this->charset = 'UTF-32LE';
 277                                                         break;
 278                                                 case "\xEF\xBB\xBF":
 279                                                         $this->charset = 'UTF-8';
 280                                                         break;
 281                                                 default:
 282                                                         //this should be impossible to get to
 283                                                         throw new MWException( "Invalid BOM" );
 284                                         }
 285                                 } else {
 286                                         // standard specifically says, if no bom assume utf-8
 287                                         $this->charset = 'UTF-8';
 288                                 }
 289                         }
 290                         if ( $this->charset !== 'UTF-8' ) {
 291                                 //don't convert if already utf-8
 292                                 wfSuppressWarnings();
 293                                 $content = iconv( $this->charset, 'UTF-8//IGNORE', $content );
 294                                 wfRestoreWarnings();
 295                         }
 296
 297                         $ok = xml_parse( $this->xmlParser, $content, $allOfIt );
 298                         if ( !$ok ) {
 299                                 $error = xml_error_string( xml_get_error_code( $this->xmlParser ) );
 300                                 $where = 'line: ' . xml_get_current_line_number( $this->xmlParser )
 301                                         . ' column: ' . xml_get_current_column_number( $this->xmlParser )
 302                                         . ' byte offset: ' . xml_get_current_byte_index( $this->xmlParser );
 303
 304                                 wfDebugLog( 'XMP', "XMPReader::parse : Error reading XMP content: $error ($where)" );
 305                                 $this->results = array(); // blank if error.
 306                                 return false;
 307                         }
 308                 } catch ( MWException $e ) {
 309                         wfDebugLog( 'XMP', 'XMP parse error: ' . $e );
 310                         $this->results = array();
 311
 312                         return false;
 313                 }
 314
 315                 return true;
 316         }
 317
 318         /** Entry point for XMPExtended blocks in jpeg files
 319          *
 320          * @todo In serious need of testing
 321          * @see http://www.adobe.ge/devnet/xmp/pdfs/XMPSpecificationPart3.pdf XMP spec part 3 page 20
 322          * @param string $content XMPExtended block minus the namespace signature
 323          * @return Boolean If it succeeded.
 324          */
 325         public function parseExtended( $content ) {
 326                 // @todo FIXME: This is untested. Hard to find example files
 327                 // or programs that make such files..
 328                 $guid = substr( $content, 0, 32 );
 329                 if ( !isset( $this->results['xmp-special']['HasExtendedXMP'] )
 330                         || $this->results['xmp-special']['HasExtendedXMP'] !== $guid
 331                 ) {
 332                         wfDebugLog( 'XMP', __METHOD__ . " Ignoring XMPExtended block due to wrong guid (guid= '$guid')" );
 333
 334                         return false;
 335                 }
 336                 $len = unpack( 'Nlength/Noffset', substr( $content, 32, 8 ) );
 337
 338                 if ( !$len || $len['length'] < 4 || $len['offset'] < 0 || $len['offset'] > $len['length'] ) {
 339                         wfDebugLog( 'XMP', __METHOD__ . 'Error reading extended XMP block, invalid length or offset.' );
 340
 341                         return false;
 342                 }
 343
 344                 // we're not very robust here. we should accept it in the wrong order. To quote
 345                 // the xmp standard:
 346                 // "A JPEG writer should write the ExtendedXMP marker segments in order, immediately following the
 347                 // StandardXMP. However, the JPEG standard does not require preservation of marker segment order. A
 348                 // robust JPEG reader should tolerate the marker segments in any order."
 349                 //
 350                 // otoh the probability that an image will have more than 128k of metadata is rather low...
 351                 // so the probability that it will have > 128k, and be in the wrong order is very low...
 352
 353                 if ( $len['offset'] !== $this->extendedXMPOffset ) {
 354                         wfDebugLog( 'XMP', __METHOD__ . 'Ignoring XMPExtended block due to wrong order. (Offset was '
 355                                 . $len['offset'] . ' but expected ' . $this->extendedXMPOffset . ')' );
 356
 357                         return false;
 358                 }
 359
 360                 if ( $len['offset'] === 0 ) {
 361                         // if we're starting the extended block, we've probably already
 362                         // done the XMPStandard block, so reset.
 363                         $this->resetXMLParser();
 364                 }
 365
 366                 $this->extendedXMPOffset += $len['length'];
 367
 368                 $actualContent = substr( $content, 40 );
 369
 370                 if ( $this->extendedXMPOffset === strlen( $actualContent ) ) {
 371                         $atEnd = true;
 372                 } else {
 373                         $atEnd = false;
 374                 }
 375
 376                 wfDebugLog( 'XMP', __METHOD__ . 'Parsing a XMPExtended block' );
 377
 378                 return $this->parse( $actualContent, $atEnd );
 379         }
 380
 381         /**
 382          * Character data handler
 383          * Called whenever character data is found in the xmp document.
 384          *
 385          * does nothing if we're in MODE_IGNORE or if the data is whitespace
 386          * throws an error if we're not in MODE_SIMPLE (as we're not allowed to have character
 387          * data in the other modes).
 388          *
 389          * As an example, this happens when we encounter XMP like:
 390          * <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio>
 391          * and are processing the 0/10 bit.
 392          *
 393          * @param $parser XMLParser reference to the xml parser
 394          * @param string $data Character data
 395          * @throws MWException on invalid data
 396          */
 397         function char( $parser, $data ) {
 398
 399                 $data = trim( $data );
 400                 if ( trim( $data ) === "" ) {
 401                         return;
 402                 }
 403
 404                 if ( !isset( $this->mode[0] ) ) {
 405                         throw new MWException( 'Unexpected character data before first rdf:Description element' );
 406                 }
 407
 408                 if ( $this->mode[0] === self::MODE_IGNORE ) {
 409                         return;
 410                 }
 411
 412                 if ( $this->mode[0] !== self::MODE_SIMPLE
 413                         && $this->mode[0] !== self::MODE_QDESC
 414                 ) {
 415                         throw new MWException( 'character data where not expected. (mode ' . $this->mode[0] . ')' );
 416                 }
 417
 418                 // to check, how does this handle w.s.
 419                 if ( $this->charContent === false ) {
 420                         $this->charContent = $data;
 421                 } else {
 422                         $this->charContent .= $data;
 423                 }
 424         }
 425
 426         /** When we hit a closing element in MODE_IGNORE
 427          * Check to see if this is the element we started to ignore,
 428          * in which case we get out of MODE_IGNORE
 429          *
 430          * @param string $elm Namespace of element followed by a space and then tag name of element.
 431          */
 432         private function endElementModeIgnore( $elm ) {
 433                 if ( $this->curItem[0] === $elm ) {
 434                         array_shift( $this->curItem );
 435                         array_shift( $this->mode );
 436                 }
 437         }
 438
 439         /**
 440          * Hit a closing element when in MODE_SIMPLE.
 441          * This generally means that we finished processing a
 442          * property value, and now have to save the result to the
 443          * results array
 444          *
 445          * For example, when processing:
 446          * <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio>
 447          * this deals with when we hit </exif:DigitalZoomRatio>.
 448          *
 449          * Or it could be if we hit the end element of a property
 450          * of a compound data structure (like a member of an array).
 451          *
 452          * @param string $elm namespace, space, and tag name.
 453          */
 454         private function endElementModeSimple( $elm ) {
 455                 if ( $this->charContent !== false ) {
 456                         if ( $this->processingArray ) {
 457                                 // if we're processing an array, use the original element
 458                                 // name instead of rdf:li.
 459                                 list( $ns, $tag ) = explode( ' ', $this->curItem[0], 2 );
 460                         } else {
 461                                 list( $ns, $tag ) = explode( ' ', $elm, 2 );
 462                         }
 463                         $this->saveValue( $ns, $tag, $this->charContent );
 464
 465                         $this->charContent = false; // reset
 466                 }
 467                 array_shift( $this->curItem );
 468                 array_shift( $this->mode );
 469         }
 470
 471         /**
 472          * Hit a closing element in MODE_STRUCT, MODE_SEQ, MODE_BAG
 473          * generally means we've finished processing a nested structure.
 474          * resets some internal variables to indicate that.
 475          *
 476          * Note this means we hit the closing element not the "</rdf:Seq>".
 477          *
 478          * @par For example, when processing:
 479          * @code{,xml}
 480          * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
 481          *   </rdf:Seq> </exif:ISOSpeedRatings>
 482          * @endcode
 483          *
 484          * This method is called when we hit the "</exif:ISOSpeedRatings>" tag.
 485          *
 486          * @param string $elm namespace . space . tag name.
 487          * @throws MWException
 488          */
 489         private function endElementNested( $elm ) {
 490
 491                 /* cur item must be the same as $elm, unless if in MODE_STRUCT
 492                    in which case it could also be rdf:Description */
 493                 if ( $this->curItem[0] !== $elm
 494                         && !( $elm === self::NS_RDF . ' Description'
 495                                 && $this->mode[0] === self::MODE_STRUCT )
 496                 ) {
 497                         throw new MWException( "nesting mismatch. got a </$elm> but expected a </" . $this->curItem[0] . '>' );
 498                 }
 499
 500                 // Validate structures.
 501                 list( $ns, $tag ) = explode( ' ', $elm, 2 );
 502                 if ( isset( $this->items[$ns][$tag]['validate'] ) ) {
 503
 504                         $info =& $this->items[$ns][$tag];
 505                         $finalName = isset( $info['map_name'] )
 506                                 ? $info['map_name'] : $tag;
 507
 508                         $validate = is_array( $info['validate'] ) ? $info['validate']
 509                                 : array( 'XMPValidate', $info['validate'] );
 510
 511                         if ( !isset( $this->results['xmp-' . $info['map_group']][$finalName] ) ) {
 512                                 // This can happen if all the members of the struct failed validation.
 513                                 wfDebugLog( 'XMP', __METHOD__ . " <$ns:$tag> has no valid members." );
 514                         } elseif ( is_callable( $validate ) ) {
 515                                 $val =& $this->results['xmp-' . $info['map_group']][$finalName];
 516                                 call_user_func_array( $validate, array( $info, &$val, false ) );
 517                                 if ( is_null( $val ) ) {
 518                                         // the idea being the validation function will unset the variable if
 519                                         // its invalid.
 520                                         wfDebugLog( 'XMP', __METHOD__ . " <$ns:$tag> failed validation." );
 521                                         unset( $this->results['xmp-' . $info['map_group']][$finalName] );
 522                                 }
 523                         } else {
 524                                 wfDebugLog( 'XMP', __METHOD__ . " Validation function for $finalName ("
 525                                         . $validate[0] . '::' . $validate[1] . '()) is not callable.' );
 526                         }
 527                 }
 528
 529                 array_shift( $this->curItem );
 530                 array_shift( $this->mode );
 531                 $this->ancestorStruct = false;
 532                 $this->processingArray = false;
 533                 $this->itemLang = false;
 534         }
 535
 536         /**
 537          * Hit a closing element in MODE_LI (either rdf:Seq, or rdf:Bag )
 538          * Add information about what type of element this is.
 539          *
 540          * Note we still have to hit the outer "</property>"
 541          *
 542          * @par For example, when processing:
 543          * @code{,xml}
 544          * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
 545          *   </rdf:Seq> </exif:ISOSpeedRatings>
 546          * @endcode
 547          *
 548          * This method is called when we hit the "</rdf:Seq>".
 549          * (For comparison, we call endElementModeSimple when we
 550          * hit the "</rdf:li>")
 551          *
 552          * @param string $elm namespace . ' ' . element name
 553          * @throws MWException
 554          */
 555         private function endElementModeLi( $elm ) {
 556
 557                 list( $ns, $tag ) = explode( ' ', $this->curItem[0], 2 );
 558                 $info = $this->items[$ns][$tag];
 559                 $finalName = isset( $info['map_name'] )
 560                         ? $info['map_name'] : $tag;
 561
 562                 array_shift( $this->mode );
 563
 564                 if ( !isset( $this->results['xmp-' . $info['map_group']][$finalName] ) ) {
 565                         wfDebugLog( 'XMP', __METHOD__ . " Empty compund element $finalName." );
 566
 567                         return;
 568                 }
 569
 570                 if ( $elm === self::NS_RDF . ' Seq' ) {
 571                         $this->results['xmp-' . $info['map_group']][$finalName]['_type'] = 'ol';
 572                 } elseif ( $elm === self::NS_RDF . ' Bag' ) {
 573                         $this->results['xmp-' . $info['map_group']][$finalName]['_type'] = 'ul';
 574                 } elseif ( $elm === self::NS_RDF . ' Alt' ) {
 575                         // extra if needed as you could theoretically have a non-language alt.
 576                         if ( $info['mode'] === self::MODE_LANG ) {
 577                                 $this->results['xmp-' . $info['map_group']][$finalName]['_type'] = 'lang';
 578                         }
 579                 } else {
 580                         throw new MWException( __METHOD__ . " expected </rdf:seq> or </rdf:bag> but instead got $elm." );
 581                 }
 582         }
 583
 584         /**
 585          * End element while in MODE_QDESC
 586          * mostly when ending an element when we have a simple value
 587          * that has qualifiers.
 588          *
 589          * Qualifiers aren't all that common, and we don't do anything
 590          * with them.
 591          *
 592          * @param string $elm namespace and element
 593          */
 594         private function endElementModeQDesc( $elm ) {
 595
 596                 if ( $elm === self::NS_RDF . ' value' ) {
 597                         list( $ns, $tag ) = explode( ' ', $this->curItem[0], 2 );
 598                         $this->saveValue( $ns, $tag, $this->charContent );
 599
 600                         return;
 601                 } else {
 602                         array_shift( $this->mode );
 603                         array_shift( $this->curItem );
 604                 }
 605         }
 606
 607         /**
 608          * Handler for hitting a closing element.
 609          *
 610          * generally just calls a helper function depending on what
 611          * mode we're in.
 612          *
 613          * Ignores the outer wrapping elements that are optional in
 614          * xmp and have no meaning.
 615          *
 616          * @param $parser XMLParser
 617          * @param string $elm namespace . ' ' . element name
 618          * @throws MWException
 619          */
 620         function endElement( $parser, $elm ) {
 621                 if ( $elm === ( self::NS_RDF . ' RDF' )
 622                         || $elm === 'adobe:ns:meta/ xmpmeta'
 623                         || $elm === 'adobe:ns:meta/ xapmeta'
 624                 ) {
 625                         // ignore these.
 626                         return;
 627                 }
 628
 629                 if ( $elm === self::NS_RDF . ' type' ) {
 630                         // these aren't really supported properly yet.
 631                         // However, it appears they almost never used.
 632                         wfDebugLog( 'XMP', __METHOD__ . ' encountered <rdf:type>' );
 633                 }
 634
 635                 if ( strpos( $elm, ' ' ) === false ) {
 636                         // This probably shouldn't happen.
 637                         // However, there is a bug in an adobe product
 638                         // that forgets the namespace on some things.
 639                         // (Luckily they are unimportant things).
 640                         wfDebugLog( 'XMP', __METHOD__ . " Encountered </$elm> which has no namespace. Skipping." );
 641
 642                         return;
 643                 }
 644
 645                 if ( count( $this->mode[0] ) === 0 ) {
 646                         // This should never ever happen and means
 647                         // there is a pretty major bug in this class.
 648                         throw new MWException( 'Encountered end element with no mode' );
 649                 }
 650
 651                 if ( count( $this->curItem ) == 0 && $this->mode[0] !== self::MODE_INITIAL ) {
 652                         // just to be paranoid. Should always have a curItem, except for initially
 653                         // (aka during MODE_INITAL).
 654                         throw new MWException( "Hit end element </$elm> but no curItem" );
 655                 }
 656
 657                 switch ( $this->mode[0] ) {
 658                         case self::MODE_IGNORE:
 659                                 $this->endElementModeIgnore( $elm );
 660                                 break;
 661                         case self::MODE_SIMPLE:
 662                                 $this->endElementModeSimple( $elm );
 663                                 break;
 664                         case self::MODE_STRUCT:
 665                         case self::MODE_SEQ:
 666                         case self::MODE_BAG:
 667                         case self::MODE_LANG:
 668                         case self::MODE_BAGSTRUCT:
 669                                 $this->endElementNested( $elm );
 670                                 break;
 671                         case self::MODE_INITIAL:
 672                                 if ( $elm === self::NS_RDF . ' Description' ) {
 673                                         array_shift( $this->mode );
 674                                 } else {
 675                                         throw new MWException( 'Element ended unexpectedly while in MODE_INITIAL' );
 676                                 }
 677                                 break;
 678                         case self::MODE_LI:
 679                         case self::MODE_LI_LANG:
 680                                 $this->endElementModeLi( $elm );
 681                                 break;
 682                         case self::MODE_QDESC:
 683                                 $this->endElementModeQDesc( $elm );
 684                                 break;
 685                         default:
 686                                 wfDebugLog( 'XMP', __METHOD__ . " no mode (elm = $elm)" );
 687                                 break;
 688                 }
 689         }
 690
 691         /**
 692          * Hit an opening element while in MODE_IGNORE
 693          *
 694          * XMP is extensible, so ignore any tag we don't understand.
 695          *
 696          * Mostly ignores, unless we encounter the element that we are ignoring.
 697          * in which case we add it to the item stack, so we can ignore things
 698          * that are nested, correctly.
 699          *
 700          * @param string $elm namespace . ' ' . tag name
 701          */
 702         private function startElementModeIgnore( $elm ) {
 703                 if ( $elm === $this->curItem[0] ) {
 704                         array_unshift( $this->curItem, $elm );
 705                         array_unshift( $this->mode, self::MODE_IGNORE );
 706                 }
 707         }
 708
 709         /**
 710          *  Start element in MODE_BAG (unordered array)
 711          * this should always be <rdf:Bag>
 712          *
 713          * @param string $elm namespace . ' ' . tag
 714          * @throws MWException if we have an element that's not <rdf:Bag>
 715          */
 716         private function startElementModeBag( $elm ) {
 717                 if ( $elm === self::NS_RDF . ' Bag' ) {
 718                         array_unshift( $this->mode, self::MODE_LI );
 719                 } else {
 720                         throw new MWException( "Expected <rdf:Bag> but got $elm." );
 721                 }
 722         }
 723
 724         /**
 725          * Start element in MODE_SEQ (ordered array)
 726          * this should always be <rdf:Seq>
 727          *
 728          * @param string $elm namespace . ' ' . tag
 729          * @throws MWException if we have an element that's not <rdf:Seq>
 730          */
 731         private function startElementModeSeq( $elm ) {
 732                 if ( $elm === self::NS_RDF . ' Seq' ) {
 733                         array_unshift( $this->mode, self::MODE_LI );
 734                 } elseif ( $elm === self::NS_RDF . ' Bag' ) {
 735                         # bug 27105
 736                         wfDebugLog( 'XMP', __METHOD__ . ' Expected an rdf:Seq, but got an rdf:Bag. Pretending'
 737                                 . ' it is a Seq, since some buggy software is known to screw this up.' );
 738                         array_unshift( $this->mode, self::MODE_LI );
 739                 } else {
 740                         throw new MWException( "Expected <rdf:Seq> but got $elm." );
 741                 }
 742         }
 743
 744         /**
 745          * Start element in MODE_LANG (language alternative)
 746          * this should always be <rdf:Alt>
 747          *
 748          * This tag tends to be used for metadata like describe this
 749          * picture, which can be translated into multiple languages.
 750          *
 751          * XMP supports non-linguistic alternative selections,
 752          * which are really only used for thumbnails, which
 753          * we don't care about.
 754          *
 755          * @param string $elm namespace . ' ' . tag
 756          * @throws MWException if we have an element that's not <rdf:Alt>
 757          */
 758         private function startElementModeLang( $elm ) {
 759                 if ( $elm === self::NS_RDF . ' Alt' ) {
 760                         array_unshift( $this->mode, self::MODE_LI_LANG );
 761                 } else {
 762                         throw new MWException( "Expected <rdf:Seq> but got $elm." );
 763                 }
 764         }
 765
 766         /**
 767          * Handle an opening element when in MODE_SIMPLE
 768          *
 769          * This should not happen often. This is for if a simple element
 770          * already opened has a child element. Could happen for a
 771          * qualified element.
 772          *
 773          * For example:
 774          * <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value>
 775          *   <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description>
 776          *   </exif:DigitalZoomRatio>
 777          *
 778          * This method is called when processing the <rdf:Description> element
 779          *
 780          * @param string $elm namespace and tag names separated by space.
 781          * @param array $attribs Attributes of the element.
 782          * @throws MWException
 783          */
 784         private function startElementModeSimple( $elm, $attribs ) {
 785                 if ( $elm === self::NS_RDF . ' Description' ) {
 786                         // If this value has qualifiers
 787                         array_unshift( $this->mode, self::MODE_QDESC );
 788                         array_unshift( $this->curItem, $this->curItem[0] );
 789
 790                         if ( isset( $attribs[self::NS_RDF . ' value'] ) ) {
 791                                 list( $ns, $tag ) = explode( ' ', $this->curItem[0], 2 );
 792                                 $this->saveValue( $ns, $tag, $attribs[self::NS_RDF . ' value'] );
 793                         }
 794                 } elseif ( $elm === self::NS_RDF . ' value' ) {
 795                         // This should not be here.
 796                         throw new MWException( __METHOD__ . ' Encountered <rdf:value> where it was unexpected.' );
 797                 } else {
 798                         // something else we don't recognize, like a qualifier maybe.
 799                         wfDebugLog( 'XMP', __METHOD__ . " Encountered element <$elm> where only expecting character data as value of " . $this->curItem[0] );
 800                         array_unshift( $this->mode, self::MODE_IGNORE );
 801                         array_unshift( $this->curItem, $elm );
 802                 }
 803         }
 804
 805         /**
 806          * Start an element when in MODE_QDESC.
 807          * This generally happens when a simple element has an inner
 808          * rdf:Description to hold qualifier elements.
 809          *
 810          * For example in:
 811          * <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value>
 812          *   <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description>
 813          *   </exif:DigitalZoomRatio>
 814          * Called when processing the <rdf:value> or <foo:someQualifier>.
 815          *
 816          * @param string $elm namespace and tag name separated by a space.
 817          *
 818          */
 819         private function startElementModeQDesc( $elm ) {
 820                 if ( $elm === self::NS_RDF . ' value' ) {
 821                         return; // do nothing
 822                 } else {
 823                         // otherwise its a qualifier, which we ignore
 824                         array_unshift( $this->mode, self::MODE_IGNORE );
 825                         array_unshift( $this->curItem, $elm );
 826                 }
 827         }
 828
 829         /**
 830          * Starting an element when in MODE_INITIAL
 831          * This usually happens when we hit an element inside
 832          * the outer rdf:Description
 833          *
 834          * This is generally where most properties start.
 835          *
 836          * @param string $ns Namespace
 837          * @param string $tag tag name (without namespace prefix)
 838          * @param array $attribs array of attributes
 839          * @throws MWException
 840          */
 841         private function startElementModeInitial( $ns, $tag, $attribs ) {
 842                 if ( $ns !== self::NS_RDF ) {
 843
 844                         if ( isset( $this->items[$ns][$tag] ) ) {
 845                                 if ( isset( $this->items[$ns][$tag]['structPart'] ) ) {
 846                                         // If this element is supposed to appear only as
 847                                         // a child of a structure, but appears here (not as
 848                                         // a child of a struct), then something weird is
 849                                         // happening, so ignore this element and its children.
 850
 851                                         wfDebugLog( 'XMP', "Encountered <$ns:$tag> outside"
 852                                                 . " of its expected parent. Ignoring." );
 853
 854                                         array_unshift( $this->mode, self::MODE_IGNORE );
 855                                         array_unshift( $this->curItem, $ns . ' ' . $tag );
 856
 857                                         return;
 858                                 }
 859                                 $mode = $this->items[$ns][$tag]['mode'];
 860                                 array_unshift( $this->mode, $mode );
 861                                 array_unshift( $this->curItem, $ns . ' ' . $tag );
 862                                 if ( $mode === self::MODE_STRUCT ) {
 863                                         $this->ancestorStruct = isset( $this->items[$ns][$tag]['map_name'] )
 864                                                 ? $this->items[$ns][$tag]['map_name'] : $tag;
 865                                 }
 866                                 if ( $this->charContent !== false ) {
 867                                         // Something weird.
 868                                         // Should not happen in valid XMP.
 869                                         throw new MWException( 'tag nested in non-whitespace characters.' );
 870                                 }
 871                         } else {
 872                                 // This element is not on our list of allowed elements so ignore.
 873                                 wfDebugLog( 'XMP', __METHOD__ . " Ignoring unrecognized element <$ns:$tag>." );
 874                                 array_unshift( $this->mode, self::MODE_IGNORE );
 875                                 array_unshift( $this->curItem, $ns . ' ' . $tag );
 876
 877                                 return;
 878                         }
 879                 }
 880                 // process attributes
 881                 $this->doAttribs( $attribs );
 882         }
 883
 884         /**
 885          * Hit an opening element when in a Struct (MODE_STRUCT)
 886          * This is generally for fields of a compound property.
 887          *
 888          * Example of a struct (abbreviated; flash has more properties):
 889          *
 890          * <exif:Flash> <rdf:Description> <exif:Fired>True</exif:Fired>
 891          *  <exif:Mode>1</exif:Mode></rdf:Description></exif:Flash>
 892          *
 893          * or:
 894          *
 895          * <exif:Flash rdf:parseType='Resource'> <exif:Fired>True</exif:Fired>
 896          *  <exif:Mode>1</exif:Mode></exif:Flash>
 897          *
 898          * @param string $ns namespace
 899          * @param string $tag tag name (no ns)
 900          * @param array $attribs array of attribs w/ values.
 901          * @throws MWException
 902          */
 903         private function startElementModeStruct( $ns, $tag, $attribs ) {
 904                 if ( $ns !== self::NS_RDF ) {
 905
 906                         if ( isset( $this->items[$ns][$tag] ) ) {
 907                                 if ( isset( $this->items[$ns][$this->ancestorStruct]['children'] )
 908                                         && !isset( $this->items[$ns][$this->ancestorStruct]['children'][$tag] )
 909                                 ) {
 910                                         // This assumes that we don't have inter-namespace nesting
 911                                         // which we don't in all the properties we're interested in.
 912                                         throw new MWException( " <$tag> appeared nested in <" . $this->ancestorStruct
 913                                                 . "> where it is not allowed." );
 914                                 }
 915                                 array_unshift( $this->mode, $this->items[$ns][$tag]['mode'] );
 916                                 array_unshift( $this->curItem, $ns . ' ' . $tag );
 917                                 if ( $this->charContent !== false ) {
 918                                         // Something weird.
 919                                         // Should not happen in valid XMP.
 920                                         throw new MWException( "tag <$tag> nested in non-whitespace characters (" . $this->charContent . ")." );
 921                                 }
 922                         } else {
 923                                 array_unshift( $this->mode, self::MODE_IGNORE );
 924                                 array_unshift( $this->curItem, $elm );
 925
 926                                 return;
 927                         }
 928                 }
 929
 930                 if ( $ns === self::NS_RDF && $tag === 'Description' ) {
 931                         $this->doAttribs( $attribs );
 932                         array_unshift( $this->mode, self::MODE_STRUCT );
 933                         array_unshift( $this->curItem, $this->curItem[0] );
 934                 }
 935         }
 936
 937         /**
 938          * opening element in MODE_LI
 939          * process elements of arrays.
 940          *
 941          * Example:
 942          * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
 943          *   </rdf:Seq> </exif:ISOSpeedRatings>
 944          * This method is called when we hit the <rdf:li> element.
 945          *
 946          * @param string $elm namespace . ' ' . tagname
 947          * @param array $attribs Attributes. (needed for BAGSTRUCTS)
 948          * @throws MWException if gets a tag other than <rdf:li>
 949          */
 950         private function startElementModeLi( $elm, $attribs ) {
 951                 if ( ( $elm ) !== self::NS_RDF . ' li' ) {
 952                         throw new MWException( "<rdf:li> expected but got $elm." );
 953                 }
 954
 955                 if ( !isset( $this->mode[1] ) ) {
 956                         // This should never ever ever happen. Checking for it
 957                         // to be paranoid.
 958                         throw new MWException( 'In mode Li, but no 2xPrevious mode!' );
 959                 }
 960
 961                 if ( $this->mode[1] === self::MODE_BAGSTRUCT ) {
 962                         // This list item contains a compound (STRUCT) value.
 963                         array_unshift( $this->mode, self::MODE_STRUCT );
 964                         array_unshift( $this->curItem, $elm );
 965                         $this->processingArray = true;
 966
 967                         if ( !isset( $this->curItem[1] ) ) {
 968                                 // be paranoid.
 969                                 throw new MWException( 'Can not find parent of BAGSTRUCT.' );
 970                         }
 971                         list( $curNS, $curTag ) = explode( ' ', $this->curItem[1] );
 972                         $this->ancestorStruct = isset( $this->items[$curNS][$curTag]['map_name'] )
 973                                 ? $this->items[$curNS][$curTag]['map_name'] : $curTag;
 974
 975                         $this->doAttribs( $attribs );
 976                 } else {
 977                         // Normal BAG or SEQ containing simple values.
 978                         array_unshift( $this->mode, self::MODE_SIMPLE );
 979                         // need to add curItem[0] on again since one is for the specific item
 980                         // and one is for the entire group.
 981                         array_unshift( $this->curItem, $this->curItem[0] );
 982                         $this->processingArray = true;
 983                 }
 984         }
 985
 986         /**
 987          * Opening element in MODE_LI_LANG.
 988          * process elements of language alternatives
 989          *
 990          * Example:
 991          * <dc:title> <rdf:Alt> <rdf:li xml:lang="x-default">My house
 992          *  </rdf:li> </rdf:Alt> </dc:title>
 993          *
 994          * This method is called when we hit the <rdf:li> element.
 995          *
 996          * @param string $elm namespace . ' ' . tag
 997          * @param array $attribs array of elements (most importantly xml:lang)
 998          * @throws MWException if gets a tag other than <rdf:li> or if no xml:lang
 999          */
1000         private function startElementModeLiLang( $elm, $attribs ) {
1001                 if ( $elm !== self::NS_RDF . ' li' ) {
1002                         throw new MWException( __METHOD__ . " <rdf:li> expected but got $elm." );
1003                 }
1004                 if ( !isset( $attribs[self::NS_XML . ' lang'] )
1005                         || !preg_match( '/^[-A-Za-z0-9]{2,}$/D', $attribs[self::NS_XML . ' lang'] )
1006                 ) {
1007                         throw new MWException( __METHOD__
1008                                 . " <rdf:li> did not contain, or has invalid xml:lang attribute in lang alternative" );
1009                 }
1010
1011                 // Lang is case-insensitive.
1012                 $this->itemLang = strtolower( $attribs[self::NS_XML . ' lang'] );
1013
1014                 // need to add curItem[0] on again since one is for the specific item
1015                 // and one is for the entire group.
1016                 array_unshift( $this->curItem, $this->curItem[0] );
1017                 array_unshift( $this->mode, self::MODE_SIMPLE );
1018                 $this->processingArray = true;
1019         }
1020
1021         /**
1022          * Hits an opening element.
1023          * Generally just calls a helper based on what MODE we're in.
1024          * Also does some initial set up for the wrapper element
1025          *
1026          * @param $parser XMLParser
1027          * @param string $elm namespace "<space>" element
1028          * @param array $attribs attribute name => value
1029          * @throws MWException
1030          */
1031         function startElement( $parser, $elm, $attribs ) {
1032
1033                 if ( $elm === self::NS_RDF . ' RDF'
1034                         || $elm === 'adobe:ns:meta/ xmpmeta'
1035                         || $elm === 'adobe:ns:meta/ xapmeta'
1036                 ) {
1037                         /* ignore. */
1038                         return;
1039                 } elseif ( $elm === self::NS_RDF . ' Description' ) {
1040                         if ( count( $this->mode ) === 0 ) {
1041                                 // outer rdf:desc
1042                                 array_unshift( $this->mode, self::MODE_INITIAL );
1043                         }
1044                 } elseif ( $elm === self::NS_RDF . ' type' ) {
1045                         // This doesn't support rdf:type properly.
1046                         // In practise I have yet to see a file that
1047                         // uses this element, however it is mentioned
1048                         // on page 25 of part 1 of the xmp standard.
1049                         //
1050                         // also it seems as if exiv2 and exiftool do not support
1051                         // this either (That or I misunderstand the standard)
1052                         wfDebugLog( 'XMP', __METHOD__ . ' Encountered <rdf:type> which isn\'t currently supported' );
1053                 }
1054
1055                 if ( strpos( $elm, ' ' ) === false ) {
1056                         // This probably shouldn't happen.
1057                         wfDebugLog( 'XMP', __METHOD__ . " Encountered <$elm> which has no namespace. Skipping." );
1058
1059                         return;
1060                 }
1061
1062                 list( $ns, $tag ) = explode( ' ', $elm, 2 );
1063
1064                 if ( count( $this->mode ) === 0 ) {
1065                         // This should not happen.
1066                         throw new MWException( 'Error extracting XMP, '
1067                                 . "encountered <$elm> with no mode" );
1068                 }
1069
1070                 switch ( $this->mode[0] ) {
1071                         case self::MODE_IGNORE:
1072                                 $this->startElementModeIgnore( $elm );
1073                                 break;
1074                         case self::MODE_SIMPLE:
1075                                 $this->startElementModeSimple( $elm, $attribs );
1076                                 break;
1077                         case self::MODE_INITIAL:
1078                                 $this->startElementModeInitial( $ns, $tag, $attribs );
1079                                 break;
1080                         case self::MODE_STRUCT:
1081                                 $this->startElementModeStruct( $ns, $tag, $attribs );
1082                                 break;
1083                         case self::MODE_BAG:
1084                         case self::MODE_BAGSTRUCT:
1085                                 $this->startElementModeBag( $elm );
1086                                 break;
1087                         case self::MODE_SEQ:
1088                                 $this->startElementModeSeq( $elm );
1089                                 break;
1090                         case self::MODE_LANG:
1091                                 $this->startElementModeLang( $elm );
1092                                 break;
1093                         case self::MODE_LI_LANG:
1094                                 $this->startElementModeLiLang( $elm, $attribs );
1095                                 break;
1096                         case self::MODE_LI:
1097                                 $this->startElementModeLi( $elm, $attribs );
1098                                 break;
1099                         case self::MODE_QDESC:
1100                                 $this->startElementModeQDesc( $elm );
1101                                 break;
1102                         default:
1103                                 throw new MWException( 'StartElement in unknown mode: ' . $this->mode[0] );
1104                 }
1105         }
1106
1107         /**
1108          * Process attributes.
1109          * Simple values can be stored as either a tag or attribute
1110          *
1111          * Often the initial "<rdf:Description>" tag just has all the simple
1112          * properties as attributes.
1113          *
1114          * @par Example:
1115          * @code
1116          * <rdf:Description rdf:about="" xmlns:exif="http://ns.adobe.com/exif/1.0/" exif:DigitalZoomRatio="0/10">
1117          * @endcode
1118          *
1119          * @param array $attribs attribute=>value array.
1120          * @throws MWException
1121          */
1122         private function doAttribs( $attribs ) {
1123
1124                 // first check for rdf:parseType attribute, as that can change
1125                 // how the attributes are interperted.
1126
1127                 if ( isset( $attribs[self::NS_RDF . ' parseType'] )
1128                         && $attribs[self::NS_RDF . ' parseType'] === 'Resource'
1129                         && $this->mode[0] === self::MODE_SIMPLE
1130                 ) {
1131                         // this is equivalent to having an inner rdf:Description
1132                         $this->mode[0] = self::MODE_QDESC;
1133                 }
1134                 foreach ( $attribs as $name => $val ) {
1135                         if ( strpos( $name, ' ' ) === false ) {
1136                                 // This shouldn't happen, but so far some old software forgets namespace
1137                                 // on rdf:about.
1138                                 wfDebugLog( 'XMP', __METHOD__ . ' Encountered non-namespaced attribute: '
1139                                         . " $name=\"$val\". Skipping. " );
1140                                 continue;
1141                         }
1142                         list( $ns, $tag ) = explode( ' ', $name, 2 );
1143                         if ( $ns === self::NS_RDF ) {
1144                                 if ( $tag === 'value' || $tag === 'resource' ) {
1145                                         // resource is for url.
1146                                         // value attribute is a weird way of just putting the contents.
1147                                         $this->char( $this->xmlParser, $val );
1148                                 }
1149                         } elseif ( isset( $this->items[$ns][$tag] ) ) {
1150                                 if ( $this->mode[0] === self::MODE_SIMPLE ) {
1151                                         throw new MWException( __METHOD__
1152                                                 . " $ns:$tag found as attribute where not allowed" );
1153                                 }
1154                                 $this->saveValue( $ns, $tag, $val );
1155                         } else {
1156                                 wfDebugLog( 'XMP', __METHOD__ . " Ignoring unrecognized element <$ns:$tag>." );
1157                         }
1158                 }
1159         }
1160
1161         /**
1162          * Given an extracted value, save it to results array
1163          *
1164          * note also uses $this->ancestorStruct and
1165          * $this->processingArray to determine what name to
1166          * save the value under. (in addition to $tag).
1167          *
1168          * @param string $ns namespace of tag this is for
1169          * @param string $tag tag name
1170          * @param string $val value to save
1171          */
1172         private function saveValue( $ns, $tag, $val ) {
1173
1174                 $info =& $this->items[$ns][$tag];
1175                 $finalName = isset( $info['map_name'] )
1176                         ? $info['map_name'] : $tag;
1177                 if ( isset( $info['validate'] ) ) {
1178                         $validate = is_array( $info['validate'] ) ? $info['validate']
1179                                 : array( 'XMPValidate', $info['validate'] );
1180
1181                         if ( is_callable( $validate ) ) {
1182                                 call_user_func_array( $validate, array( $info, &$val, true ) );
1183                                 // the reasoning behind using &$val instead of using the return value
1184                                 // is to be consistent between here and validating structures.
1185                                 if ( is_null( $val ) ) {
1186                                         wfDebugLog( 'XMP', __METHOD__ . " <$ns:$tag> failed validation." );
1187
1188                                         return;
1189                                 }
1190                         } else {
1191                                 wfDebugLog( 'XMP', __METHOD__ . " Validation function for $finalName ("
1192                                         . $validate[0] . '::' . $validate[1] . '()) is not callable.' );
1193                         }
1194                 }
1195
1196                 if ( $this->ancestorStruct && $this->processingArray ) {
1197                         // Aka both an array and a struct. ( self::MODE_BAGSTRUCT )
1198                         $this->results['xmp-' . $info['map_group']][$this->ancestorStruct][][$finalName] = $val;
1199                 } elseif ( $this->ancestorStruct ) {
1200                         $this->results['xmp-' . $info['map_group']][$this->ancestorStruct][$finalName] = $val;
1201                 } elseif ( $this->processingArray ) {
1202                         if ( $this->itemLang === false ) {
1203                                 // normal array
1204                                 $this->results['xmp-' . $info['map_group']][$finalName][] = $val;
1205                         } else {
1206                                 // lang array.
1207                                 $this->results['xmp-' . $info['map_group']][$finalName][$this->itemLang] = $val;
1208                         }
1209                 } else {
1210                         $this->results['xmp-' . $info['map_group']][$finalName] = $val;
1211                 }
1212         }
1213 }