3 * Reader for XMP data containing properties relevant to images.
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.
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.
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
24 use Psr\Log\LoggerAwareInterface
;
25 use Psr\Log\LoggerInterface
;
26 use Psr\Log\NullLogger
;
29 * Class for reading xmp data containing properties relevant to
30 * images, and spitting out an array that FormatMetadata accepts.
32 * Note, this is not meant to recognize every possible thing you can
33 * encode in XMP. It should recognize all the properties we want.
34 * For example it doesn't have support for structures with multiple
35 * nesting levels, as none of the properties we're supporting use that
36 * feature. If it comes across properties it doesn't recognize, it should
39 * The public methods one would call in this class are
41 * Reads in xmp content.
42 * Can potentially be called multiple times with partial data each time.
43 * - parseExtended( $content )
44 * Reads XMPExtended blocks (jpeg files only).
46 * Outputs a results array.
48 * Note XMP kind of looks like rdf. They are not the same thing - XMP is
49 * encoded as a specific subset of rdf. This class can read XMP. It cannot
53 class XMPReader
implements LoggerAwareInterface
{
54 /** @var array XMP item configuration array */
57 /** @var array Array to hold the current element (and previous element, and so on) */
58 private $curItem = array();
60 /** @var bool|string The structure name when processing nested structures. */
61 private $ancestorStruct = false;
63 /** @var bool|string Temporary holder for character data that appears in xmp doc. */
64 private $charContent = false;
66 /** @var array Stores the state the xmpreader is in (see MODE_FOO constants) */
67 private $mode = array();
69 /** @var array Array to hold results */
70 private $results = array();
72 /** @var bool If we're doing a seq or bag. */
73 private $processingArray = false;
75 /** @var bool|string Used for lang alts only */
76 private $itemLang = false;
78 /** @var resource A resource handle for the XML parser */
81 /** @var bool|string Character set like 'UTF-8' */
82 private $charset = false;
85 private $extendedXMPOffset = 0;
87 /** @var int Flag determining if the XMP is safe to parse **/
88 private $parsable = 0;
90 /** @var string Buffer of XML to parse **/
91 private $xmlParsableBuffer = '';
94 * These are various mode constants.
95 * they are used to figure out what to do
96 * with an element when its encountered.
98 * For example, MODE_IGNORE is used when processing
99 * a property we're not interested in. So if a new
100 * element pops up when we're in that mode, we ignore it.
102 const MODE_INITIAL
= 0;
103 const MODE_IGNORE
= 1;
105 const MODE_LI_LANG
= 3;
106 const MODE_QDESC
= 4;
108 // The following MODE constants are also used in the
109 // $items array to denote what type of property the item is.
110 const MODE_SIMPLE
= 10;
111 const MODE_STRUCT
= 11; // structure (associative array)
112 const MODE_SEQ
= 12; // ordered list
113 const MODE_BAG
= 13; // unordered list
114 const MODE_LANG
= 14;
115 const MODE_ALT
= 15; // non-language alt. Currently not implemented, and not needed atm.
116 const MODE_BAGSTRUCT
= 16; // A BAG of Structs.
118 const NS_RDF
= 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
119 const NS_XML
= 'http://www.w3.org/XML/1998/namespace';
121 // States used while determining if XML is safe to parse
122 const PARSABLE_UNKNOWN
= 0;
123 const PARSABLE_OK
= 1;
124 const PARSABLE_BUFFERING
= 2;
125 const PARSABLE_NO
= 3;
128 * @var LoggerInterface
135 * Primary job is to initialize the XMLParser
137 function __construct( LoggerInterface
$logger = null ) {
139 if ( !function_exists( 'xml_parser_create_ns' ) ) {
140 // this should already be checked by this point
141 throw new RuntimeException( 'XMP support requires XML Parser' );
144 $this->setLogger( $logger );
146 $this->setLogger( new NullLogger() );
149 $this->items
= XMPInfo
::getItems();
151 $this->resetXMLParser();
154 public function setLogger( LoggerInterface
$logger ) {
155 $this->logger
= $logger;
159 * free the XML parser.
161 * @note It is unclear to me if we really need to do this ourselves
162 * or if php garbage collection will automatically free the xmlParser
163 * when it is no longer needed.
165 private function destroyXMLParser() {
166 if ( $this->xmlParser
) {
167 xml_parser_free( $this->xmlParser
);
168 $this->xmlParser
= null;
173 * Main use is if a single item has multiple xmp documents describing it.
174 * For example in jpeg's with extendedXMP
176 private function resetXMLParser() {
178 $this->destroyXMLParser();
180 $this->xmlParser
= xml_parser_create_ns( 'UTF-8', ' ' );
181 xml_parser_set_option( $this->xmlParser
, XML_OPTION_CASE_FOLDING
, 0 );
182 xml_parser_set_option( $this->xmlParser
, XML_OPTION_SKIP_WHITE
, 1 );
184 xml_set_element_handler( $this->xmlParser
,
185 array( $this, 'startElement' ),
186 array( $this, 'endElement' ) );
188 xml_set_character_data_handler( $this->xmlParser
, array( $this, 'char' ) );
190 $this->parsable
= self
::PARSABLE_UNKNOWN
;
191 $this->xmlParsableBuffer
= '';
195 * Check if this instance supports using this class
197 public static function isSupported() {
198 return function_exists( 'xml_parser_create_ns' ) && class_exists( 'XMLReader' );
201 /** Get the result array. Do some post-processing before returning
202 * the array, and transform any metadata that is special-cased.
204 * @return array Array of results as an array of arrays suitable for
205 * FormatMetadata::getFormattedData().
207 public function getResults() {
208 // xmp-special is for metadata that affects how stuff
209 // is extracted. For example xmpNote:HasExtendedXMP.
211 // It is also used to handle photoshop:AuthorsPosition
212 // which is weird and really part of another property,
213 // see 2:85 in IPTC. See also pg 21 of IPTC4XMP standard.
214 // The location fields also use it.
216 $data = $this->results
;
218 if ( isset( $data['xmp-special']['AuthorsPosition'] )
219 && is_string( $data['xmp-special']['AuthorsPosition'] )
220 && isset( $data['xmp-general']['Artist'][0] )
222 // Note, if there is more than one creator,
223 // this only applies to first. This also will
224 // only apply to the dc:Creator prop, not the
227 $data['xmp-general']['Artist'][0] =
228 $data['xmp-special']['AuthorsPosition'] . ', '
229 . $data['xmp-general']['Artist'][0];
232 // Go through the LocationShown and LocationCreated
233 // changing it to the non-hierarchal form used by
234 // the other location fields.
236 if ( isset( $data['xmp-special']['LocationShown'][0] )
237 && is_array( $data['xmp-special']['LocationShown'][0] )
239 // the is_array is just paranoia. It should always
241 foreach ( $data['xmp-special']['LocationShown'] as $loc ) {
242 if ( !is_array( $loc ) ) {
243 // To avoid copying over the _type meta-fields.
246 foreach ( $loc as $field => $val ) {
247 $data['xmp-general'][$field . 'Dest'][] = $val;
251 if ( isset( $data['xmp-special']['LocationCreated'][0] )
252 && is_array( $data['xmp-special']['LocationCreated'][0] )
254 // the is_array is just paranoia. It should always
256 foreach ( $data['xmp-special']['LocationCreated'] as $loc ) {
257 if ( !is_array( $loc ) ) {
258 // To avoid copying over the _type meta-fields.
261 foreach ( $loc as $field => $val ) {
262 $data['xmp-general'][$field . 'Created'][] = $val;
267 // We don't want to return the special values, since they're
268 // special and not info to be stored about the file.
269 unset( $data['xmp-special'] );
271 // Convert GPSAltitude to negative if below sea level.
272 if ( isset( $data['xmp-exif']['GPSAltitudeRef'] )
273 && isset( $data['xmp-exif']['GPSAltitude'] )
276 // Must convert to a real before multiplying by -1
277 // XMPValidate guarantees there will always be a '/' in this value.
278 list( $nom, $denom ) = explode( '/', $data['xmp-exif']['GPSAltitude'] );
279 $data['xmp-exif']['GPSAltitude'] = $nom / $denom;
281 if ( $data['xmp-exif']['GPSAltitudeRef'] == '1' ) {
282 $data['xmp-exif']['GPSAltitude'] *= -1;
284 unset( $data['xmp-exif']['GPSAltitudeRef'] );
291 * Main function to call to parse XMP. Use getResults to
294 * Also catches any errors during processing, writes them to
295 * debug log, blanks result array and returns false.
297 * @param string $content XMP data
298 * @param bool $allOfIt If this is all the data (true) or if its split up (false). Default true
299 * @throws RuntimeException
300 * @return bool Success.
302 public function parse( $content, $allOfIt = true ) {
303 if ( !$this->xmlParser
) {
304 $this->resetXMLParser();
308 // detect encoding by looking for BOM which is supposed to be in processing instruction.
309 // see page 12 of http://www.adobe.com/devnet/xmp/pdfs/XMPSpecificationPart3.pdf
310 if ( !$this->charset
) {
312 if ( preg_match( '/\xEF\xBB\xBF|\xFE\xFF|\x00\x00\xFE\xFF|\xFF\xFE\x00\x00|\xFF\xFE/',
317 $this->charset
= 'UTF-16BE';
320 $this->charset
= 'UTF-16LE';
322 case "\x00\x00\xFE\xFF":
323 $this->charset
= 'UTF-32BE';
325 case "\xFF\xFE\x00\x00":
326 $this->charset
= 'UTF-32LE';
329 $this->charset
= 'UTF-8';
332 //this should be impossible to get to
333 throw new RuntimeException( "Invalid BOM" );
336 // standard specifically says, if no bom assume utf-8
337 $this->charset
= 'UTF-8';
340 if ( $this->charset
!== 'UTF-8' ) {
341 //don't convert if already utf-8
342 MediaWiki\
suppressWarnings();
343 $content = iconv( $this->charset
, 'UTF-8//IGNORE', $content );
344 MediaWiki\restoreWarnings
();
347 // Ensure the XMP block does not have an xml doctype declaration, which
348 // could declare entities unsafe to parse with xml_parse (T85848/T71210).
349 if ( $this->parsable
!== self
::PARSABLE_OK
) {
350 if ( $this->parsable
=== self
::PARSABLE_NO
) {
351 throw new Exception( 'Unsafe doctype declaration in XML.' );
354 $content = $this->xmlParsableBuffer
. $content;
355 if ( !$this->checkParseSafety( $content ) ) {
356 if ( !$allOfIt && $this->parsable
!== self
::PARSABLE_NO
) {
357 // parse wasn't Unsuccessful yet, so return true
361 $msg = ( $this->parsable
=== self
::PARSABLE_NO
) ?
362 'Unsafe doctype declaration in XML.' :
363 'No root element found in XML.';
364 throw new Exception( $msg );
368 $ok = xml_parse( $this->xmlParser
, $content, $allOfIt );
370 $error = xml_error_string( xml_get_error_code( $this->xmlParser
) );
371 $where = 'line: ' . xml_get_current_line_number( $this->xmlParser
)
372 . ' column: ' . xml_get_current_column_number( $this->xmlParser
)
373 . ' byte offset: ' . xml_get_current_byte_index( $this->xmlParser
);
375 $this->logger
->info( "XMPReader::parse : Error reading XMP content: $error ($where)" );
376 $this->results
= array(); // blank if error.
377 $this->destroyXMLParser();
380 } catch ( Exception
$e ) {
381 $this->logger
->info( 'XMP parse error: ' . $e );
382 $this->results
= array();
385 $this->destroyXMLParser();
390 $this->destroyXMLParser();
396 /** Entry point for XMPExtended blocks in jpeg files
398 * @todo In serious need of testing
399 * @see http://www.adobe.ge/devnet/xmp/pdfs/XMPSpecificationPart3.pdf XMP spec part 3 page 20
400 * @param string $content XMPExtended block minus the namespace signature
401 * @return bool If it succeeded.
403 public function parseExtended( $content ) {
404 // @todo FIXME: This is untested. Hard to find example files
405 // or programs that make such files..
406 $guid = substr( $content, 0, 32 );
407 if ( !isset( $this->results
['xmp-special']['HasExtendedXMP'] )
408 ||
$this->results
['xmp-special']['HasExtendedXMP'] !== $guid
410 $this->logger
->info( __METHOD__
.
411 " Ignoring XMPExtended block due to wrong guid (guid= '$guid')" );
415 $len = unpack( 'Nlength/Noffset', substr( $content, 32, 8 ) );
417 if ( !$len ||
$len['length'] < 4 ||
$len['offset'] < 0 ||
$len['offset'] > $len['length'] ) {
418 $this->logger
->info( __METHOD__
. 'Error reading extended XMP block, invalid length or offset.' );
423 // we're not very robust here. we should accept it in the wrong order.
424 // To quote the XMP standard:
425 // "A JPEG writer should write the ExtendedXMP marker segments in order,
426 // immediately following the StandardXMP. However, the JPEG standard
427 // does not require preservation of marker segment order. A robust JPEG
428 // reader should tolerate the marker segments in any order."
430 // otoh the probability that an image will have more than 128k of
431 // metadata is rather low... so the probability that it will have
432 // > 128k, and be in the wrong order is very low...
434 if ( $len['offset'] !== $this->extendedXMPOffset
) {
435 $this->logger
->info( __METHOD__
. 'Ignoring XMPExtended block due to wrong order. (Offset was '
436 . $len['offset'] . ' but expected ' . $this->extendedXMPOffset
. ')' );
441 if ( $len['offset'] === 0 ) {
442 // if we're starting the extended block, we've probably already
443 // done the XMPStandard block, so reset.
444 $this->resetXMLParser();
447 $this->extendedXMPOffset +
= $len['length'];
449 $actualContent = substr( $content, 40 );
451 if ( $this->extendedXMPOffset
=== strlen( $actualContent ) ) {
457 $this->logger
->debug( __METHOD__
. 'Parsing a XMPExtended block' );
459 return $this->parse( $actualContent, $atEnd );
463 * Character data handler
464 * Called whenever character data is found in the xmp document.
466 * does nothing if we're in MODE_IGNORE or if the data is whitespace
467 * throws an error if we're not in MODE_SIMPLE (as we're not allowed to have character
468 * data in the other modes).
470 * As an example, this happens when we encounter XMP like:
471 * <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio>
472 * and are processing the 0/10 bit.
474 * @param XMLParser $parser XMLParser reference to the xml parser
475 * @param string $data Character data
476 * @throws RuntimeException On invalid data
478 function char( $parser, $data ) {
480 $data = trim( $data );
481 if ( trim( $data ) === "" ) {
485 if ( !isset( $this->mode
[0] ) ) {
486 throw new RuntimeException( 'Unexpected character data before first rdf:Description element' );
489 if ( $this->mode
[0] === self
::MODE_IGNORE
) {
493 if ( $this->mode
[0] !== self
::MODE_SIMPLE
494 && $this->mode
[0] !== self
::MODE_QDESC
496 throw new RuntimeException( 'character data where not expected. (mode ' . $this->mode
[0] . ')' );
499 // to check, how does this handle w.s.
500 if ( $this->charContent
=== false ) {
501 $this->charContent
= $data;
503 $this->charContent
.= $data;
508 * Check if a block of XML is safe to pass to xml_parse, i.e. doesn't
509 * contain a doctype declaration which could contain a dos attack if we
510 * parse it and expand internal entities (T85848).
512 * @param string $content xml string to check for parse safety
513 * @return bool true if the xml is safe to parse, false otherwise
515 private function checkParseSafety( $content ) {
516 $reader = new XMLReader();
519 // For XMLReader to parse incomplete/invalid XML, it has to be open()'ed
520 // instead of using XML().
522 'data://text/plain,' . urlencode( $content ),
524 LIBXML_NOERROR | LIBXML_NOWARNING | LIBXML_NONET
527 $oldDisable = libxml_disable_entity_loader( true );
528 /** @noinspection PhpUnusedLocalVariableInspection */
529 $reset = new ScopedCallback(
530 'libxml_disable_entity_loader',
533 $reader->setParserProperty( XMLReader
::SUBST_ENTITIES
, false );
535 // Even with LIBXML_NOWARNING set, XMLReader::read gives a warning
536 // when parsing truncated XML, which causes unit tests to fail.
537 MediaWiki\
suppressWarnings();
538 while ( $reader->read() ) {
539 if ( $reader->nodeType
=== XMLReader
::ELEMENT
) {
540 // Reached the first element without hitting a doctype declaration
541 $this->parsable
= self
::PARSABLE_OK
;
545 if ( $reader->nodeType
=== XMLReader
::DOC_TYPE
) {
546 $this->parsable
= self
::PARSABLE_NO
;
551 MediaWiki\restoreWarnings
();
553 if ( !is_null( $result ) ) {
557 // Reached the end of the parsable xml without finding an element
558 // or doctype. Buffer and try again.
559 $this->parsable
= self
::PARSABLE_BUFFERING
;
560 $this->xmlParsableBuffer
= $content;
564 /** When we hit a closing element in MODE_IGNORE
565 * Check to see if this is the element we started to ignore,
566 * in which case we get out of MODE_IGNORE
568 * @param string $elm Namespace of element followed by a space and then tag name of element.
570 private function endElementModeIgnore( $elm ) {
571 if ( $this->curItem
[0] === $elm ) {
572 array_shift( $this->curItem
);
573 array_shift( $this->mode
);
578 * Hit a closing element when in MODE_SIMPLE.
579 * This generally means that we finished processing a
580 * property value, and now have to save the result to the
583 * For example, when processing:
584 * <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio>
585 * this deals with when we hit </exif:DigitalZoomRatio>.
587 * Or it could be if we hit the end element of a property
588 * of a compound data structure (like a member of an array).
590 * @param string $elm Namespace, space, and tag name.
592 private function endElementModeSimple( $elm ) {
593 if ( $this->charContent
!== false ) {
594 if ( $this->processingArray
) {
595 // if we're processing an array, use the original element
596 // name instead of rdf:li.
597 list( $ns, $tag ) = explode( ' ', $this->curItem
[0], 2 );
599 list( $ns, $tag ) = explode( ' ', $elm, 2 );
601 $this->saveValue( $ns, $tag, $this->charContent
);
603 $this->charContent
= false; // reset
605 array_shift( $this->curItem
);
606 array_shift( $this->mode
);
610 * Hit a closing element in MODE_STRUCT, MODE_SEQ, MODE_BAG
611 * generally means we've finished processing a nested structure.
612 * resets some internal variables to indicate that.
614 * Note this means we hit the closing element not the "</rdf:Seq>".
616 * @par For example, when processing:
618 * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
619 * </rdf:Seq> </exif:ISOSpeedRatings>
622 * This method is called when we hit the "</exif:ISOSpeedRatings>" tag.
624 * @param string $elm Namespace . space . tag name.
625 * @throws RuntimeException
627 private function endElementNested( $elm ) {
629 /* cur item must be the same as $elm, unless if in MODE_STRUCT
630 in which case it could also be rdf:Description */
631 if ( $this->curItem
[0] !== $elm
632 && !( $elm === self
::NS_RDF
. ' Description'
633 && $this->mode
[0] === self
::MODE_STRUCT
)
635 throw new RuntimeException( "nesting mismatch. got a </$elm> but expected a </" .
636 $this->curItem
[0] . '>' );
639 // Validate structures.
640 list( $ns, $tag ) = explode( ' ', $elm, 2 );
641 if ( isset( $this->items
[$ns][$tag]['validate'] ) ) {
642 $info =& $this->items
[$ns][$tag];
643 $finalName = isset( $info['map_name'] )
644 ?
$info['map_name'] : $tag;
646 if ( is_array( $info['validate'] ) ) {
647 $validate = $info['validate'];
649 $validator = new XMPValidate( $this->logger
);
650 $validate = array( $validator, $info['validate'] );
653 if ( !isset( $this->results
['xmp-' . $info['map_group']][$finalName] ) ) {
654 // This can happen if all the members of the struct failed validation.
655 $this->logger
->debug( __METHOD__
. " <$ns:$tag> has no valid members." );
656 } elseif ( is_callable( $validate ) ) {
657 $val =& $this->results
['xmp-' . $info['map_group']][$finalName];
658 call_user_func_array( $validate, array( $info, &$val, false ) );
659 if ( is_null( $val ) ) {
660 // the idea being the validation function will unset the variable if
662 $this->logger
->info( __METHOD__
. " <$ns:$tag> failed validation." );
663 unset( $this->results
['xmp-' . $info['map_group']][$finalName] );
666 $this->logger
->warning( __METHOD__
. " Validation function for $finalName ("
667 . $validate[0] . '::' . $validate[1] . '()) is not callable.' );
671 array_shift( $this->curItem
);
672 array_shift( $this->mode
);
673 $this->ancestorStruct
= false;
674 $this->processingArray
= false;
675 $this->itemLang
= false;
679 * Hit a closing element in MODE_LI (either rdf:Seq, or rdf:Bag )
680 * Add information about what type of element this is.
682 * Note we still have to hit the outer "</property>"
684 * @par For example, when processing:
686 * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
687 * </rdf:Seq> </exif:ISOSpeedRatings>
690 * This method is called when we hit the "</rdf:Seq>".
691 * (For comparison, we call endElementModeSimple when we
692 * hit the "</rdf:li>")
694 * @param string $elm Namespace . ' ' . element name
695 * @throws RuntimeException
697 private function endElementModeLi( $elm ) {
699 list( $ns, $tag ) = explode( ' ', $this->curItem
[0], 2 );
700 $info = $this->items
[$ns][$tag];
701 $finalName = isset( $info['map_name'] )
702 ?
$info['map_name'] : $tag;
704 array_shift( $this->mode
);
706 if ( !isset( $this->results
['xmp-' . $info['map_group']][$finalName] ) ) {
707 $this->logger
->debug( __METHOD__
. " Empty compund element $finalName." );
712 if ( $elm === self
::NS_RDF
. ' Seq' ) {
713 $this->results
['xmp-' . $info['map_group']][$finalName]['_type'] = 'ol';
714 } elseif ( $elm === self
::NS_RDF
. ' Bag' ) {
715 $this->results
['xmp-' . $info['map_group']][$finalName]['_type'] = 'ul';
716 } elseif ( $elm === self
::NS_RDF
. ' Alt' ) {
717 // extra if needed as you could theoretically have a non-language alt.
718 if ( $info['mode'] === self
::MODE_LANG
) {
719 $this->results
['xmp-' . $info['map_group']][$finalName]['_type'] = 'lang';
722 throw new RuntimeException( __METHOD__
. " expected </rdf:seq> or </rdf:bag> but instead got $elm." );
727 * End element while in MODE_QDESC
728 * mostly when ending an element when we have a simple value
729 * that has qualifiers.
731 * Qualifiers aren't all that common, and we don't do anything
734 * @param string $elm Namespace and element
736 private function endElementModeQDesc( $elm ) {
738 if ( $elm === self
::NS_RDF
. ' value' ) {
739 list( $ns, $tag ) = explode( ' ', $this->curItem
[0], 2 );
740 $this->saveValue( $ns, $tag, $this->charContent
);
744 array_shift( $this->mode
);
745 array_shift( $this->curItem
);
750 * Handler for hitting a closing element.
752 * generally just calls a helper function depending on what
755 * Ignores the outer wrapping elements that are optional in
756 * xmp and have no meaning.
758 * @param XMLParser $parser
759 * @param string $elm Namespace . ' ' . element name
760 * @throws RuntimeException
762 function endElement( $parser, $elm ) {
763 if ( $elm === ( self
::NS_RDF
. ' RDF' )
764 ||
$elm === 'adobe:ns:meta/ xmpmeta'
765 ||
$elm === 'adobe:ns:meta/ xapmeta'
771 if ( $elm === self
::NS_RDF
. ' type' ) {
772 // these aren't really supported properly yet.
773 // However, it appears they almost never used.
774 $this->logger
->info( __METHOD__
. ' encountered <rdf:type>' );
777 if ( strpos( $elm, ' ' ) === false ) {
778 // This probably shouldn't happen.
779 // However, there is a bug in an adobe product
780 // that forgets the namespace on some things.
781 // (Luckily they are unimportant things).
782 $this->logger
->info( __METHOD__
. " Encountered </$elm> which has no namespace. Skipping." );
787 if ( count( $this->mode
[0] ) === 0 ) {
788 // This should never ever happen and means
789 // there is a pretty major bug in this class.
790 throw new RuntimeException( 'Encountered end element with no mode' );
793 if ( count( $this->curItem
) == 0 && $this->mode
[0] !== self
::MODE_INITIAL
) {
794 // just to be paranoid. Should always have a curItem, except for initially
795 // (aka during MODE_INITAL).
796 throw new RuntimeException( "Hit end element </$elm> but no curItem" );
799 switch ( $this->mode
[0] ) {
800 case self
::MODE_IGNORE
:
801 $this->endElementModeIgnore( $elm );
803 case self
::MODE_SIMPLE
:
804 $this->endElementModeSimple( $elm );
806 case self
::MODE_STRUCT
:
809 case self
::MODE_LANG
:
810 case self
::MODE_BAGSTRUCT
:
811 $this->endElementNested( $elm );
813 case self
::MODE_INITIAL
:
814 if ( $elm === self
::NS_RDF
. ' Description' ) {
815 array_shift( $this->mode
);
817 throw new RuntimeException( 'Element ended unexpectedly while in MODE_INITIAL' );
821 case self
::MODE_LI_LANG
:
822 $this->endElementModeLi( $elm );
824 case self
::MODE_QDESC
:
825 $this->endElementModeQDesc( $elm );
828 $this->logger
->warning( __METHOD__
. " no mode (elm = $elm)" );
834 * Hit an opening element while in MODE_IGNORE
836 * XMP is extensible, so ignore any tag we don't understand.
838 * Mostly ignores, unless we encounter the element that we are ignoring.
839 * in which case we add it to the item stack, so we can ignore things
840 * that are nested, correctly.
842 * @param string $elm Namespace . ' ' . tag name
844 private function startElementModeIgnore( $elm ) {
845 if ( $elm === $this->curItem
[0] ) {
846 array_unshift( $this->curItem
, $elm );
847 array_unshift( $this->mode
, self
::MODE_IGNORE
);
852 * Start element in MODE_BAG (unordered array)
853 * this should always be <rdf:Bag>
855 * @param string $elm Namespace . ' ' . tag
856 * @throws RuntimeException If we have an element that's not <rdf:Bag>
858 private function startElementModeBag( $elm ) {
859 if ( $elm === self
::NS_RDF
. ' Bag' ) {
860 array_unshift( $this->mode
, self
::MODE_LI
);
862 throw new RuntimeException( "Expected <rdf:Bag> but got $elm." );
867 * Start element in MODE_SEQ (ordered array)
868 * this should always be <rdf:Seq>
870 * @param string $elm Namespace . ' ' . tag
871 * @throws RuntimeException If we have an element that's not <rdf:Seq>
873 private function startElementModeSeq( $elm ) {
874 if ( $elm === self
::NS_RDF
. ' Seq' ) {
875 array_unshift( $this->mode
, self
::MODE_LI
);
876 } elseif ( $elm === self
::NS_RDF
. ' Bag' ) {
878 $this->logger
->info( __METHOD__
. ' Expected an rdf:Seq, but got an rdf:Bag. Pretending'
879 . ' it is a Seq, since some buggy software is known to screw this up.' );
880 array_unshift( $this->mode
, self
::MODE_LI
);
882 throw new RuntimeException( "Expected <rdf:Seq> but got $elm." );
887 * Start element in MODE_LANG (language alternative)
888 * this should always be <rdf:Alt>
890 * This tag tends to be used for metadata like describe this
891 * picture, which can be translated into multiple languages.
893 * XMP supports non-linguistic alternative selections,
894 * which are really only used for thumbnails, which
895 * we don't care about.
897 * @param string $elm Namespace . ' ' . tag
898 * @throws RuntimeException If we have an element that's not <rdf:Alt>
900 private function startElementModeLang( $elm ) {
901 if ( $elm === self
::NS_RDF
. ' Alt' ) {
902 array_unshift( $this->mode
, self
::MODE_LI_LANG
);
904 throw new RuntimeException( "Expected <rdf:Seq> but got $elm." );
909 * Handle an opening element when in MODE_SIMPLE
911 * This should not happen often. This is for if a simple element
912 * already opened has a child element. Could happen for a
916 * <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value>
917 * <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description>
918 * </exif:DigitalZoomRatio>
920 * This method is called when processing the <rdf:Description> element
922 * @param string $elm Namespace and tag names separated by space.
923 * @param array $attribs Attributes of the element.
924 * @throws RuntimeException
926 private function startElementModeSimple( $elm, $attribs ) {
927 if ( $elm === self
::NS_RDF
. ' Description' ) {
928 // If this value has qualifiers
929 array_unshift( $this->mode
, self
::MODE_QDESC
);
930 array_unshift( $this->curItem
, $this->curItem
[0] );
932 if ( isset( $attribs[self
::NS_RDF
. ' value'] ) ) {
933 list( $ns, $tag ) = explode( ' ', $this->curItem
[0], 2 );
934 $this->saveValue( $ns, $tag, $attribs[self
::NS_RDF
. ' value'] );
936 } elseif ( $elm === self
::NS_RDF
. ' value' ) {
937 // This should not be here.
938 throw new RuntimeException( __METHOD__
. ' Encountered <rdf:value> where it was unexpected.' );
940 // something else we don't recognize, like a qualifier maybe.
941 $this->logger
->info( __METHOD__
.
942 " Encountered element <$elm> where only expecting character data as value of " .
944 array_unshift( $this->mode
, self
::MODE_IGNORE
);
945 array_unshift( $this->curItem
, $elm );
950 * Start an element when in MODE_QDESC.
951 * This generally happens when a simple element has an inner
952 * rdf:Description to hold qualifier elements.
955 * <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value>
956 * <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description>
957 * </exif:DigitalZoomRatio>
958 * Called when processing the <rdf:value> or <foo:someQualifier>.
960 * @param string $elm Namespace and tag name separated by a space.
963 private function startElementModeQDesc( $elm ) {
964 if ( $elm === self
::NS_RDF
. ' value' ) {
965 return; // do nothing
967 // otherwise its a qualifier, which we ignore
968 array_unshift( $this->mode
, self
::MODE_IGNORE
);
969 array_unshift( $this->curItem
, $elm );
974 * Starting an element when in MODE_INITIAL
975 * This usually happens when we hit an element inside
976 * the outer rdf:Description
978 * This is generally where most properties start.
980 * @param string $ns Namespace
981 * @param string $tag Tag name (without namespace prefix)
982 * @param array $attribs Array of attributes
983 * @throws RuntimeException
985 private function startElementModeInitial( $ns, $tag, $attribs ) {
986 if ( $ns !== self
::NS_RDF
) {
988 if ( isset( $this->items
[$ns][$tag] ) ) {
989 if ( isset( $this->items
[$ns][$tag]['structPart'] ) ) {
990 // If this element is supposed to appear only as
991 // a child of a structure, but appears here (not as
992 // a child of a struct), then something weird is
993 // happening, so ignore this element and its children.
995 $this->logger
->warning( "Encountered <$ns:$tag> outside"
996 . " of its expected parent. Ignoring." );
998 array_unshift( $this->mode
, self
::MODE_IGNORE
);
999 array_unshift( $this->curItem
, $ns . ' ' . $tag );
1003 $mode = $this->items
[$ns][$tag]['mode'];
1004 array_unshift( $this->mode
, $mode );
1005 array_unshift( $this->curItem
, $ns . ' ' . $tag );
1006 if ( $mode === self
::MODE_STRUCT
) {
1007 $this->ancestorStruct
= isset( $this->items
[$ns][$tag]['map_name'] )
1008 ?
$this->items
[$ns][$tag]['map_name'] : $tag;
1010 if ( $this->charContent
!== false ) {
1012 // Should not happen in valid XMP.
1013 throw new RuntimeException( 'tag nested in non-whitespace characters.' );
1016 // This element is not on our list of allowed elements so ignore.
1017 $this->logger
->debug( __METHOD__
. " Ignoring unrecognized element <$ns:$tag>." );
1018 array_unshift( $this->mode
, self
::MODE_IGNORE
);
1019 array_unshift( $this->curItem
, $ns . ' ' . $tag );
1024 // process attributes
1025 $this->doAttribs( $attribs );
1029 * Hit an opening element when in a Struct (MODE_STRUCT)
1030 * This is generally for fields of a compound property.
1032 * Example of a struct (abbreviated; flash has more properties):
1034 * <exif:Flash> <rdf:Description> <exif:Fired>True</exif:Fired>
1035 * <exif:Mode>1</exif:Mode></rdf:Description></exif:Flash>
1039 * <exif:Flash rdf:parseType='Resource'> <exif:Fired>True</exif:Fired>
1040 * <exif:Mode>1</exif:Mode></exif:Flash>
1042 * @param string $ns Namespace
1043 * @param string $tag Tag name (no ns)
1044 * @param array $attribs Array of attribs w/ values.
1045 * @throws RuntimeException
1047 private function startElementModeStruct( $ns, $tag, $attribs ) {
1048 if ( $ns !== self
::NS_RDF
) {
1050 if ( isset( $this->items
[$ns][$tag] ) ) {
1051 if ( isset( $this->items
[$ns][$this->ancestorStruct
]['children'] )
1052 && !isset( $this->items
[$ns][$this->ancestorStruct
]['children'][$tag] )
1054 // This assumes that we don't have inter-namespace nesting
1055 // which we don't in all the properties we're interested in.
1056 throw new RuntimeException( " <$tag> appeared nested in <" . $this->ancestorStruct
1057 . "> where it is not allowed." );
1059 array_unshift( $this->mode
, $this->items
[$ns][$tag]['mode'] );
1060 array_unshift( $this->curItem
, $ns . ' ' . $tag );
1061 if ( $this->charContent
!== false ) {
1063 // Should not happen in valid XMP.
1064 throw new RuntimeException( "tag <$tag> nested in non-whitespace characters (" .
1065 $this->charContent
. ")." );
1068 array_unshift( $this->mode
, self
::MODE_IGNORE
);
1069 array_unshift( $this->curItem
, $elm );
1075 if ( $ns === self
::NS_RDF
&& $tag === 'Description' ) {
1076 $this->doAttribs( $attribs );
1077 array_unshift( $this->mode
, self
::MODE_STRUCT
);
1078 array_unshift( $this->curItem
, $this->curItem
[0] );
1083 * opening element in MODE_LI
1084 * process elements of arrays.
1087 * <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>
1088 * </rdf:Seq> </exif:ISOSpeedRatings>
1089 * This method is called when we hit the <rdf:li> element.
1091 * @param string $elm Namespace . ' ' . tagname
1092 * @param array $attribs Attributes. (needed for BAGSTRUCTS)
1093 * @throws RuntimeException If gets a tag other than <rdf:li>
1095 private function startElementModeLi( $elm, $attribs ) {
1096 if ( ( $elm ) !== self
::NS_RDF
. ' li' ) {
1097 throw new RuntimeException( "<rdf:li> expected but got $elm." );
1100 if ( !isset( $this->mode
[1] ) ) {
1101 // This should never ever ever happen. Checking for it
1103 throw new RuntimeException( 'In mode Li, but no 2xPrevious mode!' );
1106 if ( $this->mode
[1] === self
::MODE_BAGSTRUCT
) {
1107 // This list item contains a compound (STRUCT) value.
1108 array_unshift( $this->mode
, self
::MODE_STRUCT
);
1109 array_unshift( $this->curItem
, $elm );
1110 $this->processingArray
= true;
1112 if ( !isset( $this->curItem
[1] ) ) {
1114 throw new RuntimeException( 'Can not find parent of BAGSTRUCT.' );
1116 list( $curNS, $curTag ) = explode( ' ', $this->curItem
[1] );
1117 $this->ancestorStruct
= isset( $this->items
[$curNS][$curTag]['map_name'] )
1118 ?
$this->items
[$curNS][$curTag]['map_name'] : $curTag;
1120 $this->doAttribs( $attribs );
1122 // Normal BAG or SEQ containing simple values.
1123 array_unshift( $this->mode
, self
::MODE_SIMPLE
);
1124 // need to add curItem[0] on again since one is for the specific item
1125 // and one is for the entire group.
1126 array_unshift( $this->curItem
, $this->curItem
[0] );
1127 $this->processingArray
= true;
1132 * Opening element in MODE_LI_LANG.
1133 * process elements of language alternatives
1136 * <dc:title> <rdf:Alt> <rdf:li xml:lang="x-default">My house
1137 * </rdf:li> </rdf:Alt> </dc:title>
1139 * This method is called when we hit the <rdf:li> element.
1141 * @param string $elm Namespace . ' ' . tag
1142 * @param array $attribs Array of elements (most importantly xml:lang)
1143 * @throws RuntimeException If gets a tag other than <rdf:li> or if no xml:lang
1145 private function startElementModeLiLang( $elm, $attribs ) {
1146 if ( $elm !== self
::NS_RDF
. ' li' ) {
1147 throw new RuntimeException( __METHOD__
. " <rdf:li> expected but got $elm." );
1149 if ( !isset( $attribs[self
::NS_XML
. ' lang'] )
1150 ||
!preg_match( '/^[-A-Za-z0-9]{2,}$/D', $attribs[self
::NS_XML
. ' lang'] )
1152 throw new RuntimeException( __METHOD__
1153 . " <rdf:li> did not contain, or has invalid xml:lang attribute in lang alternative" );
1156 // Lang is case-insensitive.
1157 $this->itemLang
= strtolower( $attribs[self
::NS_XML
. ' lang'] );
1159 // need to add curItem[0] on again since one is for the specific item
1160 // and one is for the entire group.
1161 array_unshift( $this->curItem
, $this->curItem
[0] );
1162 array_unshift( $this->mode
, self
::MODE_SIMPLE
);
1163 $this->processingArray
= true;
1167 * Hits an opening element.
1168 * Generally just calls a helper based on what MODE we're in.
1169 * Also does some initial set up for the wrapper element
1171 * @param XMLParser $parser
1172 * @param string $elm Namespace "<space>" element
1173 * @param array $attribs Attribute name => value
1174 * @throws RuntimeException
1176 function startElement( $parser, $elm, $attribs ) {
1178 if ( $elm === self
::NS_RDF
. ' RDF'
1179 ||
$elm === 'adobe:ns:meta/ xmpmeta'
1180 ||
$elm === 'adobe:ns:meta/ xapmeta'
1184 } elseif ( $elm === self
::NS_RDF
. ' Description' ) {
1185 if ( count( $this->mode
) === 0 ) {
1187 array_unshift( $this->mode
, self
::MODE_INITIAL
);
1189 } elseif ( $elm === self
::NS_RDF
. ' type' ) {
1190 // This doesn't support rdf:type properly.
1191 // In practise I have yet to see a file that
1192 // uses this element, however it is mentioned
1193 // on page 25 of part 1 of the xmp standard.
1195 // also it seems as if exiv2 and exiftool do not support
1196 // this either (That or I misunderstand the standard)
1197 $this->logger
->info( __METHOD__
. ' Encountered <rdf:type> which isn\'t currently supported' );
1200 if ( strpos( $elm, ' ' ) === false ) {
1201 // This probably shouldn't happen.
1202 $this->logger
->info( __METHOD__
. " Encountered <$elm> which has no namespace. Skipping." );
1207 list( $ns, $tag ) = explode( ' ', $elm, 2 );
1209 if ( count( $this->mode
) === 0 ) {
1210 // This should not happen.
1211 throw new RuntimeException( 'Error extracting XMP, '
1212 . "encountered <$elm> with no mode" );
1215 switch ( $this->mode
[0] ) {
1216 case self
::MODE_IGNORE
:
1217 $this->startElementModeIgnore( $elm );
1219 case self
::MODE_SIMPLE
:
1220 $this->startElementModeSimple( $elm, $attribs );
1222 case self
::MODE_INITIAL
:
1223 $this->startElementModeInitial( $ns, $tag, $attribs );
1225 case self
::MODE_STRUCT
:
1226 $this->startElementModeStruct( $ns, $tag, $attribs );
1228 case self
::MODE_BAG
:
1229 case self
::MODE_BAGSTRUCT
:
1230 $this->startElementModeBag( $elm );
1232 case self
::MODE_SEQ
:
1233 $this->startElementModeSeq( $elm );
1235 case self
::MODE_LANG
:
1236 $this->startElementModeLang( $elm );
1238 case self
::MODE_LI_LANG
:
1239 $this->startElementModeLiLang( $elm, $attribs );
1242 $this->startElementModeLi( $elm, $attribs );
1244 case self
::MODE_QDESC
:
1245 $this->startElementModeQDesc( $elm );
1248 throw new RuntimeException( 'StartElement in unknown mode: ' . $this->mode
[0] );
1253 * Process attributes.
1254 * Simple values can be stored as either a tag or attribute
1256 * Often the initial "<rdf:Description>" tag just has all the simple
1257 * properties as attributes.
1259 * @codingStandardsIgnoreStart Long line that cannot be broken
1262 * <rdf:Description rdf:about="" xmlns:exif="http://ns.adobe.com/exif/1.0/" exif:DigitalZoomRatio="0/10">
1264 * @codingStandardsIgnoreEnd
1266 * @param array $attribs Array attribute=>value
1267 * @throws RuntimeException
1269 private function doAttribs( $attribs ) {
1270 // first check for rdf:parseType attribute, as that can change
1271 // how the attributes are interperted.
1273 if ( isset( $attribs[self
::NS_RDF
. ' parseType'] )
1274 && $attribs[self
::NS_RDF
. ' parseType'] === 'Resource'
1275 && $this->mode
[0] === self
::MODE_SIMPLE
1277 // this is equivalent to having an inner rdf:Description
1278 $this->mode
[0] = self
::MODE_QDESC
;
1280 foreach ( $attribs as $name => $val ) {
1281 if ( strpos( $name, ' ' ) === false ) {
1282 // This shouldn't happen, but so far some old software forgets namespace
1284 $this->logger
->info( __METHOD__
. ' Encountered non-namespaced attribute: '
1285 . " $name=\"$val\". Skipping. " );
1288 list( $ns, $tag ) = explode( ' ', $name, 2 );
1289 if ( $ns === self
::NS_RDF
) {
1290 if ( $tag === 'value' ||
$tag === 'resource' ) {
1291 // resource is for url.
1292 // value attribute is a weird way of just putting the contents.
1293 $this->char( $this->xmlParser
, $val );
1295 } elseif ( isset( $this->items
[$ns][$tag] ) ) {
1296 if ( $this->mode
[0] === self
::MODE_SIMPLE
) {
1297 throw new RuntimeException( __METHOD__
1298 . " $ns:$tag found as attribute where not allowed" );
1300 $this->saveValue( $ns, $tag, $val );
1302 $this->logger
->debug( __METHOD__
. " Ignoring unrecognized element <$ns:$tag>." );
1308 * Given an extracted value, save it to results array
1310 * note also uses $this->ancestorStruct and
1311 * $this->processingArray to determine what name to
1312 * save the value under. (in addition to $tag).
1314 * @param string $ns Namespace of tag this is for
1315 * @param string $tag Tag name
1316 * @param string $val Value to save
1318 private function saveValue( $ns, $tag, $val ) {
1320 $info =& $this->items
[$ns][$tag];
1321 $finalName = isset( $info['map_name'] )
1322 ?
$info['map_name'] : $tag;
1323 if ( isset( $info['validate'] ) ) {
1324 if ( is_array( $info['validate'] ) ) {
1325 $validate = $info['validate'];
1327 $validator = new XMPValidate( $this->logger
);
1328 $validate = array( $validator, $info['validate'] );
1331 if ( is_callable( $validate ) ) {
1332 call_user_func_array( $validate, array( $info, &$val, true ) );
1333 // the reasoning behind using &$val instead of using the return value
1334 // is to be consistent between here and validating structures.
1335 if ( is_null( $val ) ) {
1336 $this->logger
->info( __METHOD__
. " <$ns:$tag> failed validation." );
1341 $this->logger
->warning( __METHOD__
. " Validation function for $finalName ("
1342 . $validate[0] . '::' . $validate[1] . '()) is not callable.' );
1346 if ( $this->ancestorStruct
&& $this->processingArray
) {
1347 // Aka both an array and a struct. ( self::MODE_BAGSTRUCT )
1348 $this->results
['xmp-' . $info['map_group']][$this->ancestorStruct
][][$finalName] = $val;
1349 } elseif ( $this->ancestorStruct
) {
1350 $this->results
['xmp-' . $info['map_group']][$this->ancestorStruct
][$finalName] = $val;
1351 } elseif ( $this->processingArray
) {
1352 if ( $this->itemLang
=== false ) {
1354 $this->results
['xmp-' . $info['map_group']][$finalName][] = $val;
1357 $this->results
['xmp-' . $info['map_group']][$finalName][$this->itemLang
] = $val;
1360 $this->results
['xmp-' . $info['map_group']][$finalName] = $val;