Wikimedia\XMPReader\Reader Class Reference

Class for reading xmp data containing properties relevant to images, and spitting out an array that FormatMetadata accepts. More...

Inheritance diagram for Wikimedia\XMPReader\Reader:

Collaboration diagram for Wikimedia\XMPReader\Reader:

Public Member Functions
	__construct (LoggerInterface $logger=null, $filename='unknown')
	Primary job is to initialize the XMLParser.
	getResults ()
	Get the result array.
	parse ( $content, $allOfIt=true)
	Main function to parse XMP.
	parseExtended ( $content)
	Entry point for XMPExtended blocks in jpeg files.
	char ( $parser, $data)
	Character data handler Called whenever character data is found in the xmp document.
	endElement ( $parser, $elm)
	Handler for hitting a closing element.
	startElement ( $parser, $elm, $attribs)
	Hits an opening element.

Static Public Member Functions
static	isSupported ()
	Check if this instance supports using this class.

Public Attributes
const	MODE_SIMPLE = 10
const	MODE_STRUCT = 11
const	MODE_SEQ = 12
const	MODE_BAG = 13
const	MODE_LANG = 14
const	MODE_ALT = 15
const	MODE_BAGSTRUCT = 16

Protected Attributes
array	$items

Detailed Description

Class for reading xmp data containing properties relevant to images, and spitting out an array that FormatMetadata accepts.

Note, this is not meant to recognize every possible thing you can encode in XMP. It should recognize all the properties we want. For example, it doesn't have support for structures with multiple nesting levels, as none of the properties we're supporting use that feature. If it comes across properties it doesn't recognize, it should ignore them.

The public methods one would call in this class are

• parse( $content ) Reads in xmp content. Can potentially be called multiple times with partial data each time.
• parseExtended( $content ) Reads XMPExtended blocks (jpeg files only).
• getResults Outputs a results array.

Note XMP kind of looks like rdf. They are not the same thing - XMP is encoded as a specific subset of rdf. This class can read XMP. It cannot read rdf.

Constructor & Destructor Documentation

__construct()

Wikimedia\XMPReader\Reader::__construct	(	LoggerInterface	$logger = null,
			$filename = 'unknown' )

Primary job is to initialize the XMLParser.

Parameters

LoggerInterface | null	$logger	Logger instance if available
string	$filename

Member Function Documentation

char()

Wikimedia\XMPReader\Reader::char	(		$parser,
			$data )

Character data handler Called whenever character data is found in the xmp document.

does nothing if we're in MODE_IGNORE or if the data is whitespace throws an error if we're not in MODE_SIMPLE (as we're not allowed to have character data in the other modes).

As an example, this happens when we encounter XMP like: <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio> and are processing the 0/10 bit.

Parameters

resource	$parser	XMLParser reference to the xml parser
string	$data	Character data

Exceptions

RuntimeException

On invalid data

endElement()

Wikimedia\XMPReader\Reader::endElement	(		$parser,
			$elm )

Handler for hitting a closing element.

generally just calls a helper function depending on what mode we're in.

Ignores the outer wrapping elements that are optional in xmp and have no meaning.

Parameters

resource	$parser
string	$elm	Namespace . ' ' . element name

Exceptions

RuntimeException

getResults()

Wikimedia\XMPReader\Reader::getResults

(

)

Get the result array.

Do some post-processing before returning the array, and transform any metadata that is special-cased.

Returns

array Array of results as an array of arrays suitable for FormatMetadata::getFormattedData().

isSupported()

static Wikimedia\XMPReader\Reader::isSupported ( )

static

Check if this instance supports using this class.

Returns

bool

parse()

string Buffer of XML to Wikimedia\XMPReader\Reader::parse	(		$content,
			$allOfIt = true )

Main function to parse XMP.

Use getResults to get results.

Also catches any errors during processing, writes them to debug log, blanks result array and returns false.

Parameters

string	$content	XMP data
bool	$allOfIt	If this is all the data (true), or if it's split up (false). Default true

Exceptions

RuntimeException

Returns

bool Success.

parseExtended()

Wikimedia\XMPReader\Reader::parseExtended

(

$content

)

Entry point for XMPExtended blocks in jpeg files.

Todo

In serious need of testing

See also

http://www.adobe.ge/devnet/xmp/pdfs/XMPSpecificationPart3.pdf XMP spec part 3 page 20

Parameters

string

$content

XMPExtended block minus the namespace signature

Returns

bool If it succeeded.

startElement()

Wikimedia\XMPReader\Reader::startElement	(		$parser,
			$elm,
			$attribs )

Hits an opening element.

Generally just calls a helper based on what MODE we're in. Also does some initial set up for the wrapper element

Parameters

resource	$parser
string	$elm	Namespace "<space>" element
array	$attribs	Attribute name => value

Exceptions

RuntimeException

---

The documentation for this class was generated from the following file:

• src/Reader.php