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

Inheritance diagram for XMPReader:

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Collaboration diagram for XMPReader:

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Public Member Functions
	__construct (LoggerInterface $logger=null)
	Constructor. More...

	char ($parser, $data)
	Character data handler Called whenever character data is found in the xmp document. More...

	endElement ($parser, $elm)
	Handler for hitting a closing element. More...

	getResults ()
	Get the result array. More...

	parse ($content, $allOfIt=true)
	Main function to call to parse XMP. More...

	parseExtended ($content)
	Entry point for XMPExtended blocks in jpeg files. More...

	setLogger (LoggerInterface $logger)

	startElement ($parser, $elm, $attribs)
	Hits an opening element. More...

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

Public Attributes
const	MODE_ALT = 15

const	MODE_BAG = 13

const	MODE_BAGSTRUCT = 16

const	MODE_IGNORE = 1

const	MODE_INITIAL = 0
	These are various mode constants. More...

const	MODE_LANG = 14

const	MODE_LI = 2

const	MODE_LI_LANG = 3

const	MODE_QDESC = 4

const	MODE_SEQ = 12

const	MODE_SIMPLE = 10

const	MODE_STRUCT = 11

const	NS_RDF = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'

const	NS_XML = 'http://www.w3.org/XML/1998/namespace'

const	PARSABLE_BUFFERING = 2

const	PARSABLE_NO = 3

const	PARSABLE_OK = 1

const	PARSABLE_UNKNOWN = 0

Protected Attributes
array	$items
	XMP item configuration array. More...

Private Member Functions
	checkParseSafety ($content)
	Check if a block of XML is safe to pass to xml_parse, i.e. More...

	destroyXMLParser ()
	free the XML parser. More...

	doAttribs ($attribs)
	Process attributes. More...

	endElementModeIgnore ($elm)
	When we hit a closing element in MODE_IGNORE Check to see if this is the element we started to ignore, in which case we get out of MODE_IGNORE. More...

	endElementModeLi ($elm)
	Hit a closing element in MODE_LI (either rdf:Seq, or rdf:Bag ) Add information about what type of element this is. More...

	endElementModeQDesc ($elm)
	End element while in MODE_QDESC mostly when ending an element when we have a simple value that has qualifiers. More...

	endElementModeSimple ($elm)
	Hit a closing element when in MODE_SIMPLE. More...

	endElementNested ($elm)
	Hit a closing element in MODE_STRUCT, MODE_SEQ, MODE_BAG generally means we've finished processing a nested structure. More...

	resetXMLParser ()
	Main use is if a single item has multiple xmp documents describing it. More...

	saveValue ($ns, $tag, $val)
	Given an extracted value, save it to results array. More...

	startElementModeBag ($elm)
	Start element in MODE_BAG (unordered array) this should always be <rdf:Bag> More...

	startElementModeIgnore ($elm)
	Hit an opening element while in MODE_IGNORE. More...

	startElementModeInitial ($ns, $tag, $attribs)
	Starting an element when in MODE_INITIAL This usually happens when we hit an element inside the outer rdf:Description. More...

	startElementModeLang ($elm)
	Start element in MODE_LANG (language alternative) this should always be <rdf:Alt> More...

	startElementModeLi ($elm, $attribs)
	opening element in MODE_LI process elements of arrays. More...

	startElementModeLiLang ($elm, $attribs)
	Opening element in MODE_LI_LANG. More...

	startElementModeQDesc ($elm)
	Start an element when in MODE_QDESC. More...

	startElementModeSeq ($elm)
	Start element in MODE_SEQ (ordered array) this should always be <rdf:Seq> More...

	startElementModeSimple ($elm, $attribs)
	Handle an opening element when in MODE_SIMPLE. More...

	startElementModeStruct ($ns, $tag, $attribs)
	Hit an opening element when in a Struct (MODE_STRUCT) This is generally for fields of a compound property. More...

Private Attributes
bool string	$ancestorStruct = false
	The structure name when processing nested structures. More...

bool string	$charContent = false
	Temporary holder for character data that appears in xmp doc. More...

bool string	$charset = false
	Character set like 'UTF-8'. More...

array	$curItem = []
	Array to hold the current element (and previous element, and so on) More...

int	$extendedXMPOffset = 0

bool string	$itemLang = false
	Used for lang alts only. More...

LoggerInterface	$logger

array	$mode = []
	Stores the state the xmpreader is in (see MODE_FOO constants) More...

int	$parsable = 0
	Flag determining if the XMP is safe to parse. More...

bool	$processingArray = false
	If we're doing a seq or bag. More...

array	$results = []
	Array to hold results. More...

string	$xmlParsableBuffer = ''
	Buffer of XML to parse. More...

resource	$xmlParser
	A resource handle for the XML parser. More...

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.

Definition at line 54 of file XMP.php.

Constructor & Destructor Documentation

XMPReader::__construct ( LoggerInterface $logger = null )

Constructor.

Primary job is to initialize the XMLParser

Definition at line 138 of file XMP.php.

References XMPInfo\getItems(), resetXMLParser(), and setLogger().

Member Function Documentation

XMPReader::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

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

Exceptions

RuntimeException On invalid data

Definition at line 499 of file XMP.php.

Referenced by doAttribs().

XMPReader::checkParseSafety ( $content )

private

Check if a block of XML is safe to pass to xml_parse, i.e.

doesn't contain a doctype declaration which could contain a dos attack if we parse it and expand internal entities (T85848).

Parameters

string $content xml string to check for parse safety

Returns: bool true if the xml is safe to parse, false otherwise

Definition at line 536 of file XMP.php.

References $content.

Referenced by parse().

XMPReader::destroyXMLParser ( )

private

free the XML parser.

Note: It is unclear to me if we really need to do this ourselves or if php garbage collection will automatically free the xmlParser when it is no longer needed.

Definition at line 166 of file XMP.php.

Referenced by parse(), and resetXMLParser().

XMPReader::doAttribs ( $attribs )

private

Process attributes.

Simple values can be stored as either a tag or attribute

Often the initial "<rdf:Description>" tag just has all the simple properties as attributes.

Example:: <rdf:Description rdf:about="" xmlns:exif="http://ns.adobe.com/exif/1.0/" exif:DigitalZoomRatio="0/10">

Parameters

array $attribs Array attribute=>value

Exceptions

RuntimeException

Definition at line 1290 of file XMP.php.

References $attribs, $name, $tag, as, char(), list, and saveValue().

Referenced by startElementModeInitial(), startElementModeLi(), and startElementModeStruct().

XMPReader::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

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

Exceptions

RuntimeException

Definition at line 784 of file XMP.php.

References endElementModeIgnore(), endElementModeLi(), endElementModeQDesc(), endElementModeSimple(), and endElementNested().

XMPReader::endElementModeIgnore ( $elm )

private

When we hit a closing element in MODE_IGNORE Check to see if this is the element we started to ignore, in which case we get out of MODE_IGNORE.

Parameters

string $elm Namespace of element followed by a space and then tag name of element.

Definition at line 591 of file XMP.php.

Referenced by endElement().

XMPReader::endElementModeLi ( $elm )

private

Hit a closing element in MODE_LI (either rdf:Seq, or rdf:Bag ) Add information about what type of element this is.

Note we still have to hit the outer "</property>"

For example, when processing:: {,xml}

<exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>

</rdf:Seq> </exif:ISOSpeedRatings>

This method is called when we hit the "</rdf:Seq>". (For comparison, we call endElementModeSimple when we hit the "</rdf:li>")

Parameters

string $elm Namespace . ' ' . element name

Exceptions

RuntimeException

Definition at line 718 of file XMP.php.

References $tag, and list.

Referenced by endElement().

XMPReader::endElementModeQDesc ( $elm )

private

End element while in MODE_QDESC mostly when ending an element when we have a simple value that has qualifiers.

Qualifiers aren't all that common, and we don't do anything with them.

Parameters

string $elm Namespace and element

Definition at line 758 of file XMP.php.

References $tag, list, and saveValue().

Referenced by endElement().

XMPReader::endElementModeSimple ( $elm )

private

Hit a closing element when in MODE_SIMPLE.

This generally means that we finished processing a property value, and now have to save the result to the results array

For example, when processing: <exif:DigitalZoomRatio>0/10</exif:DigitalZoomRatio> this deals with when we hit </exif:DigitalZoomRatio>.

Or it could be if we hit the end element of a property of a compound data structure (like a member of an array).

Parameters

string $elm Namespace, space, and tag name.

Definition at line 613 of file XMP.php.

References $tag, list, and saveValue().

Referenced by endElement().

XMPReader::endElementNested ( $elm )

private

Hit a closing element in MODE_STRUCT, MODE_SEQ, MODE_BAG generally means we've finished processing a nested structure.

resets some internal variables to indicate that.

Note this means we hit the closing element not the "</rdf:Seq>".

For example, when processing:: {,xml}

<exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li>

</rdf:Seq> </exif:ISOSpeedRatings>

This method is called when we hit the "</exif:ISOSpeedRatings>" tag.

Parameters

string $elm Namespace . space . tag name.

Exceptions

RuntimeException

Definition at line 648 of file XMP.php.

References $tag, and list.

Referenced by endElement().

XMPReader::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().

Definition at line 208 of file XMP.php.

References $results, as, and list.

static XMPReader::isSupported ( )

static

Check if this instance supports using this class.

Definition at line 198 of file XMP.php.

Referenced by BitmapMetadataHandler\GIF(), BitmapMetadataHandler\Jpeg(), BitmapMetadataHandler\PNG(), and JpegMetadataExtractor\segmentSplitter().

XMPReader::parse	(	$content,
		$allOfIt = `true`
	)

Main function to call 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 its split up (false). Default true

Exceptions

RuntimeException

Returns: bool Success.

Definition at line 303 of file XMP.php.

References $code, $content, $e, $line, checkParseSafety(), destroyXMLParser(), and resetXMLParser().

Referenced by parseExtended(), and XMPTest\testXMPParse().

XMPReader::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.

Definition at line 419 of file XMP.php.

References $content, parse(), and resetXMLParser().

XMPReader::resetXMLParser ( )

private

Main use is if a single item has multiple xmp documents describing it.

For example in jpeg's with extendedXMP

Definition at line 177 of file XMP.php.

References destroyXMLParser().

Referenced by __construct(), parse(), and parseExtended().

XMPReader::saveValue	(	$ns,
		$tag,
		$val
	)

private

Given an extracted value, save it to results array.

note also uses $this->ancestorStruct and $this->processingArray to determine what name to save the value under. (in addition to $tag).

Parameters

string	$ns	Namespace of tag this is for
string	$tag	Tag name
string	$val	Value to save

Definition at line 1339 of file XMP.php.

References $ancestorStruct, $itemLang, and $tag.

Referenced by doAttribs(), endElementModeQDesc(), endElementModeSimple(), and startElementModeSimple().

XMPReader::setLogger ( LoggerInterface $logger )

Definition at line 155 of file XMP.php.

References $logger.

Referenced by __construct().

XMPReader::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

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

Exceptions

RuntimeException

Definition at line 1198 of file XMP.php.

References $attribs, $tag, list, startElementModeBag(), startElementModeIgnore(), startElementModeInitial(), startElementModeLang(), startElementModeLi(), startElementModeLiLang(), startElementModeQDesc(), startElementModeSeq(), startElementModeSimple(), and startElementModeStruct().

XMPReader::startElementModeBag ( $elm )

private

Start element in MODE_BAG (unordered array) this should always be <rdf:Bag>

Parameters

string $elm Namespace . ' ' . tag

Exceptions

RuntimeException If we have an element that's not <rdf:Bag>

Definition at line 880 of file XMP.php.

Referenced by startElement().

XMPReader::startElementModeIgnore ( $elm )

private

Hit an opening element while in MODE_IGNORE.

XMP is extensible, so ignore any tag we don't understand.

Mostly ignores, unless we encounter the element that we are ignoring. in which case we add it to the item stack, so we can ignore things that are nested, correctly.

Parameters

string $elm Namespace . ' ' . tag name

Definition at line 866 of file XMP.php.

Referenced by startElement().

XMPReader::startElementModeInitial	(	$ns,
		$tag,
		$attribs
	)

private

Starting an element when in MODE_INITIAL This usually happens when we hit an element inside the outer rdf:Description.

This is generally where most properties start.

Parameters

string	$ns	Namespace
string	$tag	Tag name (without namespace prefix)
array	$attribs	Array of attributes

Exceptions

RuntimeException

Definition at line 1007 of file XMP.php.

References $attribs, $tag, and doAttribs().

Referenced by startElement().

XMPReader::startElementModeLang ( $elm )

private

Start element in MODE_LANG (language alternative) this should always be <rdf:Alt>

This tag tends to be used for metadata like describe this picture, which can be translated into multiple languages.

XMP supports non-linguistic alternative selections, which are really only used for thumbnails, which we don't care about.

Parameters

string $elm Namespace . ' ' . tag

Exceptions

RuntimeException If we have an element that's not <rdf:Alt>

Definition at line 922 of file XMP.php.

Referenced by startElement().

XMPReader::startElementModeLi	(	$elm,
		$attribs
	)

private

opening element in MODE_LI process elements of arrays.

Example: <exif:ISOSpeedRatings> <rdf:Seq> <rdf:li>64</rdf:li> </rdf:Seq> </exif:ISOSpeedRatings> This method is called when we hit the <rdf:li> element.

Parameters

string	$elm	Namespace . ' ' . tagname
array	$attribs	Attributes. (needed for BAGSTRUCTS)

Exceptions

RuntimeException If gets a tag other than <rdf:li>

Definition at line 1117 of file XMP.php.

References $attribs, doAttribs(), and list.

Referenced by startElement().

XMPReader::startElementModeLiLang	(	$elm,
		$attribs
	)

private

Opening element in MODE_LI_LANG.

process elements of language alternatives

Example: <dc:title> <rdf:Alt> <rdf:li xml:lang="x-default">My house </rdf:li> </rdf:Alt> </dc:title>

This method is called when we hit the <rdf:li> element.

Parameters

string	$elm	Namespace . ' ' . tag
array	$attribs	Array of elements (most importantly xml:lang)

Exceptions

RuntimeException If gets a tag other than <rdf:li> or if no xml:lang

Definition at line 1167 of file XMP.php.

References $attribs.

Referenced by startElement().

XMPReader::startElementModeQDesc ( $elm )

private

Start an element when in MODE_QDESC.

This generally happens when a simple element has an inner rdf:Description to hold qualifier elements.

For example in: <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value> <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description> </exif:DigitalZoomRatio> Called when processing the <rdf:value> or <foo:someQualifier>.

Parameters

string $elm Namespace and tag name separated by a space.

Definition at line 985 of file XMP.php.

Referenced by startElement().

XMPReader::startElementModeSeq ( $elm )

private

Start element in MODE_SEQ (ordered array) this should always be <rdf:Seq>

Parameters

string $elm Namespace . ' ' . tag

Exceptions

RuntimeException If we have an element that's not <rdf:Seq>

Definition at line 895 of file XMP.php.

Referenced by startElement().

XMPReader::startElementModeSimple	(	$elm,
		$attribs
	)

private

Handle an opening element when in MODE_SIMPLE.

This should not happen often. This is for if a simple element already opened has a child element. Could happen for a qualified element.

For example: <exif:DigitalZoomRatio><rdf:Description><rdf:value>0/10</rdf:value> <foo:someQualifier>Bar</foo:someQualifier> </rdf:Description> </exif:DigitalZoomRatio>

This method is called when processing the <rdf:Description> element

Parameters

string	$elm	Namespace and tag names separated by space.
array	$attribs	Attributes of the element.

Exceptions

RuntimeException

Definition at line 948 of file XMP.php.

References $attribs, $tag, list, and saveValue().

Referenced by startElement().

XMPReader::startElementModeStruct	(	$ns,
		$tag,
		$attribs
	)

private

Hit an opening element when in a Struct (MODE_STRUCT) This is generally for fields of a compound property.

Example of a struct (abbreviated; flash has more properties):

<exif:Flash> <rdf:Description> <exif:Fired>True</exif:Fired> <exif:Mode>1</exif:Mode></rdf:Description></exif:Flash>

or:

<exif:Flash rdf:parseType='Resource'> <exif:Fired>True</exif:Fired> <exif:Mode>1</exif:Mode></exif:Flash>

Parameters

string	$ns	Namespace
string	$tag	Tag name (no ns)
array	$attribs	Array of attribs w/ values.

Exceptions

RuntimeException

Definition at line 1069 of file XMP.php.

References $attribs, $tag, and doAttribs().

Referenced by startElement().

Member Data Documentation

bool string XMPReader::$ancestorStruct = false

private

The structure name when processing nested structures.

Definition at line 62 of file XMP.php.

Referenced by saveValue().

bool string XMPReader::$charContent = false

private

Temporary holder for character data that appears in xmp doc.

Definition at line 65 of file XMP.php.

bool string XMPReader::$charset = false

private

Character set like 'UTF-8'.

Definition at line 83 of file XMP.php.

array XMPReader::$curItem = []

private

Array to hold the current element (and previous element, and so on)

Definition at line 59 of file XMP.php.

int XMPReader::$extendedXMPOffset = 0

private

Definition at line 86 of file XMP.php.

bool string XMPReader::$itemLang = false

private

Used for lang alts only.

Definition at line 77 of file XMP.php.

Referenced by saveValue().

array XMPReader::$items

protected

XMP item configuration array.

Definition at line 56 of file XMP.php.

LoggerInterface XMPReader::$logger

private

Definition at line 131 of file XMP.php.

Referenced by setLogger().

array XMPReader::$mode = []

private

Stores the state the xmpreader is in (see MODE_FOO constants)

Definition at line 68 of file XMP.php.

int XMPReader::$parsable = 0

private

Flag determining if the XMP is safe to parse.

Definition at line 89 of file XMP.php.

bool XMPReader::$processingArray = false

private

If we're doing a seq or bag.

Definition at line 74 of file XMP.php.

array XMPReader::$results = []

private

Array to hold results.

Definition at line 71 of file XMP.php.

Referenced by getResults().

string XMPReader::$xmlParsableBuffer = ''

private

Buffer of XML to parse.

Definition at line 92 of file XMP.php.

resource XMPReader::$xmlParser

private

A resource handle for the XML parser.

Definition at line 80 of file XMP.php.

const XMPReader::MODE_ALT = 15

Definition at line 116 of file XMP.php.

const XMPReader::MODE_BAG = 13

Definition at line 114 of file XMP.php.

const XMPReader::MODE_BAGSTRUCT = 16

Definition at line 117 of file XMP.php.

const XMPReader::MODE_IGNORE = 1

Definition at line 104 of file XMP.php.

const XMPReader::MODE_INITIAL = 0

These are various mode constants.

they are used to figure out what to do with an element when its encountered.

For example, MODE_IGNORE is used when processing a property we're not interested in. So if a new element pops up when we're in that mode, we ignore it.

Definition at line 103 of file XMP.php.

const XMPReader::MODE_LANG = 14

Definition at line 115 of file XMP.php.

const XMPReader::MODE_LI = 2

Definition at line 105 of file XMP.php.

const XMPReader::MODE_LI_LANG = 3

Definition at line 106 of file XMP.php.

const XMPReader::MODE_QDESC = 4

Definition at line 107 of file XMP.php.

const XMPReader::MODE_SEQ = 12

Definition at line 113 of file XMP.php.

const XMPReader::MODE_SIMPLE = 10

Definition at line 111 of file XMP.php.

const XMPReader::MODE_STRUCT = 11

Definition at line 112 of file XMP.php.

const XMPReader::NS_RDF = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'

Definition at line 119 of file XMP.php.

const XMPReader::NS_XML = 'http://www.w3.org/XML/1998/namespace'

Definition at line 120 of file XMP.php.

const XMPReader::PARSABLE_BUFFERING = 2

Definition at line 125 of file XMP.php.

const XMPReader::PARSABLE_NO = 3

Definition at line 126 of file XMP.php.

const XMPReader::PARSABLE_OK = 1

Definition at line 124 of file XMP.php.

const XMPReader::PARSABLE_UNKNOWN = 0

Definition at line 123 of file XMP.php.

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

includes/libs/xmp/XMP.php

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation