Xmp Chilkat2 Perl Reference Documentation
Chilkat2::Xmp
Current Version: 11.7.0
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Chilkat.Xmp
Load a
Retrieve embedded XMP documents as
Add or update namespace-qualified string and integer properties such as
Work with XMP arrays such as
Use built-in namespace mappings or add custom namespace-to-URI mappings
for application-specific XMP properties.
Remove properties, arrays, structures, or embedded XMP documents, then
persist changes to a file or return the updated image as a byte buffer.
Read, modify, add, remove, and save XMP metadata in JPG and TIFF files.
Chilkat.Xmp is a legacy class for working with embedded XMP
metadata in JPG and TIFF image files. It can load
image files or image data from memory, locate embedded XMP documents, return
XMP metadata as Chilkat.Xml, create new XMP documents, add or
update simple string and integer properties, manage arrays and structured
properties, add namespace mappings, remove selected XMP properties or entire
embedded XMP documents, and save the updated image back to a file or byte
buffer.
Chilkat.Xmp is maintained for existing JPG/TIFF XMP workflows,
but it is not planned to be extended to support additional file types.
Load JPG or TIFF metadata
JPG or TIFF file from disk or memory and
inspect how many embedded XMP documents were found.
Access XMP as XML
Chilkat.Xml objects for
inspection, editing, or direct XML-level processing.
Add simple properties
dc:subject, photoshop:Credit, or
tiff:XResolution.
Arrays and structures
bag, seq, and
alt, and manage structured property values.
Namespaces
Remove and save
LoadAppFile or
LoadFromBuffer, retrieve an embedded XMP document with
GetEmbedded or create one with NewXmp, modify it
using the add/remove property methods, then call SaveAppFile or
SaveToBuffer to persist the updated image metadata.
SaveAppFile is called. For memory workflows, use
SaveToBuffer to obtain the updated JPG or TIFF bytes.
Object Creation
use Chilkat2;
my $xmp = Chilkat2::Xmp->new;
# or set properties (and RaiseError) at creation:
# my $xmp = Chilkat2::Xmp->new(VerboseLogging => 1, RaiseError => 1);Creates the object. The optional pairs set writable properties (and RaiseError) in order, as if set one by one; an unknown or read-only name croaks. use Chilkat2; loads every class; the Chilkat2/Xmp.pm file holds only this class's documentation (perldoc Chilkat2::Xmp).
Perl frees the object when its last reference goes (undef $xmp, or the variable going out of scope); there is nothing to close. Objects returned by methods are independent and freed the same way. The class may be subclassed (use parent -norequire, 'Chilkat2::Xmp';): an object is a blessed hash reference whose hash is free for the subclass's own fields.
When false (the default), a method that fails returns false (or undef), and the reason is in LastErrorText. When true, it dies with a Chilkat2::Error instead, as DBI does with its RaiseError. Objects returned by a method inherit the value of the object that returned them.
Errors
A Chilkat2::Error stringifies to the failed call's full LastErrorText, and has the methods text, class ('Chilkat2::Xmp'), method (the method name) and object. Methods that look something up and find nothing return undef without dying (each such method says so), methods that answer a question (HasMember, IsUnlocked, ...) return a plain boolean, and property reads and writes never fail for Chilkat reasons.
Misuse always croaks, with your file and line, whatever RaiseError is: a wrong number of arguments, a reference or undef where a string or number is expected, an object of the wrong class, an out-of-range integer, a string containing a NUL character, a wide character in a byte string, or a write to a read-only property.
Strings are Perl character strings in both directions (length, regexes and :encoding layers see characters); binary data (BinData) is a byte string. Unlocking: call Chilkat2::Global->new->UnlockBundle('...') once at startup.
Properties
DebugLogFilePath
my $strVal = $xmp->DebugLogFilePath;
$xmp->DebugLogFilePath($strVal);
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
LastErrorHtml
my $strVal = $xmp->LastErrorHtml;
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
my $strVal = $xmp->LastErrorText;
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
my $strVal = $xmp->LastErrorXml;
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
my $boolVal = $xmp->LastMethodSuccess;
$xmp->LastMethodSuccess($boolVal);
Indicates the success or failure of the most recent method call: 1 means success, 0 means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
NumEmbedded
my $intVal = $xmp->NumEmbedded;
The number of XMP metadata documents found within the JPG or TIFF file loaded by LoadAppFile.
topStructInnerDescrip
my $boolVal = $xmp->StructInnerDescrip;
$xmp->StructInnerDescrip($boolVal);
Determines whether structures are stored with rdf:parseType=Resource, or within an rdf:Description sub-node.
UncommonOptions
my $strVal = $xmp->UncommonOptions;
$xmp->UncommonOptions($strVal);
A property to be used for future uncommon needs. The default value is the empty string.
topVerboseLogging
my $boolVal = $xmp->VerboseLogging;
$xmp->VerboseLogging($boolVal);
If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
my $strVal = $xmp->Version;
Methods
AddArray
# $arrType is a string
# $propName is a string
# $values is a Chilkat2::StringArray
# $success is true or false
my $success = $xmp->AddArray($xml, $arrType, $propName, $values);
Adds or replaces an XMP property array. The XMP metadata to be updated is contained in the XML object passed in the 1st argument. The 2nd argument specifies the array type, which can be bag, seq, or alt. The property name should be prefixed with the namespace, such as dc:subject.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
AddNsMapping
# $uri is a string
$xmp->AddNsMapping($ns, $uri);
Adds a namespace to URI mapping. When a property is added via AddSimpleString or any of the other methods, the property name is namespace qualified. When adding the first property in a namespace, the rdf:Description is automatically added and the URI is obtained from the namespace-to-URI mappings. The standard (and commonly used) namespace mappings are defined by default. This is only used if the namespace is custom or not already handled.
Returns the object, so calls can be chained.
topAddSimpleInt
# $propName is a string
# $propVal is an integer
# $success is true or false
my $success = $xmp->AddSimpleInt($iXml, $propName, $propVal);
Adds or updates an XMP integer property. The XMP metadata to be updated is contained in the XML object passed in the 1st argument. The property name should be prefixed with the namespace, such as tiff:XResolution.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
AddSimpleStr
# $propName is a string
# $propVal is a string
# $success is true or false
my $success = $xmp->AddSimpleStr($iXml, $propName, $propVal);
Adds or updates a simple XMP string property. The XMP metadata to be updated is contained in the XML object passed in the 1st argument. The property name should be prefixed with the namespace, such as photoshop:Credit.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
AddStructProp
# $structName is a string
# $propName is a string
# $propValue is a string
# $success is true or false
my $success = $xmp->AddStructProp($iChilkatXml, $structName, $propName, $propValue);
Adds or updates an XMP structured property value. The XMP metadata to be updated is contained in the XML object passed in the 1st argument. The structure name should be prefixed with the namespace, such as Iptc4xmpCore:CreatorContactInfo. The property name within the structure should also be prefixed with the namespace, such as Iptc4xmpCore:CiAdrCity.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
Append
Appends a new XMP metadata file to the XMP object. Any XMPs appended via this method will be present in the file when SaveAppFile is called. Files containing XMP metadata typically only include a single XMP document, so this method is usually only called when adding XMP metadata to a file for the first time.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
GetArray
# $propName is a string
# $stringArray is a Chilkat2::StringArray or undef
my $stringArray = $xmp->GetArray($iXml, $propName);
Finds and returns an XMP array property. The property name should be prefixed with the namespace, such as dc:subject.
Returns undef if not found: this is not an error, and it never dies, whatever RaiseError is. The returned object is new and independent of this one, and inherits its RaiseError.
GetEmbedded
Returns the Nth embedded XMP document as a Chilkat XML object.
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way. The returned object is new and independent of this one, and inherits its RaiseError.
GetProperty
# $propName is a string
# $xml is a Chilkat2::Xml or undef
my $xml = $xmp->GetProperty($iXml, $propName);
To be documented soon...
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way. The returned object is new and independent of this one, and inherits its RaiseError.
GetSimpleInt
# $propName is a string
# $n is an integer
my $n = $xmp->GetSimpleInt($iXml, $propName);
Finds and returns an XMP integer property. The property name should be prefixed with the namespace, such as tiff:ResolutionUnit.
GetSimpleStr
# $propName is a string
# $str is a string or undef
my $str = $xmp->GetSimpleStr($iXml, $propName);
Finds and returns an XMP simple string property. The property name should be prefixed with the namespace, such as photoshop:Source.
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
GetStructPropNames
# $structName is a string
# $stringArray is a Chilkat2::StringArray or undef
my $stringArray = $xmp->GetStructPropNames($iXml, $structName);
Returns the property names used by an exsting structure within an XMP document. The contents of the structure can be retrieved by calling GetStructValue for each property name returned by GetStructPropNames.
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way. The returned object is new and independent of this one, and inherits its RaiseError.
GetStructValue
# $structName is a string
# $propName is a string
# $str is a string or undef
my $str = $xmp->GetStructValue($iXml, $structName, $propName);
Returns the value of a single item within an XMP structure property. Property names should always be prefixed with the namespace.
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
LoadAppFile
# $success is true or false
my $success = $xmp->LoadAppFile($filename);
Loads a TIFF or JPG file into the XMP object.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
NewXmp
Creates and returns a new/empty XMP metadata document as a Chilkat XML object.
Returns undef on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way. The returned object is new and independent of this one, and inherits its RaiseError.
RemoveAllEmbedded
my $success = $xmp->RemoveAllEmbedded();
Removes all XMP metadata documents from an XMP object. After calling this method, call SaveAppFile to rewrite the JPG or TIFF file with the XMP metadata removed.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
RemoveArray
# $propName is a string
# $success is true or false
my $success = $xmp->RemoveArray($iXml, $propName);
Removes an XMP array property from the XMP document.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
RemoveEmbedded
# $success is true or false
my $success = $xmp->RemoveEmbedded($index);
Removes a single XMP metadata document from the JPG or TIFF file. Call SaveAppFile to persist the changes to disk.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
RemoveNsMapping
$xmp->RemoveNsMapping($ns);
RemoveSimple
# $propName is a string
# $success is true or false
my $success = $xmp->RemoveSimple($iXml, $propName);
Removes a simple XMP property from the XMP document.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
RemoveStruct
# $structName is a string
# $success is true or false
my $success = $xmp->RemoveStruct($iXml, $structName);
Removes an XMP structure property from the XMP document.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
RemoveStructProp
# $structName is a string
# $propName is a string
# $success is true or false
my $success = $xmp->RemoveStructProp($iXml, $structName, $propName);
Removes a single member from an XMP structured property.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.
SaveAppFile
# $success is true or false
my $success = $xmp->SaveAppFile($filename);
Persists all changes made to the XMP document(s) by saving the XMP object to a file. Changes made by adding, updating, or removing properties are not persisted to the filesystem until this is called.
Returns true on success, false on failure; LastErrorText says why. With RaiseError on, a failure dies with a Chilkat2::Error instead (it stringifies to the LastErrorText); the object remains usable either way.