Xmp Chilkat2 PHP Reference Documentation

Xmp

Current Version: 11.7.0

Markdown version of this page for AI tools (v 11.7.0) · all AI docs

Chilkat.Xmp

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.

Legacy class: 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

Load a JPG or TIFF file from disk or memory and inspect how many embedded XMP documents were found.

Access XMP as XML

Retrieve embedded XMP documents as Chilkat.Xml objects for inspection, editing, or direct XML-level processing.

Add simple properties

Add or update namespace-qualified string and integer properties such as dc:subject, photoshop:Credit, or tiff:XResolution.

Arrays and structures

Work with XMP arrays such as bag, seq, and alt, and manage structured property values.

Namespaces

Use built-in namespace mappings or add custom namespace-to-URI mappings for application-specific XMP properties.

Remove and save

Remove properties, arrays, structures, or embedded XMP documents, then persist changes to a file or return the updated image as a byte buffer.

Common pattern: Load a JPG or TIFF with 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.
Persistence note: Changes made to the XMP XML object are not written back to the image file until SaveAppFile is called. For memory workflows, use SaveToBuffer to obtain the updated JPG or TIFF bytes.

Object Creation

use Chilkat2\Xmp;

try {
    $xmp = new Xmp();
    // ... use $xmp ...
} catch (\Chilkat2\Exception $e) {
    echo $e->getClass(), '::', $e->getMethod(), " failed\n";
    echo $e->getMessage(), "\n";              // the LastErrorText of the failed call
}
public function __construct(array $properties = [])

Creates the object. The optional array sets properties in order, as if assigned one by one (new Xmp(['VerboseLogging' => true, 'RaiseError' => false])); an unknown or read-only name throws Error. The class is defined by the chilkat2 extension (extension=chilkat2 in php.ini): there is no PHP file to include.

There is no close(): PHP frees the object when its last reference goes (unset($xmp), $xmp = null, or the end of the function or request). Objects returned by methods are independent and freed the same way. The class may be extended (class MyXmp extends \Chilkat2\Xmp); objects cannot be cloned or serialized.

public bool $RaiseError;

When true (the default), a method that fails throws Chilkat2\Exception. When false, it returns false (or null) instead, and the reason is in LastErrorText. Objects returned by a method inherit the value of the object that returned them.

Errors

Chilkat2\Exception extends RuntimeException: getMessage() is the failed call's full LastErrorText, getClass() its class ('Chilkat2\Xmp') and getMethod() the method name. The object remains usable. Methods that look something up and find nothing return null without throwing (each such method says so), methods that answer a question (HasMember, IsUnlocked, ...) return a plain bool, and property reads and writes do not throw for Chilkat reasons.

Misuse always throws, whatever RaiseError is: a wrong argument type is a TypeError (exact types under declare(strict_types=1)), a missing or extra argument an ArgumentCountError, a string containing a NUL byte or an out-of-range integer a ValueError, and an unknown property (properties are case-sensitive) or a write to a read-only one an Error. Named arguments work with the parameter names shown.

Strings are passed and returned as UTF-8; binary data is a PHP string of bytes. Unlocking: call (new \Chilkat2\GlobalSettings())->UnlockBundle('...') once at startup.

Properties

DebugLogFilePath
public string $DebugLogFilePath;

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.

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LastErrorHtml
public readonly string $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.

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LastErrorText
public readonly string $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.

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LastErrorXml
public readonly string $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.

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LastMethodSuccess
public bool $LastMethodSuccess;

Indicates the success or failure of the most recent method call: true means success, false 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.

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NumEmbedded
public readonly int $NumEmbedded;

The number of XMP metadata documents found within the JPG or TIFF file loaded by LoadAppFile.

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StructInnerDescrip
public bool $StructInnerDescrip;

Determines whether structures are stored with rdf:parseType=Resource, or within an rdf:Description sub-node.

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UncommonOptions
public string $UncommonOptions;
Introduced in version 9.5.0.80

A property to be used for future uncommon needs. The default value is the empty string.

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VerboseLogging
public bool $VerboseLogging;

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
public readonly string $Version;

Version of the component/library, such as "10.1.0"

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Methods

AddArray
public function AddArray(Xml $xml, string $arrType, string $propName, StringArray $values): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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AddNsMapping
public function AddNsMapping(string $ns, string $uri): void

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.

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AddSimpleInt
public function AddSimpleInt(Xml $iXml, string $propName, int $propVal): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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AddSimpleStr
public function AddSimpleStr(Xml $iXml, string $propName, string $propVal): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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AddStructProp
public function AddStructProp(Xml $iChilkatXml, string $structName, string $propName, string $propValue): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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Append
public function Append(Xml $iXml): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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GetArray
public function GetArray(Xml $iXml, string $propName): ?StringArray

Finds and returns an XMP array property. The property name should be prefixed with the namespace, such as dc:subject.

Returns null if not found: this is not an error, and it does not throw whatever RaiseError is. The returned object is new and independent of this one, and inherits its RaiseError.

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GetEmbedded
public function GetEmbedded(int $index): ?Xml

Returns the Nth embedded XMP document as a Chilkat XML object.

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable. The returned object is new and independent of this one, and inherits its RaiseError.

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GetProperty
public function GetProperty(Xml $iXml, string $propName): ?Xml

To be documented soon...

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable. The returned object is new and independent of this one, and inherits its RaiseError.

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GetSimpleInt
public function GetSimpleInt(Xml $iXml, string $propName): int

Finds and returns an XMP integer property. The property name should be prefixed with the namespace, such as tiff:ResolutionUnit.

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GetSimpleStr
public function GetSimpleStr(Xml $iXml, string $propName): ?string

Finds and returns an XMP simple string property. The property name should be prefixed with the namespace, such as photoshop:Source.

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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GetStructPropNames
public function GetStructPropNames(Xml $iXml, string $structName): ?StringArray

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.

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable. The returned object is new and independent of this one, and inherits its RaiseError.

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GetStructValue
public function GetStructValue(Xml $iXml, string $structName, string $propName): ?string

Returns the value of a single item within an XMP structure property. Property names should always be prefixed with the namespace.

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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LoadAppFile
public function LoadAppFile(string $filename): bool

Loads a TIFF or JPG file into the XMP object.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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NewXmp
public function NewXmp(): ?Xml

Creates and returns a new/empty XMP metadata document as a Chilkat XML object.

On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns null). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable. The returned object is new and independent of this one, and inherits its RaiseError.

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RemoveAllEmbedded
public function RemoveAllEmbedded(): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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RemoveArray
public function RemoveArray(Xml $iXml, string $propName): bool

Removes an XMP array property from the XMP document.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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RemoveEmbedded
public function RemoveEmbedded(int $index): bool

Removes a single XMP metadata document from the JPG or TIFF file. Call SaveAppFile to persist the changes to disk.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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RemoveNsMapping
public function RemoveNsMapping(string $ns): void

Removes a namespace-to-URI mapping.

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RemoveSimple
public function RemoveSimple(Xml $iXml, string $propName): bool

Removes a simple XMP property from the XMP document.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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RemoveStruct
public function RemoveStruct(Xml $iXml, string $structName): bool

Removes an XMP structure property from the XMP document.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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RemoveStructProp
public function RemoveStructProp(Xml $iXml, string $structName, string $propName): bool

Removes a single member from an XMP structured property.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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SaveAppFile
public function SaveAppFile(string $filename): bool

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. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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