Xmp Classic ASP Reference Documentation

Xmp

Current Version: 11.6.0

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

set xmp = Server.CreateObject("Chilkat.Xmp")

' ... use xmp ...

set xmp = Nothing

Classic ASP creates Chilkat objects with Server.CreateObject. The registered Chilkat ActiveX must match the bitness of the IIS application pool: a pool with Enable 32-Bit Applications set to True needs the 32-bit ActiveX, otherwise the 64-bit ActiveX. To bind to a specific major version of Chilkat, append the major version number to the ProgID, such as Server.CreateObject("Chilkat.Xmp.11") for Chilkat v11.*.*.

VBScript requires set when assigning an object, so the signatures on this page show set x = obj.Method(...) for methods that return a Chilkat object; test the result with Is Nothing, since a method that fails to return an object returns Nothing. A method with no return value is called as a statement without parentheses (obj.Method arg1, arg2). Boolean properties, arguments and return values are integers in the ActiveX: pass 1 or 0, and test success with = 1. Byte arrays are Variant arrays and can be sent with Response.BinaryWrite. Asynchronous (*Async) methods and event callbacks are not used from Classic ASP.

Properties

DebugLogFilePath
xmp.DebugLogFilePath ' String

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.

More Information and Examples
top
LastBinaryResult
xmp.LastBinaryResult ' Variant (read-only)

This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. It is only accessible if Chilkat.Global.KeepBinaryResult is set to 1. This feature allows for the retrieval of large varbinary results in an SQL Server environment, which has restrictions on returning large data via method calls, though temp tables can handle binary properties.

top
LastErrorHtml
xmp.LastErrorHtml ' String (read-only)

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.

top
LastErrorText
xmp.LastErrorText ' String (read-only)

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.

top
LastErrorXml
xmp.LastErrorXml ' String (read-only)

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.

top
LastMethodSuccess
xmp.LastMethodSuccess ' Long

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.

top
LastStringResult
xmp.LastStringResult ' String (read-only)

In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. It is accessible only when Chilkat.Global.KeepStringResult is set to TRUE. SQL Server has limitations on string lengths returned from methods and properties, but temp tables can be used to access large strings.

top
LastStringResultLen
xmp.LastStringResultLen ' Long (read-only)

The length, in characters, of the string contained in the LastStringResult property.

top
NumEmbedded
xmp.NumEmbedded ' Long (read-only)

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

top
StructInnerDescrip
xmp.StructInnerDescrip ' Long

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

top
UncommonOptions
xmp.UncommonOptions ' String
Introduced in version 9.5.0.80

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

top
VerboseLogging
xmp.VerboseLogging ' Long

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.

top
Version
xmp.Version ' String (read-only)

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

More Information and Examples
top

Methods

AddArray
success = xmp.AddArray(xml, arrType, propName, values) ' Long (1/0)

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.

More Information and Examples
top
AddNsMapping
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.

top
AddSimpleInt
success = xmp.AddSimpleInt(iXml, propName, propVal) ' Long (1/0)

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.

top
AddSimpleStr
success = xmp.AddSimpleStr(iXml, propName, propVal) ' Long (1/0)

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.

top
AddStructProp
success = xmp.AddStructProp(iChilkatXml, structName, propName, propValue) ' Long (1/0)

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.

top
Append
success = xmp.Append(iXml) ' Long (1/0)

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.

top
GetArray
set stringArray = xmp.GetArray(iXml, propName) ' CkStringArray

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

Returns Nothing on failure

top
GetEmbedded
set xml = xmp.GetEmbedded(index) ' ChilkatXml

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

Returns Nothing on failure

More Information and Examples
top
GetProperty
set xml = xmp.GetProperty(iXml, propName) ' ChilkatXml

To be documented soon...

Returns Nothing on failure

top
GetSimpleInt
n = xmp.GetSimpleInt(iXml, propName) ' Long

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

top
GetSimpleStr
str = xmp.GetSimpleStr(iXml, propName) ' String

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

Returns Nothing on failure

More Information and Examples
top
GetStructPropNames
set stringArray = xmp.GetStructPropNames(iXml, structName) ' CkStringArray

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 Nothing on failure

top
GetStructValue
str = xmp.GetStructValue(iXml, structName, propName) ' String

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

Returns Nothing on failure

More Information and Examples
top
LoadAppFile
success = xmp.LoadAppFile(filename) ' Long (1/0)

Loads a TIFF or JPG file into the XMP object.

top
LoadFromBuffer
success = xmp.LoadFromBuffer(fileData, ext) ' Long (1/0)

Loads a JPG or TIFF from an byte buffer containing the image file data.

top
NewXmp
set xml = xmp.NewXmp() ' ChilkatXml

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

Returns Nothing on failure

More Information and Examples
top
RemoveAllEmbedded
success = xmp.RemoveAllEmbedded() ' Long (1/0)

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 1 for success, 0 for failure.

top
RemoveArray
success = xmp.RemoveArray(iXml, propName) ' Long (1/0)

Removes an XMP array property from the XMP document.

top
RemoveEmbedded
success = xmp.RemoveEmbedded(index) ' Long (1/0)

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

Returns 1 for success, 0 for failure.

top
RemoveNsMapping
xmp.RemoveNsMapping ns

Removes a namespace-to-URI mapping.

top
RemoveSimple
success = xmp.RemoveSimple(iXml, propName) ' Long (1/0)

Removes a simple XMP property from the XMP document.

top
RemoveStruct
success = xmp.RemoveStruct(iXml, structName) ' Long (1/0)

Removes an XMP structure property from the XMP document.

top
RemoveStructProp
success = xmp.RemoveStructProp(iXml, structName, propName) ' Long (1/0)

Removes a single member from an XMP structured property.

top
SaveAppFile
success = xmp.SaveAppFile(filename) ' Long (1/0)

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.

top
SaveToBuffer
bytes = xmp.SaveToBuffer() ' Variant

Saves a JPG or TIFF image with updated XMP to a byte buffer.

Returns a zero-length byte array (as a Variant) on failure.
An empty array will have a UBound of -1 meaning 0 elements.

top