TChilkatXmp Delphi ActiveX Reference Documentation

TChilkatXmp

Current Version: 9.5.0.73

Chilkat XMP is a software component (SDK, toolkit, library, etc) for accessing, manipulating, and adding XMP metadata to JPEG and TIFF files.

Importing the Chilkat ActiveX into Delphi

Important: When upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.

Two things are required to use an ActiveX in Delphi:

  1. The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
  2. See also: ActiveX Registration Tutorial
  3. The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_v9_5_0_TLB.pas and Chilkat_v9_5_0_TLB.dcr. The Chilkat_v9_5_0_TLB.pas should be added to your project.

To import the Chilkat type library, do the following:

  1. In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
  2. Find "Chilkat ActiveX v9.5.0" in the list and select it. This will only appear in the list if the ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll) has been registered w/ regsvr32.
  3. Check the "Generate Component Wrappers" checkbox.
  4. Select a directory where the unit files (.pas and .dcr) should be generated.
  5. Select "Create Unit" and then "Finish".
  6. Add the .pas to your Delphi project.

To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_v9_5_0_TLB" to the "uses" statement. For example:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_v9_5_0_TLB;

Object Creation

var
obj: TChilkatXmp;
...
begin
obj := TChilkatXmp.Create(Self);
...
// When finished, free the object instance.
obj.Free();

Properties

DebugLogFilePath
property DebugLogFilePath: WideString

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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LastBinaryResult
property LastBinaryResult: OleVariant readonly
Introduced in version 9.5.0.52

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to 1. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).

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LastErrorHtml
property LastErrorHtml: WideString readonly

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
property LastErrorText: WideString readonly

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
property LastErrorXml: WideString readonly

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
property LastMethodSuccess: Integer
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = 1 and failure = 0.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastStringResult
property LastStringResult: WideString readonly
Introduced in version 9.5.0.52

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to 1. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).

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LastStringResultLen
property LastStringResultLen: Integer readonly
Introduced in version 9.5.0.53

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

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NumEmbedded
property NumEmbedded: Integer readonly

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

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StructInnerDescrip
property StructInnerDescrip: Integer

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

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VerboseLogging
property VerboseLogging: Integer

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.

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Version
property Version: WideString readonly

Version of the component/library, such as "9.5.0.63"

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Methods

AddArray
function AddArray(xml: TChilkatXml; arrType: WideString; propName: WideString; values: TCkStringArray): Integer;

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
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AddNsMapping
procedure AddNsMapping(ns: WideString; uri: WideString);

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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AddSimpleDate
function AddSimpleDate(iXml: TChilkatXml; propName: WideString; propVal: TDateTime): Integer;
This method is deprecated. It will be removed in a future version.

Adds or replaces an XMP date 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 "xap:CreateDate".

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AddSimpleInt
function AddSimpleInt(iXml: TChilkatXml; propName: WideString; propVal: Integer): Integer;

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".

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AddSimpleStr
function AddSimpleStr(iXml: TChilkatXml; propName: WideString; propVal: WideString): Integer;

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".

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AddStructProp
function AddStructProp(iChilkatXml: TChilkatXml; structName: WideString; propName: WideString; propValue: WideString): Integer;

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".

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Append
function Append(iXml: TChilkatXml): Integer;

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.

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DateToString
function DateToString(d: TDateTime): WideString;
This method is deprecated. It will be removed in a future version.

Converts a date to a string representation. This method is added for convenience (just in case date-to-string conversions are required).

Returns a zero-length WideString on failure

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GetArray
function GetArray(iXml: TChilkatXml; propName: WideString): TCkStringArray;

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

Returns nil on failure

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GetEmbedded
function GetEmbedded(index: Integer): TChilkatXml;

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

Returns nil on failure

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GetProperty
function GetProperty(iXml: TChilkatXml; propName: WideString): TChilkatXml;

To be documented soon...

Returns nil on failure

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GetSimpleDate
function GetSimpleDate(iXml: TChilkatXml; propName: WideString): TDateTime;
This method is deprecated. It will be removed in a future version.

Finds and returns an XMP date property. The property name should be prefixed with the namespace, such as "xap:ModifyDate".

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GetSimpleInt
function GetSimpleInt(iXml: TChilkatXml; propName: WideString): Integer;

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
function GetSimpleStr(iXml: TChilkatXml; propName: WideString): WideString;

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

Returns a zero-length WideString on failure

More Information and Examples
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GetStructPropNames
function GetStructPropNames(iXml: TChilkatXml; structName: WideString): TCkStringArray;

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 nil on failure

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GetStructValue
function GetStructValue(iXml: TChilkatXml; structName: WideString; propName: WideString): WideString;

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

Returns a zero-length WideString on failure

More Information and Examples
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LoadAppFile
function LoadAppFile(filename: WideString): Integer;

Loads a TIFF or JPG file into the XMP object.

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LoadFromBuffer
function LoadFromBuffer(fileData: OleVariant; ext: WideString): Integer;

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

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NewXmp
function NewXmp(): TChilkatXml;

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

Returns nil on failure

More Information and Examples
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RemoveAllEmbedded
function RemoveAllEmbedded(): Integer;

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.

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RemoveArray
function RemoveArray(iXml: TChilkatXml; propName: WideString): Integer;

Removes an XMP array property from the XMP document.

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RemoveEmbedded
function RemoveEmbedded(index: Integer): Integer;

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.

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RemoveNsMapping
procedure RemoveNsMapping(ns: WideString);

Removes a namespace-to-URI mapping.

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RemoveSimple
function RemoveSimple(iXml: TChilkatXml; propName: WideString): Integer;

Removes a simple XMP property from the XMP document.

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RemoveStruct
function RemoveStruct(iXml: TChilkatXml; structName: WideString): Integer;

Removes an XMP structure property from the XMP document.

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RemoveStructProp
function RemoveStructProp(iXml: TChilkatXml; structName: WideString; propName: WideString): Integer;

Removes a single member from an XMP structured property.

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SaveAppFile
function SaveAppFile(filename: WideString): Integer;

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.

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SaveToBuffer
function SaveToBuffer(): OleVariant;

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

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

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StringToDate
function StringToDate(str: WideString): TDateTime;
This method is deprecated. It will be removed in a future version.

Converts a string to a date value. This method is added for convenience (just in case string-to-date conversions are required).

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UnlockComponent
function UnlockComponent(unlockCode: WideString): Integer;

Unlocks the XMP component at runtime. This must be called once at the beginning of your application. Passing an arbitrary value initiates a fully-functional 30-day trial. A purchased unlock code is required to use the component beyond 30 days.

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