Xmp Delphi ActiveX Reference Documentation
TChilkatXmp
Current Version: 10.1.2
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.
Chilkat v9.5.*: If using Chilkat v9.5.*, then use "Chilkat_v9_5_0_TLB" instead of "Chilkat_TLB", and the DLLs are named ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll).
Two things are required to use an ActiveX in Delphi:
- 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.
- See also: ActiveX Registration Tutorial
- 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_TLB.pas and Chilkat_TLB.dcr. The Chilkat_TLB.pas should be added to your project.
To import the Chilkat type library, do the following:
- In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
- Find "Chilkat ActiveX" in the list and select it. This will only appear in the list if the ChilkatAx-win32.dll (or ChilkatAx-x64.dll) has been registered w/ regsvr32.
- Check the "Generate Component Wrappers" checkbox.
- Select a directory where the unit files (.pas and .dcr) should be generated.
- Select "Create Unit" and then "Finish".
- Add the .pas to your Delphi project.
To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_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_TLB;
Object Creation
var obj: TChilkatXmp; ... begin obj := TChilkatXmp.Create(Self); ... // When finished, free the object instance. obj.Free();
Properties
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.
LastBinaryResult
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.
topLastErrorHtml
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
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
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
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.
topLastStringResult
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.
LastStringResultLen
The length, in characters, of the string contained in the LastStringResult property.
topNumEmbedded
The number of XMP metadata documents found within the JPG or TIFF file loaded by LoadAppFile.
topStructInnerDescrip
Determines whether structures are stored with rdf:parseType="Resource", or within an "rdf:Description" sub-node.
topUncommonOptions
A property to be used for future uncommon needs. The default value is the empty string.
topVerboseLogging
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.
topVersion
Methods
AddArray
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".
AddNsMapping
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.
topAddSimpleInt
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".
topAddSimpleStr
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".
topAddStructProp
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".
topAppend
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.
topGetArray
Finds and returns an XMP array property. The property name should be prefixed with the namespace, such as "dc:subject".
Returns nil on failure
topGetEmbedded
Returns the Nth embedded XMP document as a Chilkat XML object.
Returns nil on failure
GetProperty
GetSimpleInt
Finds and returns an XMP integer property. The property name should be prefixed with the namespace, such as "tiff:ResolutionUnit".
topGetSimpleStr
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
GetStructPropNames
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
topGetStructValue
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
LoadAppFile
Loads a TIFF or JPG file into the XMP object.
topLoadFromBuffer
Loads a JPG or TIFF from an byte buffer containing the image file data.
topNewXmp
Creates and returns a new/empty XMP metadata document as a Chilkat XML object.
Returns nil on failure
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 1 for success, 0 for failure.
topRemoveArray
Removes an XMP array property from the XMP document.
topRemoveEmbedded
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.
topRemoveNsMapping
Removes a namespace-to-URI mapping.
topRemoveSimple
Removes a simple XMP property from the XMP document.
topRemoveStruct
Removes an XMP structure property from the XMP document.
topRemoveStructProp
Removes a single member from an XMP structured property.
topSaveAppFile
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.
topSaveToBuffer
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.