Xmp Unicode C Reference Documentation

Xmp

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.

Create/Dispose

HCkXmpW instance = CkXmpW_Create();
// ...
CkXmpW_Dispose(instance);
HCkXmpW CkXmpW_Create(void);

Creates an instance of the HCkXmpW object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkXmpW_Dispose(HCkXmpW handle);

Objects created by calling CkXmpW_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkXmpW_Dispose.

Properties

DebugLogFilePath
void CkXmpW_getDebugLogFilePath(HCkXmpW cHandle, HCkString retval);
void CkXmpW_putDebugLogFilePath(HCkXmpW cHandle, const wchar_t *newVal);
const wchar_t *CkXmpW_debugLogFilePath(HCkXmpW cHandle);

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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LastErrorHtml
void CkXmpW_getLastErrorHtml(HCkXmpW cHandle, HCkString retval);
const wchar_t *CkXmpW_lastErrorHtml(HCkXmpW cHandle);

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
void CkXmpW_getLastErrorText(HCkXmpW cHandle, HCkString retval);
const wchar_t *CkXmpW_lastErrorText(HCkXmpW cHandle);

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
void CkXmpW_getLastErrorXml(HCkXmpW cHandle, HCkString retval);
const wchar_t *CkXmpW_lastErrorXml(HCkXmpW cHandle);

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
BOOL CkXmpW_getLastMethodSuccess(HCkXmpW cHandle);
void CkXmpW_putLastMethodSuccess(HCkXmpW cHandle, BOOL newVal);
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of TRUE indicates success, a value of FALSE 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 = TRUE and failure = FALSE.
  • 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 TRUE. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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NumEmbedded
int CkXmpW_getNumEmbedded(HCkXmpW cHandle);

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

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StructInnerDescrip
BOOL CkXmpW_getStructInnerDescrip(HCkXmpW cHandle);
void CkXmpW_putStructInnerDescrip(HCkXmpW cHandle, BOOL newVal);

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

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VerboseLogging
BOOL CkXmpW_getVerboseLogging(HCkXmpW cHandle);
void CkXmpW_putVerboseLogging(HCkXmpW cHandle, BOOL newVal);

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
void CkXmpW_getVersion(HCkXmpW cHandle, HCkString retval);
const wchar_t *CkXmpW_version(HCkXmpW cHandle);

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

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Methods

AddArray
BOOL CkXmpW_AddArray(HCkXmpW cHandle, HCkXmlW xml, const wchar_t *arrType, const wchar_t *propName, HCkStringArrayW 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".

More Information and Examples
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AddNsMapping
void CkXmpW_AddNsMapping(HCkXmpW cHandle, const wchar_t *ns, const wchar_t *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.

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AddSimpleDate
BOOL CkXmpW_AddSimpleDate(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName, SYSTEMTIME * propVal);
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
BOOL CkXmpW_AddSimpleInt(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName, int 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".

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AddSimpleStr
BOOL CkXmpW_AddSimpleStr(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName, const wchar_t *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".

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AddStructProp
BOOL CkXmpW_AddStructProp(HCkXmpW cHandle, HCkXmlW iChilkatXml, const wchar_t *structName, const wchar_t *propName, const wchar_t *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".

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Append
BOOL CkXmpW_Append(HCkXmpW cHandle, HCkXmlW iXml);

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
BOOL CkXmpW_DateToString(HCkXmpW cHandle, SYSTEMTIME * d, const wchar_t *outStr);
const wchar_t *CkXmpW_dateToString(HCkXmpW cHandle, SYSTEMTIME * d);
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 TRUE for success, FALSE for failure.

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GetArray
HCkStringArrayW CkXmpW_GetArray(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

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

Returns NULL on failure

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GetEmbedded
HCkXmlW CkXmpW_GetEmbedded(HCkXmpW cHandle, int index);

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

Returns NULL on failure

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GetProperty
HCkXmlW CkXmpW_GetProperty(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

To be documented soon...

Returns NULL on failure

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GetSimpleDate
BOOL CkXmpW_GetSimpleDate(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName, SYSTEMTIME * outSysTime);
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".

Returns TRUE for success, FALSE for failure.

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GetSimpleInt
int CkXmpW_GetSimpleInt(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

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
BOOL CkXmpW_GetSimpleStr(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName, const wchar_t *outStr);
const wchar_t *CkXmpW_getSimpleStr(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

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

Returns TRUE for success, FALSE for failure.

More Information and Examples
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GetStructPropNames
HCkStringArrayW CkXmpW_GetStructPropNames(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *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 NULL on failure

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GetStructValue
BOOL CkXmpW_GetStructValue(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *structName, const wchar_t *propName, const wchar_t *outStr);
const wchar_t *CkXmpW_getStructValue(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *structName, const wchar_t *propName);

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

Returns TRUE for success, FALSE for failure.

More Information and Examples
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LoadAppFile
BOOL CkXmpW_LoadAppFile(HCkXmpW cHandle, const wchar_t *filename);

Loads a TIFF or JPG file into the XMP object.

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LoadFromBuffer
BOOL CkXmpW_LoadFromBuffer(HCkXmpW cHandle, const unsigned char * fileData, const wchar_t *ext);

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

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NewXmp
HCkXmlW CkXmpW_NewXmp(HCkXmpW cHandle);

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

Returns NULL on failure

More Information and Examples
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RemoveAllEmbedded
BOOL CkXmpW_RemoveAllEmbedded(HCkXmpW cHandle);

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 for success, FALSE for failure.

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RemoveArray
BOOL CkXmpW_RemoveArray(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

Removes an XMP array property from the XMP document.

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RemoveEmbedded
BOOL CkXmpW_RemoveEmbedded(HCkXmpW cHandle, int index);

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

Returns TRUE for success, FALSE for failure.

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RemoveNsMapping
void CkXmpW_RemoveNsMapping(HCkXmpW cHandle, const wchar_t *ns);

Removes a namespace-to-URI mapping.

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RemoveSimple
BOOL CkXmpW_RemoveSimple(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *propName);

Removes a simple XMP property from the XMP document.

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RemoveStruct
BOOL CkXmpW_RemoveStruct(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *structName);

Removes an XMP structure property from the XMP document.

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RemoveStructProp
BOOL CkXmpW_RemoveStructProp(HCkXmpW cHandle, HCkXmlW iXml, const wchar_t *structName, const wchar_t *propName);

Removes a single member from an XMP structured property.

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SaveAppFile
BOOL CkXmpW_SaveAppFile(HCkXmpW cHandle, const wchar_t *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.

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SaveLastError
BOOL CkXmpW_SaveLastError(HCkXmpW cHandle, const wchar_t *path);

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns TRUE for success, FALSE for failure.

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SaveToBuffer
BOOL CkXmpW_SaveToBuffer(HCkXmpW cHandle, const unsigned char * outBytes);

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

Returns TRUE for success, FALSE for failure.

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StringToDate
BOOL CkXmpW_StringToDate(HCkXmpW cHandle, const wchar_t *str, SYSTEMTIME * outSysTime);
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).

Returns TRUE for success, FALSE for failure.

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UnlockComponent
BOOL CkXmpW_UnlockComponent(HCkXmpW cHandle, const wchar_t *unlockCode);

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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