CkXmp Ruby Reference Documentation

CkXmp

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

Object Creation

obj = Chilkat::CkXmp.new()

Properties

# strVal is a string
# ckStr is a CkString
xmp.get_DebugLogFilePath(ckStr);
strVal = xmp.debugLogFilePath();
xmp.put_DebugLogFilePath(strVal);

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.

# strVal is a string
# ckStr is a CkString
xmp.get_LastErrorHtml(ckStr);
strVal = xmp.lastErrorHtml();

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.

# strVal is a string
# ckStr is a CkString
xmp.get_LastErrorText(ckStr);
strVal = xmp.lastErrorText();

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.

# strVal is a string
# ckStr is a CkString
xmp.get_LastErrorXml(ckStr);
strVal = xmp.lastErrorXml();

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.

# boolVal is a boolean
boolVal = xmp.get_LastMethodSuccess();
xmp.put_LastMethodSuccess(boolVal);

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.

# intVal is an integer
intVal = xmp.get_NumEmbedded();

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

# boolVal is a boolean
boolVal = xmp.get_StructInnerDescrip();
xmp.put_StructInnerDescrip(boolVal);

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

# boolVal is a boolean
boolVal = xmp.get_Utf8();
xmp.put_Utf8(boolVal);

When set to true, all "const char *" arguments are interpreted as utf-8 strings. If set to false (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to true, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to false, all "const char *" return values are ANSI strings.

# boolVal is a boolean
boolVal = xmp.get_VerboseLogging();
xmp.put_VerboseLogging(boolVal);

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.

# strVal is a string
# ckStr is a CkString
xmp.get_Version(ckStr);
strVal = xmp.version();

Version of the component/library, such as "9.4.1.42"

Methods

# xml is a CkXml
# arrType is a string
# propName is a string
# values is a CkStringArray
retBool = xmp.AddArray(xml, arrType, propName, 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".

XMP Array Property - Bag, Seq, or Alt

# ns is a string
# uri is a string
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.

# iXml is a CkXml
# propName is a string
# propVal is an integer
retBool = xmp.AddSimpleInt(iXml, propName, 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".

# iXml is a CkXml
# propName is a string
# propVal is a string
retBool = xmp.AddSimpleStr(iXml, propName, 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".

# iChilkatXml is a CkXml
# structName is a string
# propName is a string
# propValue is a string
retBool = xmp.AddStructProp(iChilkatXml, structName, propName, 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".

# iXml is a CkXml
retBool = xmp.Append(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.

# returns a CkStringArray
# iXml is a CkXml
# propName is a string
ret_stringArray = xmp.GetArray(iXml, propName);

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

# returns a CkXml
# index is an integer
ret_xml = xmp.GetEmbedded(index);

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

# returns a CkXml
# iXml is a CkXml
# propName is a string
ret_xml = xmp.GetProperty(iXml, propName);

To be documented soon...

# iXml is a CkXml
# propName is a string
retInt = xmp.GetSimpleInt(iXml, propName);

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

# iXml is a CkXml
# propName is a string
# outStr is a CkString (output)
status = xmp.GetSimpleStr(iXml, propName, outStr);
retStr = xmp.getSimpleStr(iXml, 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.

Get a String Property Value from XMP

# returns a CkStringArray
# iXml is a CkXml
# structName is a string
ret_stringArray = xmp.GetStructPropNames(iXml, 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.

# iXml is a CkXml
# structName is a string
# propName is a string
# outStr is a CkString (output)
status = xmp.GetStructValue(iXml, structName, propName, outStr);
retStr = xmp.getStructValue(iXml, structName, 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.

Get a Structure Property Value from XMP

# filename is a string
retBool = xmp.LoadAppFile(filename);

Loads a TIFF or JPG file into the XMP object.

# fileData is a CkByteData
# ext is a string
retBool = xmp.LoadFromBuffer(fileData, ext);

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

# returns a CkXml
ret_xml = xmp.NewXmp();

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

Add XMP MetaData to JPG or TIFF

status = xmp.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 true for success, false for failure.

# iXml is a CkXml
# propName is a string
retBool = xmp.RemoveArray(iXml, propName);

Removes an XMP array property from the XMP document.

# index is an integer
status = xmp.RemoveEmbedded(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.

# ns is a string
xmp.RemoveNsMapping(ns);

Removes a namespace-to-URI mapping.

# iXml is a CkXml
# propName is a string
retBool = xmp.RemoveSimple(iXml, propName);

Removes a simple XMP property from the XMP document.

# iXml is a CkXml
# structName is a string
retBool = xmp.RemoveStruct(iXml, structName);

Removes an XMP structure property from the XMP document.

# iXml is a CkXml
# structName is a string
# propName is a string
retBool = xmp.RemoveStructProp(iXml, structName, propName);

Removes a single member from an XMP structured property.

# filename is a string
retBool = xmp.SaveAppFile(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.

# path is a string
status = xmp.SaveLastError(path);

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

Returns true for success, false for failure.

# outBytes is a CkByteData (output)
status = xmp.SaveToBuffer(outBytes);

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

Returns true for success, false for failure.

# unlockCode is a string
retBool = xmp.UnlockComponent(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 permanent unlock code is required to use the component beyond 30 days.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Permanent Unlock Code

LastErrorText Standard Information