Xmp Go Reference Documentation

Xmp

Current Version: 10.0.0

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

Object Creation

xmp := chilkat.NewXmp()
...
xmp.DisposeXmp()

Properties

DebugLogFilePath
func (xmp *Xmp) DebugLogFilePath() string
func (xmp *Xmp) SetDebugLogFilePath(s string)

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
func (xmp *Xmp) LastErrorHtml() string

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
func (xmp *Xmp) LastErrorText() string

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
func (xmp *Xmp) LastErrorXml() string

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
func (xmp *Xmp) LastMethodSuccess() bool
func (xmp *Xmp) SetLastMethodSuccess(b bool)

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
func (xmp *Xmp) NumEmbedded() int

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

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StructInnerDescrip
func (xmp *Xmp) StructInnerDescrip() bool
func (xmp *Xmp) SetStructInnerDescrip(b bool)

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

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UncommonOptions
func (xmp *Xmp) UncommonOptions() string
func (xmp *Xmp) SetUncommonOptions(s string)
Introduced in version 9.5.0.80

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

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VerboseLogging
func (xmp *Xmp) VerboseLogging() bool
func (xmp *Xmp) SetVerboseLogging(b bool)

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
func (xmp *Xmp) Version() string

Version of the component/library, such as "9.5.0.94"

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Methods

AddArray
func (xmp *Xmp) AddArray(xml *Xml, arrType string, propName string, values *StringArray) bool

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".

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AddNsMapping
func (xmp *Xmp) AddNsMapping(ns string, uri string)

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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AddSimpleInt
func (xmp *Xmp) AddSimpleInt(iXml *Xml, propName string, propVal int) bool

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
func (xmp *Xmp) AddSimpleStr(iXml *Xml, propName string, propVal string) bool

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
func (xmp *Xmp) AddStructProp(iChilkatXml *Xml, structName string, propName string, propValue string) bool

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
func (xmp *Xmp) Append(iXml *Xml) bool

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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GetArray
func (xmp *Xmp) GetArray(iXml *Xml, propName string) *StringArray

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
func (xmp *Xmp) GetEmbedded(index int) *Xml

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

Returns nil on failure

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GetProperty
func (xmp *Xmp) GetProperty(iXml *Xml, propName string) *Xml

To be documented soon...

Returns nil on failure

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GetSimpleInt
func (xmp *Xmp) GetSimpleInt(iXml *Xml, propName string) int

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
func (xmp *Xmp) GetSimpleStr(iXml *Xml, propName string) *string

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

Returns nil on failure

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GetStructPropNames
func (xmp *Xmp) GetStructPropNames(iXml *Xml, structName string) *StringArray

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
func (xmp *Xmp) GetStructValue(iXml *Xml, structName string, propName string) *string

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

Returns nil on failure

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LoadAppFile
func (xmp *Xmp) LoadAppFile(filename string) bool

Loads a TIFF or JPG file into the XMP object.

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LoadFromBuffer
func (xmp *Xmp) LoadFromBuffer(fileData []byte, ext string) bool

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

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NewXmp
func (xmp *Xmp) NewXmp() *Xml

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

Returns nil on failure

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RemoveAllEmbedded
func (xmp *Xmp) RemoveAllEmbedded() bool

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
func (xmp *Xmp) RemoveArray(iXml *Xml, propName string) bool

Removes an XMP array property from the XMP document.

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RemoveEmbedded
func (xmp *Xmp) RemoveEmbedded(index int) bool

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
func (xmp *Xmp) RemoveNsMapping(ns string)

Removes a namespace-to-URI mapping.

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RemoveSimple
func (xmp *Xmp) RemoveSimple(iXml *Xml, propName string) bool

Removes a simple XMP property from the XMP document.

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RemoveStruct
func (xmp *Xmp) RemoveStruct(iXml *Xml, structName string) bool

Removes an XMP structure property from the XMP document.

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RemoveStructProp
func (xmp *Xmp) RemoveStructProp(iXml *Xml, structName string, propName string) bool

Removes a single member from an XMP structured property.

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SaveAppFile
func (xmp *Xmp) SaveAppFile(filename string) bool

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
func (xmp *Xmp) SaveToBuffer() []byte

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

Returns nil on failure

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