MFnMessageAttribute Class Reference

#include <MFnMessageAttribute.h>

Class Description

Message attribute function set.

Function set for message attributes. A message attribute is a dependency node attribute that does not transmit data. Message attributes only exist to formally declare relationships between nodes. By connecting two nodes via message attributes, a relationship between those nodes is expressed. Message attribute connections can be traversed in the same manner as any other connection in the dependency graph.

Examples:

Inheritance diagram for MFnMessageAttribute:

Public Member Functions
virtual MFn::Type	type () const
	Function set type. More...
virtual	~MFnMessageAttribute ()
	Destructor.
	MFnMessageAttribute ()
	Default constructor.
	MFnMessageAttribute (MObject &object, MStatus *ReturnStatus=NULL)
	Constructor. More...
MObject	create (const MString &fullName, const MString &briefName, MStatus *ReturnStatus=NULL)
	Creates a Message attribute object. More...
	MFnMessageAttribute (const MObject &object, MStatus *ReturnStatus=NULL)
	Constructor. More...
Public Member Functions inherited from MFnAttribute
virtual	~MFnAttribute ()
	Destructor.
	MFnAttribute ()
	Default constructor.
	MFnAttribute (MObject &object, MStatus *ReturnStatus=NULL)
	Constructor. More...
bool	isReadable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is readable. More...
bool	isWritable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is writable. More...
bool	isConnectable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute accepts dependency graph connections. More...
bool	isStorable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be stored when the node is saved to a file. More...
bool	isCached (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is cached locally in the node's data block. More...
bool	isArray (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute supports an array of data. More...
bool	indexMatters (MStatus *ReturnStatus=NULL) const
	Determines whether the user must specify an index when connecting to this attribute, or whether the next available index can be used. More...
bool	isKeyable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is keyable. More...
bool	isChannelBoxFlagSet (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute has its channel box flag set. More...
bool	isHidden (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to hidden from the UI. More...
bool	isUsedAsColor (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be presented as a color in the UI. More...
bool	isIndeterminant (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is indeterminant. More...
bool	isRenderSource (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a render source. More...
bool	isDynamic (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a dynamic attribute. More...
bool	isExtension (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is an extension attribute. More...
bool	isWorldSpace (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is worldspace. More...
bool	isAffectsWorldSpace (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute affects worldspace. More...
bool	isUsedAsFilename (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be used as a filename. More...
bool	affectsAppearance (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute affects the appearance of the object when rendering in the viewport. More...
bool	isProxyAttribute (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a proxy attribute. More...
DisconnectBehavior	disconnectBehavior (MStatus *ReturnStatus=NULL) const
	Returns the behavior of this attribute when it is disconnected. More...
bool	usesArrayDataBuilder (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute uses an array data builder. More...
bool	internal (MStatus *ReturnStatus=NULL) const
	Returns true if a node has internal member data representing this attribute. More...
MStatus	setReadable (bool state)
	Sets whether this attribute should be readable. More...
MStatus	setWritable (bool state)
	Sets whether this attribute should be writable. More...
MStatus	setConnectable (bool state)
	Sets whether this attribute should allow dependency graph connections. More...
MStatus	setStorable (bool state)
	Sets whether this attribute should be storable. More...
MStatus	setCached (bool state)
	Sets whether the data for this attribute is cached locally in the node's data block. More...
MStatus	setArray (bool state)
	Sets whether this attribute should have an array of data. More...
MStatus	setIndexMatters (bool state)
	If the attribute is an array, then this method specifies whether to force the user to specify an index when connecting to this attribute, or to use the next available index. More...
MStatus	setKeyable (bool state)
	Sets whether this attribute should accept keyframe data. More...
MStatus	setChannelBox (bool state)
	Sets whether this attribute should appear in the channel box when the node is selected. More...
MStatus	setHidden (bool state)
	Sets whether this attribute should be hidden from the UI. More...
MStatus	setUsedAsColor (bool state)
	Sets whether this attribute should be presented as a color in the UI. More...
MStatus	setIndeterminant (bool state)
	Sets whether this attribute is indeterminant. More...
MStatus	setRenderSource (bool state)
	Sets whether this attribute should be used as a render source attribute. More...
MStatus	setWorldSpace (bool state)
	Sets whether this attribute should be treated as worldspace. More...
MStatus	setAffectsWorldSpace (bool state)
	Sets whether this attribute should affect worldspace. More...
MStatus	setUsedAsFilename (bool state)
	Sets whether this attribute should be presented as a filename in the UI. More...
MStatus	setAffectsAppearance (bool state)
	Sets whether this attribute affects the appearance of the object when rendering in the viewport. More...
MStatus	setProxyAttribute (bool state)
	Sets whether this attribute is a proxy attribute. More...
MStatus	setDisconnectBehavior (DisconnectBehavior behavior)
	Sets the disconnection behavior for this attribute. More...
MStatus	setUsesArrayDataBuilder (bool state)
	Sets whether this attribute uses an array data builder. More...
MStatus	setInternal (bool state)
	The function controls an attribute's data storage. More...
MStatus	setNiceNameOverride (const MString &localizedName)
	Sets the localized string which should be used for this attribute in the UI. More...
bool	acceptsAttribute (const MFnAttribute &attr, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection with the given attribute. More...
bool	accepts (MFnData::Type type, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection of the given type. More...
bool	accepts (const MTypeId &id, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection of the given type. More...
MObject	parent (MStatus *ReturnStatus=NULL) const
	Get the parent of this attribute, if it has one. More...
MString	name (MStatus *ReturnStatus=NULL) const
	Returns the long name of the attribute. More...
MString	shortName (MStatus *ReturnStatus=NULL) const
	Returns the short name of the attribute. More...
MString	getAddAttrCmd (bool useLongName=false, MStatus *status=NULL) const
	Returns a string containing the addAttr command which would be required to recreate the attribute on a node. More...
MStatus	addToCategory (const MString &category)
	Add the attribute to the named category. More...
MStatus	removeFromCategory (const MString &category)
	Remove the attribute from the named category. More...
bool	hasCategory (const MString &category) const
	Check to see if the attribute belongs to the named category. More...
MStatus	getCategories (MStringArray &ReturnStatus) const
	Get all of the categories to which this attribute belongs. More...
	MFnAttribute (const MObject &object, MStatus *ReturnStatus=NULL)
	NO SCRIPT SUPPORT. More...
Public Member Functions inherited from MFnBase
virtual	~MFnBase ()
	Class Destructor. More...
bool	hasObj (MFn::Type) const
	Determines whether or not the Function Set is compatible with the specified Maya Object within the API RTTI system. More...
bool	hasObj (const MObject &) const
	Determines whether or not the Function Set is compatible with the specified Maya Object within the API RTTI system. More...
MObject	object (MStatus *ReturnStatus=NULL) const
	Returns the MObject that is attached to the Function Set. More...
virtual MStatus	setObject (MObject &object)
	Attaches the Function Set to the specified Maya Object. More...
virtual MStatus	setObject (const MObject &object)
	NO SCRIPT SUPPORT. More...

Protected Member Functions
virtual const char *	className () const
	Class name. More...

Additional Inherited Members
Public Types inherited from MFnAttribute
enum	DisconnectBehavior { kDelete, kReset, kNothing }
	Attribute behaviour on disconnect. More...
Static Public Member Functions inherited from MFnBase
static const char *	className ()
	Returns the name of this class. More...

Constructor & Destructor Documentation

MFnMessageAttribute	(	MObject &	object,
		MStatus *	ReturnStatus = NULL
	)

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

• MS::kSuccess if the function set is successfully attached
• MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

MFnMessageAttribute	(	const MObject &	object,
		MStatus *	ReturnStatus = NULL
	)

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

• MS::kSuccess if the function set is successfully attached
• MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

Member Function Documentation

MFn::Type type ( ) const

virtual

Function set type.

Return the class type : MFn::kMessageAttribute.

Reimplemented from MFnAttribute.

const char * className ( ) const

protectedvirtual

Class name.

Return the class name : "MFnMessageAttribute".

Reimplemented from MFnAttribute.

MObject create	(	const MString &	fullName,
		const MString &	briefName,
		MStatus *	ReturnStatus = NULL
	)

Creates a Message attribute object.

The create method needs to be called on a per node basis. That means if you want to create and add the same attribute to multiple nodes, you need to call the create method for each node to get a unique MObject back. If you call create just once and add the attribute to multiple nodes, Maya will encounter a fatal error.

Parameters

[in]	fullName	The full name of the attribute
[in]	briefName	The brief name of the attribute
[out]	ReturnStatus	Status code for the operation.

Returns

The newly created Message attribute object.

Status Codes:

• MS::kSuccess The attribute object was successfully created.
• MS::kFailure Failure during attribute creation.

Examples:

---

The documentation for this class was generated from the following files:

• MFnMessageAttribute.h
• MFnMessageAttribute.cpp