MSyntax Class Reference
[OpenMaya - API module for common classes]

#include <MSyntax.h>

List of all members.

---

Detailed Description

Syntax for Commands.

This class is used to specify flags and arguments passed to commands. Once the syntax of the command has been defined by calls to the methods in this class, Maya will be able to automatically parse invocations of the command and reject syntactically invalid ones. When the doIt method of the command is invoked, the provided argument list can be parsed automatically into an instance of either the MArgDatabase class (for commands) or MArgParser class (for context commands) by passing the constructor for that class both the argument list and the syntax object for the command.

There are three type of arguments that can be specified via these syntax methods:

• flags arguments preceded by a '-' character.
• command arguments required parameters that follow the flags
• objects an optional list of Maya objects or the contents of the selection list.

Note: command arguments and objects are incompatible and must not be combined in the syntax definition of a command. If an attempt is made to do so, neither command arguments or objects will be accessible via the MArgDatabase or MArgParser classes.

The addFlag method is used to add a flag argument to a command. Flags need to have a type specified for them from the list of available types in the MArgType enum and can take up to six parameters. Flags can be set as being allowed multiple times on the command line be calling the makeFlagMultiUse method.

The addArg method is used to add a command argument to a command. Such arguments must also have a type specified for them from the list of available types in the MArgType enum. If you specify an argument via this call, Maya will reject an invocation of the command as being syntactically invalid if an argument of the correct type is not provided. If the type kSelectionItem is provided, Maya will include the contents of the selection list as the argument to the command.

The setObjectType method is used to specify that the command requires an object list. Parameters to this method allow you to specify minimum and maximum numbers of objects. As well, if the useSelectionAsDefault method is used in conjunction with this, Maya will use the contents of the selection list as the objects for the command if none are specified.

The documentation for the MArgDatabase and MArgParser classes describe how to access the parsed information for a command inside the doIt method of that command.

Examples:

cgfxShaderCmd.cpp, cgfxShaderCmd.h, closestPointOnCurveCmd.cpp, closestPointOnCurveCmd.h, clusterWeightFunction.cpp, conditionTest.cpp, dagMessageCmd.cpp, deletedMsgCmd.cpp, eventTest.cpp, filteredAsciiFile.cpp, flipUVCmd.cpp, flipUVCmd.h, fxManagerCmd.cpp, fxManagerCmd.h, geometryCacheConverter.cpp, geometrySurfaceConstraint.cpp, helixTool.cpp, lockEvent.cpp, narrowPolyViewerCmd.cpp, nodeCreatedCBCmd.cpp, nodeCreatedCBCmd.h, nodeInfoCmd.cpp, particlePathsCmd.cpp, peltOverlapCmd.cpp, renderViewInteractiveRenderCmd.cpp, renderViewRenderCmd.cpp, renderViewRenderRegionCmd.cpp, scanDagSyntax.cpp, userMsgCmd.cpp, and viewCallbackTest.cpp.

Public Types
enum	MArgType {   kInvalidArgType, kNoArg, kBoolean, kLong,   kDouble, kString, kUnsigned, kDistance,   kAngle, kTime, kSelectionItem, kLastArgType }
	Argument types. More...
enum	MObjectFormat {   kInvalidObjectFormat, kNone, kStringObjects, kSelectionList,   kLastObjectFormat }
	Object list types. More...
Public Member Functions
	MSyntax ()
	MSyntax (const MSyntax &other)
virtual	~MSyntax ()
MSyntax &	operator= (const MSyntax &rhs)
MStatus	addFlag (const char *shortName, const char *longName, MArgType argType1=kNoArg, MArgType argType2=kNoArg, MArgType argType3=kNoArg, MArgType argType4=kNoArg, MArgType argType5=kNoArg, MArgType argType6=kNoArg)
MStatus	makeFlagMultiUse (const char *flag)
MStatus	makeFlagQueryWithFullArgs (const char *flag, bool queryArgsAreOptional)
MStatus	addArg (MArgType arg)
void	useSelectionAsDefault (bool useSelectionList=false)
MStatus	setObjectType (MObjectFormat objectFormat, unsigned int minimumObjects=0)
MStatus	setObjectType (MObjectFormat objectFormat, unsigned int minimumObjects, unsigned int maximumObjects)
void	setMinObjects (unsigned int minimumObjectCount)
void	setMaxObjects (unsigned int maximumObjectCount)
void	enableQuery (bool supportsQuery=true)
void	enableEdit (bool supportsEdit=true)
unsigned int	minObjects () const
unsigned int	maxObjects () const
bool	canQuery () const
bool	canEdit () const

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Member Enumeration Documentation

enum MSyntax::MArgType

Argument types.

MPxSelectionContext::argTypeNumericalInput(unsigned int index) const

This method is used by the feedback line to determine what units to display. Users should override this method to return the appropriate argument type for the given index of the numeric input field. Specifically, this method should be overridden to return one of the following:

• MSyntax::kNoArg for no argument
• MSyntax::kDistance for linear units
• MSyntax::kAngle for angular units

Parameters:

[in]

index

the index of the numerical input whose argument type is requested

Returns:

MSyntax::kNoArg the default return value.

Enumerator:

kInvalidArgType
kNoArg
kBoolean
kLong
kDouble
kString
kUnsigned
kDistance
kAngle
kTime
kSelectionItem
kLastArgType

enum MSyntax::MObjectFormat

Object list types.

Enumerator:

kInvalidObjectFormat
kNone
kStringObjects
kSelectionList
kLastObjectFormat

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Constructor & Destructor Documentation

MSyntax::MSyntax

(

)

The default class constructor.

MSyntax::MSyntax

(

const MSyntax &

other

)

The copy constructor.

MSyntax::~MSyntax

(

)

[virtual]

The class destructor.

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Member Function Documentation

MSyntax & MSyntax::operator=

(

const MSyntax &

rhs

)

The assignment operator.

MStatus MSyntax::addFlag	(	const char *	shortName,
		const char *	longName,
		MArgType	argType1 = kNoArg,
		MArgType	argType2 = kNoArg,
		MArgType	argType3 = kNoArg,
		MArgType	argType4 = kNoArg,
		MArgType	argType5 = kNoArg,
		MArgType	argType6 = kNoArg
	)

Adds a flag to the list of flags accepted for the given command. Also specifies any arguments required by the flag.

Parameters:

[in]	shortName	the string representing the short (< 4 character) version of the flag
[in]	longName	the string representing the int (> 3 character) version of the flag
[in]	argType1	type of the argument required by the flag, if any
[in]	argType2	another type of the argument required by the flag, if any
[in]	argType3	another type of the argument required by the flag, if any
[in]	argType4	another type of the argument required by the flag, if any
[in]	argType5	another type of the argument required by the flag, if any
[in]	argType6	another type of the argument required by the flag, if any

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

Examples:

cgfxShaderCmd.cpp, closestPointOnCurveCmd.cpp, clusterWeightFunction.cpp, conditionTest.cpp, dagMessageCmd.cpp, eventTest.cpp, filteredAsciiFile.cpp, flipUVCmd.cpp, fxManagerCmd.cpp, geometryCacheConverter.cpp, geometrySurfaceConstraint.cpp, helixTool.cpp, lockEvent.cpp, narrowPolyViewerCmd.cpp, nodeCreatedCBCmd.cpp, nodeInfoCmd.cpp, particlePathsCmd.cpp, peltOverlapCmd.cpp, renderViewInteractiveRenderCmd.cpp, renderViewRenderCmd.cpp, renderViewRenderRegionCmd.cpp, scanDagSyntax.cpp, userMsgCmd.cpp, and viewCallbackTest.cpp.

MStatus MSyntax::makeFlagMultiUse

(

const char *

flag

)

Specifies that the given flag can be used by the command multiple times in on the same command line.

Parameters:

[in]

flag

the flag to be made multi-use

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

Examples:

geometryCacheConverter.cpp.

MStatus MSyntax::makeFlagQueryWithFullArgs	(	const char *	flag,
		bool	queryArgsAreOptional
	)

Specifies that the given flag will require all of its arguments in query mode. Usually flags do not take arguments in query mode, since you are getting values instead of setting them. However, sometimes it is necessary to take arguments on a flag to allow the user to provide information which will help specify the scope of a query.

Note that query arguments may be set to be optional. In that case the flag will be accepted with arguments or without. In that case, you must check at runtime to see how many arguments where passed to the flag.

Parameters:

[in]	flag	the flag which should be set to use arguments during query
[in]	queryArgsAreOptional	set to true if the flag arguments are optional

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

MStatus MSyntax::addArg

(

MArgType

arg

)

Specifies the type of one of the arguments to the command. This method can be called multiple times to specify multiple arguments to the command.

Parameters:

[in]

arg

the type of the argument to the command

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

Examples:

viewCallbackTest.cpp.

void MSyntax::useSelectionAsDefault

(

bool

useSelectionList = false

)

Specifies that the command will use the current selection list as arguments to the command if the command requires objects and none are provided}.

Parameters:

[in]

useSelectionList

if true, the command will use the current selection list as arguments if none are specified

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

Examples:

closestPointOnCurveCmd.cpp, dagMessageCmd.cpp, deletedMsgCmd.cpp, lockEvent.cpp, and particlePathsCmd.cpp.

MStatus MSyntax::setObjectType	(	MObjectFormat	objectFormat,
		unsigned int	minimumObjects = 0
	)

Specifies the representation of the objects passed to the command as either MObjects or MStrings. Also specifies the minimum number of objects required by the command.

Parameters:

[in]	objectFormat	the form of the objects passed to the command
[in]	minimumObjects	the minimum number of objects required by the command

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

Examples:

cgfxShaderCmd.cpp, closestPointOnCurveCmd.cpp, conditionTest.cpp, dagMessageCmd.cpp, deletedMsgCmd.cpp, eventTest.cpp, lockEvent.cpp, particlePathsCmd.cpp, and peltOverlapCmd.cpp.

MStatus MSyntax::setObjectType	(	MObjectFormat	objectFormat,
		unsigned int	minimumObjects,
		unsigned int	maximumObjects
	)

Specifies the representation of the objects passed to the command as either MObjects or MStrings. Also specifies the upper and lower limits of the number of objects accepted by the command.

Parameters:

[in]	objectFormat	the form of the objects passed to the command
[in]	minimumObjects	the lower limit of the number of objects
[in]	maximumObjects	the upper limit of the number of objects

Returns:

• MS::kSuccess operation successful
• MS::kFailure operation failed

void MSyntax::setMinObjects

(

unsigned int

minimumObjectCount

)

Specifies the lower limit on the number of objects accepted by the command.

Parameters:

[in]

minimumObjectCount

the lower limit of the number of objects

Examples:

dagMessageCmd.cpp, and deletedMsgCmd.cpp.

void MSyntax::setMaxObjects

(

unsigned int

maximumObjectCount

)

Specifies the upper limit on the number of objects accepted by the command.

Parameters:

[in]

maximumObjectCount

the upper limit of the number of objects

void MSyntax::enableQuery

(

bool

supportsQuery = true

)

Sets whether or not the command supports the query flag ("-q").

Parameters:

[in]

supportsQuery

if true, the command supports the query flag

Examples:

cgfxShaderCmd.cpp, closestPointOnCurveCmd.cpp, and geometryCacheConverter.cpp.

void MSyntax::enableEdit

(

bool

supportsEdit = true

)

Sets whether or not the command supports the edit flag ("-e").

Parameters:

[in]

supportsEdit

if true, the command supports the edit flag

Examples:

cgfxShaderCmd.cpp, closestPointOnCurveCmd.cpp, and geometryCacheConverter.cpp.

unsigned int MSyntax::minObjects

(

)

const

Returns the lower limit on the number of objects accepted by the command.

Returns:

The minimum number of objects

unsigned int MSyntax::maxObjects

(

)

const

Returns the upper limit on the number of objects accepted by the command.

Returns:

The maximum number of objects

bool MSyntax::canQuery

(

)

const

Returns whether or not the command supports the query flag ("-q").

Returns:

• true can query
• false cannot query

bool MSyntax::canEdit

(

)

const

Returns whether or not the command supports the edit flag ("-e").

Returns:

• true can edit
• false cannot edit