OSID - osid.process.StateAssignmentSession Service Interface Definition

Interface	osid.process.StateAssignmentSession
Implements	`osid.OsidSession`
Description	This session provides methods to re-assign `State` to reference `Ids.` A `State` may be associated with multiple reference `ids.` A reference `id` may map to only one `State.`
Method	canAssignStates
Description	Tests if this user can alter state/id mappings. A return of true does not guarantee successful authorization. A return of false indicates that it is known mapping methods in this session will result in a `PERMISSION_DENIED.` This is intended as a hint to an application that may opt not to offer lookup operations to unauthorized users.
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Compliance	`mandatory`		This method must be implemented.
Method	getNextStateIds
Description	Gets the valid states that can be assigned to the reference `id` in the given process.
Parameters	`osid.id.Id`	`referenceId`	a reference `Id`
Parameters	`osid.id.Id`	`processId`	`Id` of the `Process`
Return	`osid.id.IdList`		the `Ids` of the next valid states
Errors	NOT_FOUND		`referenceId` or `processId` is not found
	NULL_ARGUMENT		`referenceId` or `processId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getNextStates
Description	Gets the valid states that can be assigned to a reference `Id` in the given process.
Parameters	`osid.id.Id`	`referenceId`	a reference `Id`
Parameters	`osid.id.Id`	`processId`	`Id` of the `Process`
Return	`osid.process.StateList`		the next valid states
Errors	NOT_FOUND		`referenceId` or `processId` is not found
	NULL_ARGUMENT		`referenceId` or `processId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	assignReferenceToState
Description	Adds a reference `Id` to a `State.`
Parameters	`osid.id.Id`	`referenceId`	a reference `Id`
Parameters	`osid.id.Id`	`stateId`	the `Id` of the `State`
Errors	ALREADY_EXISTS		this `Id` is already assigned to the state
	NOT_FOUND		`stateId` not found
	NULL_ARGUMENT		`id` or `stateId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	unassignReferenceFromState
Description	Removes a reference `Id` from a `State.`
Parameters	`osid.id.Id`	`referenceId`	a reference `Id`
Parameters	`osid.id.Id`	`stateId`	the `Id` of the `State`
Errors	NOT_FOUND		`stateId` not found
	NULL_ARGUMENT		`referenceId` or `stateId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.