OSID - osid.topology.NodeGraphAssignmentSession Service Interface Definition

Interface	osid.topology.NodeGraphAssignmentSession
Implements	`osid.OsidSession`
Description	This session provides methods to re-assign `Nodes` to `Graph` objects A `Node` may appear in multiple `Graph` objects and removing the last reference to a `Node` is the equivalent of deleting it. Each `Graph` may have its own authorizations governing who is allowed to operate on it. Adding a reference of a `Node` to another `Graph` is not a copy operation (eg: does not change its `Id` ).
Method	canAssignNodes
Description	Tests if this user can alter node/graph 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 assignment operations to unauthorized users.
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Compliance	`mandatory`		This method must be implemented.
Method	canAssignNodesToGraph
Description	Tests if this user can alter node/graph 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 assignment operations to unauthorized users.
Parameters	`osid.id.Id`	`graphId`	the `Id` of the `Graph`
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Errors	NULL_ARGUMENT		`graphId` is `null`
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableGraphIds
Description	Gets a list of graphs including and under the given graph node in which any node can be assigned.
Parameters	`osid.id.Id`	`graphId`	the `Id` of the `Graph`
Return	`osid.id.IdList`		list of assignable graph `Ids`
Errors	NULL_ARGUMENT		`graphId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableGraphIdsForNode
Description	Gets a list of graphs including and under the given graph node in which a specific node can be assigned.
Parameters	`osid.id.Id`	`graphId`	the `Id` of the `Graph`
Parameters	`osid.id.Id`	`nodeId`	the `Id` of the `Node`
Return	`osid.id.IdList`		list of assignable graph `Ids`
Errors	NULL_ARGUMENT		`graphId` or `nodeId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	assignNodeToGraph
Description	Adds an existing `Node` to a `Graph.`
Parameters	`osid.id.Id`	`nodeId`	the `Id` of the `Node`
Parameters	`osid.id.Id`	`graphId`	the `Id` of the `Graph`
Errors	ALREADY_EXISTS		`nodeId` is already assigned to `graphId`
	NOT_FOUND		`nodeId` or `graphId` not found
	NULL_ARGUMENT		`nodeId` or `graphId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	unassignNodeFromGraph
Description	Removes a `Node` from a `Graph.`
Parameters	`osid.id.Id`	`nodeId`	the `Id` of the `Node`
Parameters	`osid.id.Id`	`graphId`	the `Id` of the `Graph`
Errors	NOT_FOUND		`nodeId` or `graphId` not found or `nodeId` not assigned to `graphId`
	NULL_ARGUMENT		`nodeId` or `graphId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	reassignNodeToGraph
Description	Moves a `Node` from one `Graph` to another. Mappings to other `Graphs` are unaffected.
Parameters	`osid.id.Id`	`nodeId`	the `Id` of the `Node`
	`osid.id.Id`	`fromGraphId`	the `Id` of the current `Graph`
	`osid.id.Id`	`toGraphId`	the `Id` of the destination `Graph`
Errors	NOT_FOUND		`nodeId, fromGraphId,` or `toGraphId` not found or `nodeId` not mapped to `fromGraphId`
	NULL_ARGUMENT		`nodeId, fromGraphId,` or `toGraphId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.