OSID - osid.checklist.TodoChecklistAssignmentSession Service Interface Definition

Interface	osid.checklist.TodoChecklistAssignmentSession
Implements	`osid.OsidSession`
Description	This session provides methods to re-assign `Todos` to `Checklists.` A `Todo` may map to multiple `Checklists` and removing the last reference to a `Todo` is the equivalent of deleting it. Each `Checklist` may have its own authorizations governing who is allowed to operate on it. Adding a reference of a `Todo` to another `Checklist` is not a copy operation (eg: does not change its `Id` ).
Method	canAssignTodos
Description	Tests if this user can alter todo/checklist 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	canAssignTodosToChecklist
Description	Tests if this user can alter todo/checklist 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`	`checklistId`	the `Id` of the `Checklist`
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Errors	NULL_ARGUMENT		`checklistId` is `null`
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableChecklistIds
Description	Gets a list of checklists including and under the given checklist node in which any todo can be assigned.
Parameters	`osid.id.Id`	`checklistId`	the `Id` of the `Checklist`
Return	`osid.id.IdList`		list of assignable checklist `Ids`
Errors	NULL_ARGUMENT		`checklistId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableChecklistIdsForTodo
Description	Gets a list of checklists including and under the given checklist node in which a specific todo can be assigned.
Parameters	`osid.id.Id`	`checklistId`	the `Id` of the `Checklist`
Parameters	`osid.id.Id`	`todoId`	the `Id` of the `Todo`
Return	`osid.id.IdList`		list of assignable checklist `Ids`
Errors	NULL_ARGUMENT		`checklistId` or `todoId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	assignTodoToChecklist
Description	Adds an existing `Todo` to a `Checklist.`
Parameters	`osid.id.Id`	`todoId`	the `Id` of the `Todo`
Parameters	`osid.id.Id`	`checklistId`	the `Id` of the `Checklist`
Errors	ALREADY_EXISTS		`todoId` is already assigned to `checklistId`
	NOT_FOUND		`todoId` or `checklistId` not found
	NULL_ARGUMENT		`todoId` or `checklistId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	unassignTodoFromChecklist
Description	Removes a `Todo` from a `Checklist.`
Parameters	`osid.id.Id`	`todoId`	the `Id` of the `Todo`
Parameters	`osid.id.Id`	`checklistId`	the `Id` of the `Checklist`
Errors	NOT_FOUND		`todoId` or `checklistId` not found or `todoId` is not assigned to `checklistId`
	NULL_ARGUMENT		`todoId` or `checklistId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	reassignTodoToChecklist
Description	Moves a `Todo` from one `Checklist` to another. Mappings to other `Checklists` are unaffected.
Parameters	`osid.id.Id`	`todoId`	the `Id` of the `Todo`
	`osid.id.Id`	`fromChecklistId`	the `Id` of the current `Checklist`
	`osid.id.Id`	`toChecklistId`	the `Id` of the destination `Checklist`
Errors	NOT_FOUND		`todoId, fromChecklistId,` or `toChecklistId` not found or `todoId` not mapped to `fromChecklistId`
	NULL_ARGUMENT		`todoId, fromChecklistId,` or `toChecklistId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.