OSID - osid.checklist.TodoHierarchySession Service Interface Definition

Interface	osid.checklist.TodoHierarchySession
Implements	`osid.OsidSession`
Description	This session defines methods for traversing a hierarchy of `Todo` objects. Each todo in the hierarchy is a unique `Todo.` The hierarchy may be traversed recursively to establish the tree structure through `getParentTodos()` and `getChildTodos().` To relate these `Ids` to another OSID, `getTodoNodes()` can be used for retrievals that can be used for bulk lookups in other OSIDs. Any `Todo` available in the Course OSID is known to this hierarchy but does not appear in the hierarchy traversal until added as a root node or a child of another node. A user may not be authorized to traverse the entire hierarchy. Parts of the hierarchy may be made invisible through omission from the returns of `getParentTodos()` or `getChildTodos()` in lieu of a `PERMISSION_DENIED` error that may disrupt the traversal through authorized pathways. This session defines views that offer differing behaviors when retrieving multiple objects. comparative view: todo elements may be silently omitted or re-ordered plenary view: provides a complete set or is an error condition
Method	getTodoHierarchyId
Description	Gets the hierarchy `Id` associated with this session.
Return	`osid.id.Id`		the hierarchy `Id` associated with this session
Compliance	`mandatory`		This method must be implemented.
Method	getTodoHierarchy
Description	Gets the hierarchy associated with this session.
Return	`osid.hierarchy.Hierarchy`		the hierarchy associated with this session
Errors	OPERATION_FAILED		unable to complete request
Errors	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	canAccessTodoHierarchy
Description	Tests if this user can perform hierarchy queries. A return of true does not guarantee successful authorization. A return of false indicates that it is known all 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.
Return	`boolean`		`false` if hierarchy traversal methods are not authorized, `true` otherwise
Compliance	`mandatory`		This method must be implemented.
Method	useComparativeTodoView
Description	The returns from the todo methods may omit or translate elements based on this session, such as authorization, and not result in an error. This view is used when greater interoperability is desired at the expense of precision.
Compliance	`mandatory`		This method is must be implemented.
Method	usePlenaryTodoView
Description	A complete view of the `Todos` returns is desired. Methods will return what is requested or result in an error. This view is used when greater precision is desired at the expense of interoperability.
Compliance	`mandatory`		This method is must be implemented.
Method	getRootTodoIds
Description	Gets the root todo `Ids` in this hierarchy.
Return	`osid.id.IdList`		the root todo `Ids`
Errors	OPERATION_FAILED		unable to complete request
Errors	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getRootTodos
Description	Gets the root todos in the todo hierarchy. A node with no parents is an orphan. While all todo `Ids` are known to the hierarchy, an orphan does not appear in the hierarchy unless explicitly added as a root node or child of another node.
Return	`osid.checklist.TodoList`		the root todos
Errors	OPERATION_FAILED		unable to complete request
Errors	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method is must be implemented.
Method	hasParentTodos
Description	Tests if the `Todo` has any parents.
Parameters	`osid.id.Id`	`todoId`	a todo `Id`
Return	`boolean`		`true` if the todo has parents, `false` otherwise
Errors	NOT_FOUND		`todoId` is not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isParentOfTodo
Description	Tests if an `Id` is a direct parent of todo.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`todoId`	the `Id` of a todo
Return	`boolean`		`true` if this `id` is a parent of `todoId,` `false` otherwise
Errors	NOT_FOUND		`todoId` is not found
	NULL_ARGUMENT		`id` or `todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Provider Notes	If `id` not found return `false.`
Method	getParentTodoIds
Description	Gets the parent `Ids` of the given todo.
Parameters	`osid.id.Id`	`todoId`	a todo `Id`
Return	`osid.id.IdList`		the parent `Ids` of the todo
Errors	NOT_FOUND		`todoId` is not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getParentTodos
Description	Gets the parents of the given todo.
Parameters	`osid.id.Id`	`todoId`	the `Id` to query
Return	`osid.checklist.TodoList`		the parents of the todo
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isAncestorOfTodo
Description	Tests if an `Id` is an ancestor of a todo.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`todoId`	the `Id` of a todo
Return	`boolean`		`true` if this `id` is an ancestor of `todoId,` `false` otherwise
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`id` or `todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Provider Notes	If `id` not found return `false.`
Method	hasChildTodos
Description	Tests if a todo has any children.
Parameters	`osid.id.Id`	`todoId`	a todo `Id`
Return	`boolean`		`true` if the `todoId` has children, `false` otherwise
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isChildOfTodo
Description	Tests if a node is a direct child of another.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`todoId`	the `Id` of a todo
Return	`boolean`		`true` if the `id` is a child of `todoId,` `false` otherwise
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Provider Notes	If `id` not found return `false.`
Method	getChildTodoIds
Description	Gets the child `Ids` of the given todo.
Parameters	`osid.id.Id`	`todoId`	a todo `Id`
Return	`osid.id.IdList`		the child `Ids` of the todo
Errors	NOT_FOUND		`todoId` is not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getChildTodos
Description	Gets the children of the given todo.
Parameters	`osid.id.Id`	`todoId`	the `Id` to query
Return	`osid.checklist.TodoList`		the children of the todo
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isDescendantOfTodo
Description	Tests if an `Id` is a descendant of a todo.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`todoId`	the `Id` of a todo
Return	`boolean`		`true` if the `id` is a descendant of the `todoId,` `false` otherwise
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` or `id` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Provider Notes	If `id` is not found return `false.`
Method	getTodoNodeIds
Description	Gets a portion of the hierarchy for the given todo.
Parameters	`osid.id.Id`	`todoId`	the `Id` to query
	`cardinal`	`ancestorLevels`	the maximum number of ancestor levels to include. A value of 0 returns no parents in the node.
	`cardinal`	`descendantLevels`	the maximum number of descendant levels to include. A value of 0 returns no children in the node.
	`boolean`	`includeSiblings`	`true` to include the siblings of the given node, `false` to omit the siblings
Return	`osid.hierarchy.Node`		a todo node
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getTodoNodes
Description	Gets a portion of the hierarchy for the given todo.
Parameters	`osid.id.Id`	`todoId`	the `Id` to query
	`cardinal`	`ancestorLevels`	the maximum number of ancestor levels to include. A value of 0 returns no parents in the node.
	`cardinal`	`descendantLevels`	the maximum number of descendant levels to include. A value of 0 returns no children in the node.
	`boolean`	`includeSiblings`	`true` to include the siblings of the given node, `false` to omit the siblings
Return	`osid.checklist.TodoNode`		a todo node
Errors	NOT_FOUND		`todoId` not found
	NULL_ARGUMENT		`todoId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.