OSID - osid.control.SystemHierarchySession Service Interface Definition

Interface	osid.control.SystemHierarchySession
Implements	`osid.OsidSession`
Description	This session defines methods for traversing a hierarchy of `System` objects. Each node in the hierarchy is a unique `System.` The hierarchy may be traversed recursively to establish the tree structure through `getParentSystems()` and `getChildSystems().` To relate these `Ids` to another OSID, `getSystemNodes()` can be used for retrievals that can be used for bulk lookups in other OSIDs. Any `System` available in the Control OSID is known to this hierarchy but does not appear in the hierarchy traversal until added as a root system or a child of another system. 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 `getParentSystems()` or `getChildSystems()` in lieu of a `PERMISSION_DENIED` error that may disrupt the traversal through authorized deviceways. This session defines views that offer differing behaviors when retrieving multiple objects. comparative system view: system elements may be silently omitted or re-ordered plenary system view: provides a complete set or is an error condition
Method	getSystemHierarchyId
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	getSystemHierarchy
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	canAccessSystemHierarchy
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	useComparativeSystemView
Description	The returns from the system 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	usePlenarySystemView
Description	A complete view of the `Systems` 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	getRootSystemIds
Description	Gets the root system `Ids` in this hierarchy.
Return	`osid.id.IdList`		the root system `Ids`
Errors	OPERATION_FAILED		unable to complete request
Errors	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getRootSystems
Description	Gets the root system in the system hierarchy. A system with no parents is an orphan. While all system `Ids` are known to the hierarchy, an orphan does not appear in the hierarchy unless explicitly added as a root system or child of another system.
Return	`osid.control.SystemList`		the root systems
Errors	OPERATION_FAILED		unable to complete request
Errors	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method is must be implemented.
Method	hasParentSystems
Description	Tests if the `System` has any parents.
Parameters	`osid.id.Id`	`systemId`	a system `Id`
Return	`boolean`		`true` if the system has parents, f `alse` otherwise
Errors	NOT_FOUND		`systemId` is not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isParentOfSystem
Description	Tests if an `Id` is a direct parent of system.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`systemId`	the `Id` of a system
Return	`boolean`		`true` if this `id` is a parent of `systemId,` f `alse` otherwise
Errors	NOT_FOUND		`systemId` is not found
	NULL_ARGUMENT		`id` or `systemId` 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	getParentSystemIds
Description	Gets the parent `Ids` of the given system.
Parameters	`osid.id.Id`	`systemId`	a system `Id`
Return	`osid.id.IdList`		the parent `Ids` of the system
Errors	NOT_FOUND		`systemId` is not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getParentSystems
Description	Gets the parents of the given system.
Parameters	`osid.id.Id`	`systemId`	the `Id` to query
Return	`osid.control.SystemList`		the parents of the system
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isAncestorOfSystem
Description	Tests if an `Id` is an ancestor of a system.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`systemId`	the `Id` of a system
Return	`boolean`		`tru` e if this `id` is an ancestor of `systemId,` `false` otherwise
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` 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` not found return `false.`
Method	hasChildSystems
Description	Tests if a system has any children.
Parameters	`osid.id.Id`	`systemId`	a system `Id`
Return	`boolean`		`true` if the `systemId` has children, `false` otherwise
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isChildOfSystem
Description	Tests if a system is a direct child of another.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`systemId`	the `Id` of a system
Return	`boolean`		`true` if the `id` is a child of `systemId,` `false` otherwise
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`id` or `systemId` 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	getChildSystemIds
Description	Gets the child `Ids` of the given system.
Parameters	`osid.id.Id`	`systemId`	the `Id` to query
Return	`osid.id.IdList`		the children of the system
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getChildSystems
Description	Gets the children of the given system.
Parameters	`osid.id.Id`	`systemId`	the `Id` to query
Return	`osid.control.SystemList`		the children of the system
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	isDescendantOfSystem
Description	Tests if an `Id` is a descendant of a system.
Parameters	`osid.id.Id`	`id`	an `Id`
Parameters	`osid.id.Id`	`systemId`	the `Id` of a system
Return	`boolean`		`true` if the `id` is a descendant of the `systemId,` `false` otherwise
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`id` or `systemId` 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	getSystemNodeIds
Description	Gets a portion of the hierarchy for the given system.
Parameters	`osid.id.Id`	`systemId`	the `Id` to query
	`cardinal`	`ancestorLevels`	the maximum number of ancestor levels to include. A value of 0 returns no parents in the system.
	`cardinal`	`descendantLevels`	the maximum number of descendant levels to include. A value of 0 returns no children in the system.
	`boolean`	`includeSiblings`	`true` to include the siblings of the given system, `false` to omit the siblings
Return	`osid.hierarchy.Node`		a system node
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	getSystemNodes
Description	Gets a portion of the hierarchy for the given system.
Parameters	`osid.id.Id`	`systemId`	the `Id` to query
	`cardinal`	`ancestorLevels`	the maximum number of ancestor levels to include. A value of 0 returns no parents in the hierarchy.
	`cardinal`	`descendantLevels`	the maximum number of descendant levels to include. A value of 0 returns no children in the hierarchy.
	`boolean`	`includeSiblings`	`true` to include the siblings of the given system, `false` to omit the siblings
Return	`osid.control.SystemNode`		a system node
Errors	NOT_FOUND		`systemId` not found
	NULL_ARGUMENT		`systemId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.