org.osid.hierarchy

Interface HierarchyTraversalSession

All Superinterfaces:

java.lang.AutoCloseable, java.io.Closeable, OsidSession

public interface HierarchyTraversalSession
extends OsidSession

This session defines methods for traversing a hierarchy. Each node in the hierarchy is a unique OSID Id. The hierarchy may be traversed recursively to establish the tree structure through getParents() and getChildren(). To relate these Ids to another OSID, getNodes() can be used for retrievals that can be used for bulk lookups in other OSIDs.

Any Id available in an associated OSID is known to this hierarchy. A lookup up a particular Id in this hierarchy for the purposes of establishing a starting point for traversal or determining relationships should use the Id returned from the corresponding OSID object, not an Id that has been stored, to avoid problems with Id translation or aliasing.

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 getParents() or getChildren() in lieu of a PERMISSION_DENIED error that may disrupt the traversal through authorized pathways.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canAccessHierarchy() Tests if this user can perform hierarchy queries.
IdList	getChildren(Id id) Gets the children of the given Id.
Hierarchy	getHierarchy() Gets the hierarchy associated with this session.
Id	getHierarchyId() Gets the hierarchy Id associated with this session.
Node	getNodes(Id id, long ancestorLevels, long descendantLevels, boolean includeSiblings) Gets a portion of the hierarchy for the given Id.
IdList	getParents(Id id) Gets the parents of the given id.
IdList	getRoots() Gets the root nodes of this hierarchy.
boolean	hasChildren(Id id) Tests if this Id has any children.
boolean	hasParents(Id id) Tests if this Id contains any parents.
boolean	isAncestor(Id id, Id ancestorId) Tests if an Id is an ancestor of another.
boolean	isChild(Id id, Id childId) Tests if a node is a direct child of another.
boolean	isDescendant(Id id, Id descendantId) Tests if a node is a descendant of another.
boolean	isParent(Id id, Id parentId) Tests if an Id is a direct parent of another.

Methods inherited from interface org.osid.OsidSession

getAuthenticatedAgent, getAuthenticatedAgentId, getClockRate, getDate, getEffectiveAgent, getEffectiveAgentId, getFormatType, getLocale, isAuthenticated, startTransaction, supportsTransactions

Methods inherited from interface org.osid.binding.java.OsidSession

close

Methods inherited from interface java.io.Closeable

close

Method Detail

getHierarchyId

Id getHierarchyId()

Gets the hierarchy Id associated with this session.

Returns:

the hierarchy Id associated with this session

Compliance:

mandatory - This method must be implemented.

getHierarchy

Hierarchy getHierarchy()
                       throws OperationFailedException,
                              PermissionDeniedException

Gets the hierarchy associated with this session.

Returns:

the hierarchy associated with this session

Throws:

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

canAccessHierarchy

boolean canAccessHierarchy()

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.

Returns:

false if lookup methods are not authorized, true otherwise

Compliance:

mandatory - This method must be implemented.

getRoots

IdList getRoots()
                throws OperationFailedException,
                       PermissionDeniedException

Gets the root nodes of this hierarchy.

Returns:

the root nodes

Throws:

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

hasParents

boolean hasParents(Id id)
                   throws NotFoundException,
                          OperationFailedException,
                          PermissionDeniedException

Tests if this Id contains any parents.

Parameters:

id - the Id to query

Returns:

true if this Id contains parents, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

isParent

boolean isParent(Id id,
               Id parentId)
                 throws NotFoundException,
                        OperationFailedException,
                        PermissionDeniedException

Tests if an Id is a direct parent of another.

Parameters:

id - the Id to query

parentId - the Id of a parent

Returns:

true if this parentId is a parent of id, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id or parentId is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

Notes:

If - parentId not found return false.

getParents

IdList getParents(Id id)
                  throws NotFoundException,
                         OperationFailedException,
                         PermissionDeniedException

Gets the parents of the given id.

Parameters:

id - the Id to query

Returns:

the parents of the id

Throws:

NotFoundException - id is not found

NullArgumentException - id is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

isAncestor

boolean isAncestor(Id id,
                 Id ancestorId)
                   throws NotFoundException,
                          OperationFailedException,
                          PermissionDeniedException

Tests if an Id is an ancestor of another.

Parameters:

id - the Id to query

ancestorId - the Id of an ancestor

Returns:

true if this ancestorId is a parent of id, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id or ancestorId is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

Notes:

If - ancestorId not found return false.

hasChildren

boolean hasChildren(Id id)
                    throws NotFoundException,
                           OperationFailedException,
                           PermissionDeniedException

Tests if this Id has any children.

Parameters:

id - the Id to query

Returns:

true if this Id has children, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

isChild

boolean isChild(Id id,
              Id childId)
                throws NotFoundException,
                       OperationFailedException,
                       PermissionDeniedException

Tests if a node is a direct child of another.

Parameters:

id - the Id to query

childId - the Id of a child

Returns:

true if this childId is a child of the Id, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id or childId is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

Notes:

If - childId not found return false.

getChildren

IdList getChildren(Id id)
                   throws NotFoundException,
                          OperationFailedException,
                          PermissionDeniedException

Gets the children of the given Id.

Parameters:

id - the Id to query

Returns:

the children of the id

Throws:

NotFoundException - id is not found

NullArgumentException - id is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

isDescendant

boolean isDescendant(Id id,
                   Id descendantId)
                     throws NotFoundException,
                            OperationFailedException,
                            PermissionDeniedException

Tests if a node is a descendant of another.

Parameters:

id - the Id to query

descendantId - the Id of a descendant

Returns:

true if this descendantId is a child of the Id, false otherwise

Throws:

NotFoundException - id is not found

NullArgumentException - id or descendant is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.

Notes:

If - not found return false.

getNodes

Node getNodes(Id id,
            long ancestorLevels,
            long descendantLevels,
            boolean includeSiblings)
              throws NotFoundException,
                     OperationFailedException,
                     PermissionDeniedException

Gets a portion of the hierarchy for the given Id.

Parameters:

id - the Id to query

ancestorLevels - the maximum number of ancestor levels to include. A value of 0 returns no parents in the node.

descendantLevels - the maximum number of descendant levels to include. A value of 0 returns no children in the node.

includeSiblings - true to include the siblings of the given node, false to omit the siblings

Returns:

a node

Throws:

NotFoundException - id is not found

NullArgumentException - id is null

OperationFailedException - unable to complete request

PermissionDeniedException - authorization failure

Compliance:

mandatory - This method must be implemented.