com.sap.portal.admin.editor

Interface ILockingPolicy

All Known Subinterfaces:

IPessimisticLockPolicy

Deprecated. As of SAP NetWeaver 2007 release, replaced by package com.sap.portal.adminstudio.ilockingpolicy

public interface ILockingPolicy

The interface that represents the locking policy of an editor.
Editor locking is the mechanism that deals with the issues of a multi-user environment. In this environment, multiple users can work on the same resource simultaneously. If there is no mechanism to manage the data, a user might work with non-updated data, since the user's editor state is not synchronized with the current sate of the resource.
There are two approaches to locking.

• Pessimistic Locking: The resource that the user works on is locked immediately when it is retrieved. The user can edit the data. If another user tries to load the same resource, it is available as read-only. This approach requires the resources to support a method for locking. PCM objects support pessimistic locking.
• Optimistic Locking: The resource is not immediately locked, but when a resource is retrieved a special attribute of the resource version is also supplied. This version is held by the editor until a save operation. Then the editor compares the version that it holds to the current version in the persistence layer. If they don't match, it indicates that the resource has meanwhile been changed by another user and the save operation fails. Otherwise, it saves the updated resource, and gives the version a newer value. PCM objects currently do not support optimistic locking, and this approach is not used in EP 6.0.

The editor framework provides a default implementation of pessimistic locking for PCM objects. No action is required to use this methodology.
The following lock statuses are available:
• NEW_LOCK: The resource is locked with a new lock. The editor framework registers this lock, and the editor is opened for editing (if no other veto is raised)
• EXISTING_LOCK: The resource is already locked by this user and session so it requires no special treatment. The editor is opened for editing (if no other veto is raised). Registration is not required.
• RESOURCE_IS_LOCKED: The resource is locked by another entity. The editor framework opens the editor in read-only mode, and an end-user message is presented.
• RESOURCE_IN_HOLD: The resource is locked. However, the resource can be taken if the current user requests. The editor framework presents a question, and if the user chooses yes, to enforce the lock, the editor framework calls the getLock method using the enforce parameter.

Method Summary

EditorLockingStatus

getLock(IEditorContext context, com.sap.security.api.IPrincipal principal, boolean enforce, PPLogger logger) Deprecated. Gets the lock for the specified editor.

Method Detail

getLock

EditorLockingStatus getLock(IEditorContext context,
                            com.sap.security.api.IPrincipal principal,
                            boolean enforce,
                            PPLogger logger)
                            throws EditorLockingException,
                                   EditorResourceException

Deprecated.

Gets the lock for the specified editor.
The editor framework maintains the locking flow, according to the status returned.

Parameters:

context - the current context of the editor

principal - a security principal trying to get the lock

enforce - indicates whether to get a new lock, even if the resource is already locked

logger - to log messages

Returns:

EditorLockingStatus the lock status

Throws:

EditorLockingException - if getting a lock fails

EditorResourceException - if an error occurs regarding the resource that this editor deals with, and an error message is displayed instead of the regular editor user interface

See Also:

EditorLockingStatus

Access Rights

This class can be accessed from:

SC	DC	Public Part	ACH
[sap.com] EP-RUNTIME	[sap.com] tc/ep/admin/api	api	EP-PIN