<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

<!-- This component and the accompanying materials are made available under the terms of the License 

"Eclipse Public License v1.0" which accompanies this distribution, 

and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

<!-- Initial Contributors:

    Nokia Corporation - initial contribution.

Contributors: 

-->

<!DOCTYPE concept

  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

<concept id="GUID-88A5F321-17BA-566B-B025-22DB11664E54" xml:lang="en"><title>Public

and Subscribe Events for Backup and Restore</title><shortdesc> This section describes the subscribe and publish flag for backup

and restore. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section><title>Description</title><p>Applications and servers are made aware

that a backup or restore takes place through the <xref href="GUID-A81C65CF-CF4E-571C-8080-9D387F46AAD6.dita">Publish

and Subscribe</xref> (P&amp;S) events. The P&amp;S server maintains a list

of subscribers expressing an interest in the backup and restore <i>status

flag</i>. Any published changes to this flag by the Backup Engine notifies

all the subscribers. The flag provides information on whether a backup or

restore operation is in progress, whether a backup is base or incremental,

and whether the operation is full or partial.</p><p> <codeph>RProperty::Subscribe()</codeph> is

used to subscribe to a flag. The function must be used in conjunction with

an active object to be notified when the value changes. The following category

and key values must be used (defined in <codeph>epoc32\include\connect\sbdefs.h</codeph>):</p> <p>Category: <codeph>KUidSystemCategoryValue</codeph>  </p> <p>Key: <codeph>KUidBackupRestoreKey</codeph>  </p> </section>

<example><codeblock id="GUID-CA14430C-AB7C-5C65-BA41-16FD5A879F9B" xml:space="preserve">#include &lt;e32property.h&gt; 

RProperty iProperty;

iProperty.Attach(KUidSystemCategory, KUidBackupRestoreKey);

CActiveScheduler::Add(this);

iStatus = KRequestPending;

iProperty.Subscribe(iStatus);

SetActive();

// In RunL, to get the state: TInt

backupStateValue = 0;

iProperty.Get(backupStateValue);      </codeblock></example>

</conbody><related-links>

<link href="GUID-796916B2-8B23-5AD8-9DB8-8B0DA7868A62.dita"><linktext>Backup-aware

Software (Data Owner)</linktext></link>

<link href="GUID-743D2832-E73A-5184-A85D-306B2A6FFACC.dita"><linktext>Active Backup

Client</linktext></link>