1 files changed, 23 insertions, 2 deletions
diff --git a/bundles/org.eclipse.equinox.preferences/schema/preferences.exsd b/bundles/org.eclipse.equinox.preferences/schema/preferences.exsd
index 6173800bc..3f2531436 100644
--- a/bundles/org.eclipse.equinox.preferences/schema/preferences.exsd
+++ b/bundles/org.eclipse.equinox.preferences/schema/preferences.exsd
@@ -63,7 +63,7 @@
                </documentation>
             </annotation>
          </attribute>
-         <attribute name="class" type="string" use="required">
+         <attribute name="class" type="string">
             <annotation>
                <documentation>
                   The name of the class.
@@ -73,6 +73,16 @@
                </appInfo>
             </annotation>
          </attribute>
+         <attribute name="storage" type="string">
+            <annotation>
+               <documentation>
+                  The class which implements the preference storage.
+               </documentation>
+               <appInfo>
+                  <meta.attribute kind="java" basedOn="org.eclipse.core.runtime.preferences.AbstractPreferenceStorage:"/>
+               </appInfo>
+            </annotation>
+         </attribute>
       </complexType>
    </element>
 
@@ -140,6 +150,17 @@
       &lt;/extension&gt;
    &lt;/pre&gt;
 &lt;/p&gt;
+
+If the client chooses let the Eclipse Platform handle the preference nodes but wishes to define a custom location/mechanism for persisting the data, then they are able to set the &quot;storage&quot; attribute on the &quot;scope&quot; element. Note that only one of the &quot;class&quot; and &quot;storage&quot; attributes can be defined at the same time. The class referenced in the &quot;storage&quot; attribute must extend the AbstractPreferenceStorage class. In the following example the &quot;FooStorage&quot; class handles the loading/saving for the &quot;foo&quot; preferences.
+&lt;p&gt;
+   &lt;pre&gt;
+      &lt;extension point=&quot;org.eclipse.equinox.preferences.preferences&quot;&gt;
+         &lt;scope name=&quot;foo&quot; storage=&quot;com.example.FooStorage&quot;/&gt;
+         &lt;initializer class=&quot;com.example.MyPreferenceInitializer&quot;/&gt;
+         &lt;modifier class=&quot;com.example.MyModifyListener&quot;/&gt;
+      &lt;/extension&gt;
+   &lt;/pre&gt;
+&lt;/p&gt;
       </documentation>
    </annotation>
 
@@ -166,7 +187,7 @@
          <meta.section type="copyright"/>
       </appInfo>
       <documentation>
-         Copyright (c) 2004, 2009 IBM Corporation and others.&lt;br&gt;
+         Copyright (c) 2004, 2012 IBM Corporation and others.&lt;br&gt;
 All rights reserved. This program and the accompanying materials are made 
 available under the terms of the Eclipse Public License v1.0 which 
 accompanies this distribution, and is available at