diff -r 1f48f3eff75f openide.nodes/apichanges.xml
--- a/openide.nodes/apichanges.xml	Wed Sep 01 18:31:09 2010 +0200
+++ b/openide.nodes/apichanges.xml	Thu Sep 02 18:43:18 2010 +0200
@@ -49,6 +49,23 @@
 <apidef name="nodes">Nodes API</apidef>
 </apidefs>
 <changes>
+    <change id="Node.updateChildren">
+        <api name="nodes"/>
+        <summary>A mechanism to lazily update node's children.</summary>
+        <version major="7" minor="18"/>
+        <date day="9" month="9" year="2010"/>
+        <author login="mentlicher"/>
+        <compatibility addition="yes" binary="compatible" source="compatible" semantic="compatible"/>
+        <description>
+            <p>
+            <a href="@TOP@/org/openide/nodes/Node.html">Node</a> has a new updateChildren()
+            protected method, that can be overriden to provide Children implementation
+            when node's children are needed.
+            </p>
+        </description>
+        <class package="org.openide.nodes" name="Node"/>
+        <issue number="190115"/>
+    </change>
     <change id="IndexedNode.LookupConstr">
         <api name="nodes"/>
         <summary>New constructor of IndexedNode</summary>
diff -r 1f48f3eff75f openide.nodes/manifest.mf
--- a/openide.nodes/manifest.mf	Wed Sep 01 18:31:09 2010 +0200
+++ b/openide.nodes/manifest.mf	Thu Sep 02 18:43:18 2010 +0200
@@ -2,5 +2,5 @@
 OpenIDE-Module: org.openide.nodes
 OpenIDE-Module-Localizing-Bundle: org/openide/nodes/Bundle.properties
 AutoUpdate-Essential-Module: true
-OpenIDE-Module-Specification-Version: 7.17
+OpenIDE-Module-Specification-Version: 7.18
 
diff -r 1f48f3eff75f openide.nodes/src/org/openide/nodes/FilterNode.java
--- a/openide.nodes/src/org/openide/nodes/FilterNode.java	Wed Sep 01 18:31:09 2010 +0200
+++ b/openide.nodes/src/org/openide/nodes/FilterNode.java	Thu Sep 02 18:43:18 2010 +0200
@@ -1049,7 +1049,7 @@
      * setChildren will fire the appropriate events
      */
     @Override
-    final void updateChildren() {
+    protected final org.openide.nodes.Children updateChildren(org.openide.nodes.Children origChildren) {
         if (isDefault()) {
             org.openide.nodes.Children newChildren = null;
 
@@ -1066,16 +1066,10 @@
             }
 
             if (newChildren != null) {
-                final org.openide.nodes.Children set = newChildren;
-                Children.MUTEX.postWriteRequest(
-                    new Runnable() {
-                        public void run() {
-                            setChildren(set);
-                        }
-                    }
-                );
+                return newChildren;
             }
         }
+        return origChildren;
     }
 
     /** An exception to be thrown from hashCode() to debug issue 46993.
diff -r 1f48f3eff75f openide.nodes/src/org/openide/nodes/Node.java
--- a/openide.nodes/src/org/openide/nodes/Node.java	Wed Sep 01 18:31:09 2010 +0200
+++ b/openide.nodes/src/org/openide/nodes/Node.java	Thu Sep 02 18:43:18 2010 +0200
@@ -461,10 +461,32 @@
         return hierarchy;
     }
 
-    /** Can be overridden in subclasses (probably in FilterNode) to check
+    /** Can be called in subclasses (probably in FilterNode) to check
      * whether children are of the right subclass
      */
-    void updateChildren() {
+    final void updateChildren() {
+        Children origChildren = hierarchy;
+        final Children newChildren = updateChildren(origChildren);
+        if (newChildren != origChildren && newChildren != null) {
+            Children.MUTEX.postWriteRequest(
+                new Runnable() {
+                    public void run() {
+                        setChildren(newChildren);
+                    }
+                }
+            );
+        }
+    }
+
+    /**
+     * Can be overridden in subclasses to update the children of this node
+     * when someone asks for them.
+     * @param origChildren Original Children passed to the constructor.
+     * @return Children instance to be used instead of the original.
+     * @since 7.18
+     */
+    protected Children updateChildren(Children origChildren) {
+        return origChildren;
     }
 
     /** Allows to change Children of the node. Call to this method aquires
diff -r 1f48f3eff75f openide.nodes/test/unit/src/org/openide/nodes/SetChildrenTest.java
--- a/openide.nodes/test/unit/src/org/openide/nodes/SetChildrenTest.java	Wed Sep 01 18:31:09 2010 +0200
+++ b/openide.nodes/test/unit/src/org/openide/nodes/SetChildrenTest.java	Thu Sep 02 18:43:18 2010 +0200
@@ -261,6 +261,15 @@
         
         GoldenEvent.assertEvents ( nl.getEvents(), goldenEvents, PropertyChangeEvent.class );        
     }
+
+    /** Test whether updateChildren() is called and children are updated
+     */
+    public void testUpdateChildren() {
+        TestNodeUCh n = new TestNodeUCh(Children.LEAF);
+        assertSame("Children not updated", n.newChildren, n.getChildren());
+        n = new TestNodeUCh(Children.LEAF);
+        assertFalse("Children not updated, the node should not be leaf", n.isLeaf());
+    }
     
     
     /** Tests property changes on old and new nodes
@@ -290,6 +299,26 @@
         }        
     }
     
+    private static class TestNodeUCh extends AbstractNode {
+
+        private Children origChildren;
+        Children newChildren = new Children.Array();
+
+        public TestNodeUCh( Children ch ) {
+            super( ch );
+            origChildren = ch;
+        }
+
+        @Override
+        protected Children updateChildren(Children origChildren) {
+            if (origChildren == this.origChildren) {
+                return newChildren;
+            }
+            return origChildren;
+        }
+
+    }
+
     /** Useful class for testing events.
      */