implemented the initial XML-RPC APIs in Venice - for creating and destroying

"sessions," logging in, posting messages to topics, attaching files to
messages, and a couple of minor things that aren't as important right now

etc/ui-config.xml

@@ -276,19 +276,58 @@
 
   <!-- Configuration for the RPC interfaces. -->
   <rpc>
+    <!-- Timeout for RPC sessions -->
+    <session-timeout>60</session-timeout>
+
     <xmlrpc-methods>
       <!-- XML-RPC validation suite -->
-      <method name="validator1\.[a-zA-Z]*"><script name="test/validation.js"/></method>
+      <method name="validator1\.[:alpha:]+"><script name="test/validation.js"/></method>
 
       <!-- Multicall "boxcar" marshaller (see http://www.xmlrpc.com/discuss/msgReader$1208) -->
       <method name="system.multicall"><object class="com.silverwrist.venice.ui.rpc.XmlRpcMulticall"/></method>
 
+      <!-- The session creation API -->
+      <method name="venice:session\.create">
+        <object class="com.silverwrist.venice.ui.rpc.XmlRpcCreateSession"/>
+      </method>
+
+      <!-- The other session APIs -->
+      <method name="venice:session\.([:alnum:]+)">
+        <script name="session.js"/>
+	<session param="0"/>
+        <env name="call" value="${match.1}"/>
+      </method>
+
+      <!-- The conferencing APIs for conferences -->
+      <method name="venice:conferencing\.conference\.([:alnum:]+)">
+	<script name="conf/conference.js"/>
+	<session param="0"/>
+        <env name="call" value="${match.1}"/>
+      </method>
+      
+      <!-- The conferencing APIs for topics -->
+      <method name="venice:conferencing\.topic\.([:alnum:]+)">
+	<script name="conf/topic.js"/>
+	<session param="0"/>
+        <env name="call" value="${match.1}"/>
+      </method>
+
+      <!-- The conferencing APIs for messages -->
+      <method name="venice:conferencing\.message\.([:alnum:]+)">
+	<script name="conf/message.js"/>
+	<session param="0"/>
+        <env name="call" value="${match.1}"/>
+      </method>
+
+      <!-- A test method -->
       <method name="venice:test\.sumDifference">
         <!-- <object class="com.silverwrist.venice.ui.rpc.XmlRpcTestHandler"/> -->
+        <!-- <session param="0"/> -->
         <script name="test/test1.js"/>
         <env name="e1" value="foo"/>
 	<env name="p1" value="${param.0}"/>
       </method>
+
     </xmlrpc-methods>
   </rpc>
 

rpcscripts/conf/conference.js

@@ -0,0 +1,59 @@
+// The contents of this file are subject to the Mozilla Public License Version 1.1
+// (the "License"); you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+// 
+// Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+// WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+// language governing rights and limitations under the License.
+// 
+// The Original Code is the Venice Web Communities System.
+// 
+// The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+// for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+// Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+// 
+// Contributor(s): 
+
+// Implements the conferencing topic API
+
+importPackage(java.util);
+importPackage(Packages.com.silverwrist.venice.core);
+importPackage(Packages.com.silverwrist.venice.ui.rpc);
+
+rinput = bsf.lookupBean("request");
+xreq = bsf.lookupBean("xmlrpc");
+env = bsf.lookupBean("environment");
+call_name = env.get("call");
+
+// All methods have at least three parameters: session, community, conference.
+if (xreq.paramCount<3)
+{ // not enough parameters
+  vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  vlib.done();
+
+} // end if
+
+comm = xreq.getParamCommunity(1);
+conf = xreq.getParamConference(2,comm);
+
+if ("name"==call_name)
+{ // venice:conferencing.conference.name <session-id> <community> <conference> [<new-name>]
+  // Retrieves or sets the conference name.
+  if (xreq.paramCount==3)
+    vlib.output(conf.name);
+  else if (xreq.paramCount==4)
+  { // set the name
+    name = xreq.getParamString(3);
+    conf.name = name;
+    vlib.output(name);  // output the new name on success
+
+  } // end else if
+  else  // wrong parameter count
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+
+  vlib.done();
+    
+} // end if
+
+// just in case there's a method name that wasn't listed
+vlib.output(new XmlRpcFault(XmlRpcFault.METHOD_NOT_FOUND,"invalid method name: " + xreq.method));

rpcscripts/conf/message.js

@@ -0,0 +1,60 @@
+// The contents of this file are subject to the Mozilla Public License Version 1.1
+// (the "License"); you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+// 
+// Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+// WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+// language governing rights and limitations under the License.
+// 
+// The Original Code is the Venice Web Communities System.
+// 
+// The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+// for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+// Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+// 
+// Contributor(s): 
+
+// Implements the conferencing message API
+
+importPackage(java.util);
+importPackage(Packages.com.silverwrist.venice.core);
+importPackage(Packages.com.silverwrist.venice.ui.rpc);
+
+rinput = bsf.lookupBean("request");
+xreq = bsf.lookupBean("xmlrpc");
+env = bsf.lookupBean("environment");
+call_name = env.get("call");
+
+// All methods have at least five parameters: session, community, conference, topic, message.
+if (xreq.paramCount<5)
+{ // not enough parameters
+  vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  vlib.done();
+
+} // end if
+
+comm = xreq.getParamCommunity(1);
+conf = xreq.getParamConference(2,comm);
+topic = xreq.getParamTopic(3,conf);
+msg = xreq.getParamPost(4,topic);
+
+if ("attach"==call_name)
+{ // venice:conferencing.message.attach <session-id> <community> <conference> <topic> <message> <mime-type>
+  //                                    <filename> <data>
+  if (xreq.paramCount!=8)
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  else if ("base64"!=xreq.getParamType(7))
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"data parameter type mismatch"));
+  else
+  { // attach the data and return
+    msg.attachData(xreq.getParamString(5),xreq.getParamString(6),vlib.castByteArray(xreq.getParam(7)));
+    vlib.output(vlib.booleanObject(true));
+
+  } // end else
+
+  vlib.done();
+
+} // end if
+
+// just in case there's a method name that wasn't listed
+vlib.output(new XmlRpcFault(XmlRpcFault.METHOD_NOT_FOUND,"invalid method name: " + xreq.method));

rpcscripts/conf/topic.js

@@ -0,0 +1,57 @@
+// The contents of this file are subject to the Mozilla Public License Version 1.1
+// (the "License"); you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+// 
+// Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+// WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+// language governing rights and limitations under the License.
+// 
+// The Original Code is the Venice Web Communities System.
+// 
+// The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+// for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+// Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+// 
+// Contributor(s): 
+
+// Implements the conferencing topic API
+
+importPackage(java.util);
+importPackage(Packages.com.silverwrist.venice.core);
+importPackage(Packages.com.silverwrist.venice.ui.rpc);
+
+rinput = bsf.lookupBean("request");
+xreq = bsf.lookupBean("xmlrpc");
+env = bsf.lookupBean("environment");
+call_name = env.get("call");
+
+// All methods have at least four parameters: session, community, conference, topic.
+if (xreq.paramCount<4)
+{ // not enough parameters
+  vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  vlib.done();
+
+} // end if
+
+comm = xreq.getParamCommunity(1);
+conf = xreq.getParamConference(2,comm);
+topic = xreq.getParamTopic(3,conf);
+
+if ("postMessage"==call_name)
+{ // venice:conferencing.topic.postMessage <session-id> <community> <conference> <topic> <pseud> <text>
+  // Posts a message, returns the message number within the topic
+  if (xreq.paramCount!=6)
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  else
+  { // post the message
+    msg = topic.postNewMessage(0,xreq.getParamString(4),xreq.getParamString(5));
+    vlib.output(vlib.createInteger(msg.postNumber));
+
+  } // end else
+
+  vlib.done();
+
+} // end if
+
+// just in case there's a method name that wasn't listed
+vlib.output(new XmlRpcFault(XmlRpcFault.METHOD_NOT_FOUND,"invalid method name: " + xreq.method));

rpcscripts/session.js

@@ -0,0 +1,66 @@
+// The contents of this file are subject to the Mozilla Public License Version 1.1
+// (the "License"); you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+// 
+// Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+// WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+// language governing rights and limitations under the License.
+// 
+// The Original Code is the Venice Web Communities System.
+// 
+// The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+// for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+// Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+// 
+// Contributor(s): 
+
+// Implements the session API
+
+importPackage(java.util);
+importPackage(Packages.com.silverwrist.venice.core);
+importPackage(Packages.com.silverwrist.venice.ui.rpc);
+
+rinput = bsf.lookupBean("request");
+xreq = bsf.lookupBean("xmlrpc");
+env = bsf.lookupBean("environment");
+call_name = env.get("call");
+//logger.debug("call selector = " + call_name);
+
+if ("destroy"==call_name)
+{ // venice:session.destroy <session-id> - destroys a session
+  if (xreq.paramCount!=1)
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  else
+  { // end the session
+    rinput.endSession();
+    vlib.output(vlib.booleanObject(true));
+
+  } // end else
+
+  vlib.done();
+  
+} // end if
+
+if ("login"==call_name)
+{ // venice:session.login <session-id> <username> <password> - logs in the session
+  if (xreq.paramCount!=3)
+    vlib.output(new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter count mismatch"));
+  else
+  { // get the user name and password and log in
+    username = xreq.getParamString(1);
+    password = xreq.getParamString(2);
+
+    if (rinput.user.isLoggedIn())
+      vlib.output(new XmlRpcFault(XmlRpcFault.DEFAULT_ERROR,"user already logged in"));
+    else
+      rinput.user.authenticate(username,password);
+    vlib.output(vlib.booleanObject(true));
+
+  } // end else
+
+  vlib.done();
+
+} // end if
+
+// just in case there's a method name that wasn't listed
+vlib.output(new XmlRpcFault(XmlRpcFault.METHOD_NOT_FOUND,"invalid method name: " + xreq.method));

src/com/silverwrist/venice/core/TopicMessageContext.java

@@ -75,6 +75,8 @@ public interface TopicMessageContext
   public abstract void attachData(String m_type, String file, int length, InputStream data)
       throws AccessError, DataException;
 
+  public abstract void attachData(String m_type, String file, byte[] data) throws AccessError, DataException;
+
   public abstract boolean canPublish();
 
   public abstract void publish() throws DataException, AccessError;

src/com/silverwrist/venice/core/impl/TopicMessageUserContextImpl.java

@@ -923,6 +923,12 @@ class TopicMessageUserContextImpl implements TopicMessageContext
 
   } // end attachData
 
+  public void attachData(String m_type, String file, byte[] data) throws AccessError, DataException
+  {
+    attachData(m_type,file,data.length,new ByteArrayInputStream(data));
+
+  } // end attachData
+
   public boolean canPublish()
   {
     if (!(env.testPermission(EnvUser.PERM_PUBLISH_FP)))

src/com/silverwrist/venice/except/AccessError.java

@@ -11,7 +11,7 @@
  * 
  * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
  * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
- * Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * Copyright (C) 2001-02 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
  * 
  * Contributor(s): 
  */
@@ -19,6 +19,18 @@ package com.silverwrist.venice.except;
 
 public class AccessError extends VeniceException
 {
+  /*--------------------------------------------------------------------------------
+   * Static data members
+   *--------------------------------------------------------------------------------
+   */
+
+  private static final int FAULTCODE_BASE = 20000;
+
+  /*--------------------------------------------------------------------------------
+   * Constructors
+   *--------------------------------------------------------------------------------
+   */
+
   public AccessError()
   {
     super();
@@ -43,4 +55,15 @@ public class AccessError extends VeniceException
 
   } // end constructor
   
+  /*--------------------------------------------------------------------------------
+   * Overrides from class VeniceException
+   *--------------------------------------------------------------------------------
+   */
+
+  public int getFaultCode()
+  {
+    return FAULTCODE_BASE;
+
+  } // end getFaultCode
+
 } // end class AccessError

src/com/silverwrist/venice/except/DataException.java

@@ -11,7 +11,7 @@
  * 
  * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
  * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
- * Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * Copyright (C) 2001-02 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
  * 
  * Contributor(s): 
  */
@@ -19,6 +19,18 @@ package com.silverwrist.venice.except;
 
 public class DataException extends VeniceException
 {
+  /*--------------------------------------------------------------------------------
+   * Static data members
+   *--------------------------------------------------------------------------------
+   */
+
+  private static final int FAULTCODE_BASE = 10000;
+
+  /*--------------------------------------------------------------------------------
+   * Constructors
+   *--------------------------------------------------------------------------------
+   */
+
   public DataException()
   {
     super();
@@ -43,4 +55,15 @@ public class DataException extends VeniceException
 
   } // end constructor
 
+  /*--------------------------------------------------------------------------------
+   * Overrides from class VeniceException
+   *--------------------------------------------------------------------------------
+   */
+
+  public int getFaultCode()
+  {
+    return FAULTCODE_BASE;
+
+  } // end getFaultCode
+
 } // end class DataException

src/com/silverwrist/venice/except/SupplyFaultCode.java

@@ -0,0 +1,24 @@
+/*
+ * The contents of this file are subject to the Mozilla Public License Version 1.1
+ * (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+ * 
+ * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+ * WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+ * language governing rights and limitations under the License.
+ * 
+ * The Original Code is the Venice Web Communities System.
+ * 
+ * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+ * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+ * Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * 
+ * Contributor(s): 
+ */
+package com.silverwrist.venice.except;
+
+public interface SupplyFaultCode
+{
+  public abstract int getFaultCode();
+
+} // end interface SupplyFaultCode

src/com/silverwrist/venice/except/VeniceException.java

@@ -11,7 +11,7 @@
  * 
  * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
  * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
- * Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * Copyright (C) 2001-02 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
  * 
  * Contributor(s): 
  */
@@ -27,7 +27,7 @@ import java.io.PrintWriter;
  * @author Eric J. Bowersox &lt;erbo@silcom.com&gt;
  * @version X
  */
-public class VeniceException extends Exception
+public class VeniceException extends Exception implements SupplyFaultCode
 {
   /*--------------------------------------------------------------------------------
    * Attributes
@@ -139,6 +139,17 @@ public class VeniceException extends Exception
 
   } // end printStackTrace
 
+  /*--------------------------------------------------------------------------------
+   * Implementations from interface SupplyFaultCode
+   *--------------------------------------------------------------------------------
+   */
+
+  public int getFaultCode()
+  {
+    return 0;
+
+  } // end getFaultCode
+
   /*--------------------------------------------------------------------------------
    * External operations
    *--------------------------------------------------------------------------------

src/com/silverwrist/venice/ui/RequestInput.java

@@ -188,4 +188,8 @@ public interface RequestInput extends LinkTypes
 
   public abstract void registerCleanup(AutoCleanup ac);
 
+  public abstract void pushSession(VeniceUISession sess);
+
+  public abstract void popSession();
+
 } // end interface RequestInput

src/com/silverwrist/venice/ui/config/RootConfig.java

@@ -81,6 +81,7 @@ public class RootConfig implements LinkTypes, ColorSelectors
   private ButtonHolder buttons;            // the button definitions
   private String[] content_hdr;            // the content header parts
   private Remapper remapper;               // the URL remapper
+  private int rpc_timeout = 60;            // RPC session timeout
   private List xmlrpc_methods;             // the list of XML-RPC methods
   private StockMessages stock_messages;    // the stock messages
   private Map menus;                       // the menus
@@ -391,6 +392,18 @@ public class RootConfig implements LinkTypes, ColorSelectors
     sect = loader.configGetSubSection(root_h,"rpc");
     sect_h = new DOMElementHelper(sect);
 
+    // Get the <session-timeout/> figure.
+    if (sect_h.hasChildElement("session-timeout"))
+    { // get the timeout value
+      Integer xtmp = sect_h.getSubElementInt("session-timeout");
+      if (xtmp==null)
+	throw new ConfigException("<session-timeout/> value is not an integer",sect);
+      rpc_timeout = xtmp.intValue();
+      if (rpc_timeout<=0)
+	throw new ConfigException("<session-timeout/> value is invalid",sect);
+
+    } // end if
+
     // Get the <xmlrpc-methods/> section.
     sect1 = loader.configGetSubSection(sect_h,"xmlrpc-methods");
     nl = sect1.getChildNodes();
@@ -773,6 +786,12 @@ public class RootConfig implements LinkTypes, ColorSelectors
 
   } // end getDefaultServletAddress
 
+  public final int getRpcSessionTimeout()
+  {
+    return rpc_timeout;
+
+  } // end getRpcSessionTimeout
+
   public final List getXmlRpcMethods()
   {
     return xmlrpc_methods;

src/com/silverwrist/venice/ui/rpc/RpcSessionBroker.java

@@ -0,0 +1,203 @@
+/*
+ * The contents of this file are subject to the Mozilla Public License Version 1.1
+ * (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+ * 
+ * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+ * WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+ * language governing rights and limitations under the License.
+ * 
+ * The Original Code is the Venice Web Communities System.
+ * 
+ * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+ * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+ * Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * 
+ * Contributor(s): 
+ */
+package com.silverwrist.venice.ui.rpc;
+
+import java.util.*;
+import javax.servlet.*;
+import org.apache.log4j.*;
+import com.silverwrist.venice.core.*;
+import com.silverwrist.venice.except.*;
+import com.silverwrist.venice.ui.*;
+import com.silverwrist.venice.ui.config.RootConfig;
+import com.silverwrist.venice.ui.servlet.RequestImpl;
+
+class RpcSessionBroker
+{
+  /*--------------------------------------------------------------------------------
+   * Internal class for sweeping the sessions
+   *--------------------------------------------------------------------------------
+   */
+
+  class SessionSweeper extends TimerTask
+  {
+    private LinkedList workspace = new LinkedList();
+
+    SessionSweeper()
+    {
+      super();
+
+    } // end constructor
+
+    public void run()
+    {
+      synchronized (RpcSessionBroker.this)
+      { // seek and destroy all expired sessions
+	Iterator it = sessions.values().iterator();
+	while (it.hasNext())
+	{ // find all the tasks that are due to be invalidated
+	  RpcVeniceUISession s = (RpcVeniceUISession)(it.next());
+	  if (s.canUnloadNow())
+	    workspace.addLast(s);
+
+	} // end while
+
+	while (workspace.size()>0)
+	{ // invalidate all sessions that have not been accessed recently
+	  RpcVeniceUISession s = (RpcVeniceUISession)(workspace.removeFirst());
+	  if (logger.isDebugEnabled())
+	    logger.debug("session sweeper removing session with ID " + s.getID());
+	  s.invalidate();
+
+	} // end while
+
+      } // end synchronized block
+
+    } // end run
+
+  } // end class SessionSweeper
+
+  /*--------------------------------------------------------------------------------
+   * Static data members
+   *--------------------------------------------------------------------------------
+   */
+
+  private static Category logger = Category.getInstance(RpcSessionBroker.class);
+
+  private static final String ATTRIBUTE = "ui.rpc.SessionBroker";
+
+  private static final long INTERVAL = 1000;
+
+  private static final String PREFIX = "rpcsess:";
+  private static final String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
+  private static final int ID_LENGTH = 40;
+
+  private static Random rng = new Random();  // random number generator
+
+  /*--------------------------------------------------------------------------------
+   * Attributes
+   *--------------------------------------------------------------------------------
+   */
+
+  private HashMap sessions = new HashMap();  // the actual sessions
+  private VeniceEngine engine;               // the Venice engine
+  private int timeout_value;                 // the timeout value
+  private Timer timer = new Timer(true);     // the interval timer used to schedule sweeps
+
+  /*--------------------------------------------------------------------------------
+   * Constructor
+   *--------------------------------------------------------------------------------
+   */
+
+  private RpcSessionBroker(VeniceEngine engine, RootConfig root)
+  {
+    this.engine = engine;
+    this.timeout_value = root.getRpcSessionTimeout();
+    timer.scheduleAtFixedRate(new SessionSweeper(),INTERVAL,INTERVAL);
+
+  } // end constructor
+
+  /*--------------------------------------------------------------------------------
+   * Internal operations
+   *--------------------------------------------------------------------------------
+   */
+
+  private static final String generateID()
+  {
+    StringBuffer buf = new StringBuffer(PREFIX);
+    for (int i=0; i<ID_LENGTH; i++)
+      buf.append(ALPHABET.charAt(rng.nextInt(ALPHABET.length())));
+    return buf.toString();
+
+  } // end generateID
+
+  /*--------------------------------------------------------------------------------
+   * External operations
+   *--------------------------------------------------------------------------------
+   */
+
+  final int getTimeout()
+  {
+    return timeout_value;
+
+  } // end getTimeout
+
+  final VeniceEngine getEngine()
+  {
+    return engine;
+
+  } // end getEngine
+
+  final synchronized VeniceUISession getSession(String id)
+  {
+    if (logger.isDebugEnabled())
+      logger.debug("looking up session with ID " + id + " - current session count is " + sessions.size());
+    RpcVeniceUISession rc = (RpcVeniceUISession)(sessions.get(id));
+    if (rc!=null)
+      rc.touch();
+    return rc;
+
+  } // end getSession
+
+  final synchronized VeniceUISession createSession(String remote_address) throws DataException
+  {
+    String new_id = generateID();
+    while (sessions.containsKey(new_id))
+      new_id = generateID();
+    RpcVeniceUISession rc = new RpcVeniceUISession(new_id,remote_address,this);
+    sessions.put(new_id,rc);
+    if (logger.isDebugEnabled())
+      logger.debug("created new session with ID " + new_id + " - session count now " + sessions.size());
+    return rc;
+
+  } // end createSession
+
+  final synchronized void detachSession(String id)
+  {
+    if (logger.isDebugEnabled())
+      logger.debug("removing session with ID " + id + " - current session count is " + sessions.size());
+    sessions.remove(id);
+    if (logger.isDebugEnabled())
+      logger.debug("session count now " + sessions.size());
+
+  } // end detachSession
+
+  /*--------------------------------------------------------------------------------
+   * External static operations
+   *--------------------------------------------------------------------------------
+   */
+
+  public static RpcSessionBroker get(ServletContext ctxt)
+  {
+    return (RpcSessionBroker)(RequestImpl.getAppAttribute(ctxt,ATTRIBUTE));
+
+  } // end get
+
+  public static RpcSessionBroker get(RequestInput ri)
+  {
+    return (RpcSessionBroker)(ri.getAppAttribute(ATTRIBUTE));
+
+  } // end get
+
+  public static synchronized void init(ServletContext ctxt, VeniceEngine engine, RootConfig root)
+  {
+    if (RequestImpl.getAppAttribute(ctxt,ATTRIBUTE)==null)
+      RequestImpl.setAppAttribute(ctxt,ATTRIBUTE,new RpcSessionBroker(engine,root));
+
+  } // end init
+
+} // end class RpcSessionBroker

src/com/silverwrist/venice/ui/rpc/RpcVeniceUISession.java

@@ -0,0 +1,161 @@
+/*
+ * The contents of this file are subject to the Mozilla Public License Version 1.1
+ * (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+ * 
+ * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+ * WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+ * language governing rights and limitations under the License.
+ * 
+ * The Original Code is the Venice Web Communities System.
+ * 
+ * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+ * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+ * Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * 
+ * Contributor(s): 
+ */
+package com.silverwrist.venice.ui.rpc;
+
+import java.util.*;
+import com.silverwrist.venice.core.*;
+import com.silverwrist.venice.except.*;
+import com.silverwrist.venice.ui.*;
+
+class RpcVeniceUISession implements VeniceUISession
+{
+  /*--------------------------------------------------------------------------------
+   * Attributes
+   *--------------------------------------------------------------------------------
+   */
+
+  private RpcSessionBroker broker;        // session broker
+  private long create_time;               // session creation time
+  private long access_time;               // session last access time
+  private String id;                      // the session ID
+  private String remote_addr;             // the remote address
+  private int max_inactive;               // the maximum inactive interval
+  private HashMap attrs = new HashMap();  // storage for attributes
+  private UserContext user;               // user context in this session
+
+  /*--------------------------------------------------------------------------------
+   * Constructor
+   *--------------------------------------------------------------------------------
+   */
+
+  RpcVeniceUISession(String id, String remote_addr, RpcSessionBroker broker) throws DataException
+  {
+    this.broker = broker;
+    this.id = id;
+    this.remote_addr = remote_addr;
+    this.max_inactive = broker.getTimeout() * 60;
+    this.user = broker.getEngine().createUserContext(remote_addr);
+    this.create_time = this.access_time = System.currentTimeMillis();
+
+  } // end constructor
+
+  /*--------------------------------------------------------------------------------
+   * Implementations from interface VeniceUISession
+   *--------------------------------------------------------------------------------
+   */
+
+  public long getCreationTime()
+  {
+    return create_time;
+
+  } // end getCreationTime
+
+  public String getID()
+  {
+    return id;
+
+  } // end getID
+
+  public long getLastAccessedTime()
+  {
+    return access_time;
+
+  } // end getLastAccessedTime
+
+  public synchronized void setMaxInactiveInterval(int interval)
+  {
+    max_inactive = interval;
+    touch();
+
+  } // end setMaxInactiveInterval
+
+  public int getMaxInactiveInterval()
+  {
+    return max_inactive;
+
+  } // end getMaxInactiveInterval
+
+  public Object getAttribute(String name)
+  {
+    return attrs.get(name);
+
+  } // end getAttribute
+
+  public Enumeration getAttributeNames()
+  {
+    return Collections.enumeration(attrs.keySet());
+
+  } // end getAttributeNames
+
+  public synchronized void setAttribute(String name, Object o)
+  {
+    attrs.put(name,o);
+    touch();
+
+  } // end setAttribute
+
+  public synchronized void removeAttribute(String name)
+  {
+    attrs.remove(name);
+    touch();
+
+  } // end removeAttribute
+
+  public synchronized void invalidate()
+  {
+    broker.detachSession(id);
+    broker = null;
+    attrs.clear();
+
+  } // end invalidate
+
+  public UserContext getUser()
+  {
+    return user;
+
+  } // end getUser
+
+  public synchronized void setUser(UserContext user)
+  {
+    this.user = user;
+    touch();
+
+  } // end setUser
+
+  public void preprocess(RequestInput ri)
+  { // do nothing
+  } // end preprocess
+
+  /*--------------------------------------------------------------------------------
+   * External operations
+   *--------------------------------------------------------------------------------
+   */
+
+  final synchronized boolean canUnloadNow()
+  {
+    return ((System.currentTimeMillis() - access_time) > ((long)1000 * max_inactive));
+
+  } // end canUnloadNow
+
+  final synchronized void touch()
+  {
+    access_time = System.currentTimeMillis();
+
+  } // end touch
+
+} // end class RpcVeniceUISession

src/com/silverwrist/venice/ui/rpc/XmlRpcCreateSession.java

@@ -0,0 +1,50 @@
+/*
+ * The contents of this file are subject to the Mozilla Public License Version 1.1
+ * (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
+ * 
+ * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
+ * WARRANTY OF ANY KIND, either express or implied. See the License for the specific
+ * language governing rights and limitations under the License.
+ * 
+ * The Original Code is the Venice Web Communities System.
+ * 
+ * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
+ * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
+ * Copyright (C) 2002 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * 
+ * Contributor(s): 
+ */
+package com.silverwrist.venice.ui.rpc;
+
+import java.util.*;
+import org.apache.log4j.*;
+import com.silverwrist.venice.ui.*;
+
+public class XmlRpcCreateSession implements XmlRpcDispatch
+{
+  /*--------------------------------------------------------------------------------
+   * Static data members
+   *--------------------------------------------------------------------------------
+   */
+
+  private static Category logger = Category.getInstance(XmlRpcCreateSession.class);
+
+  /*--------------------------------------------------------------------------------
+   * Implementations from interface XmlRpcDispatch
+   *--------------------------------------------------------------------------------
+   */
+
+  public Object dispatch(RequestInput req, XmlRpcRequest xreq, Map environment) throws Exception, XmlRpcFault
+  {
+    if (logger.isDebugEnabled())
+      logger.debug("Dispatching a Create Session call");
+    VeniceUISession session = RpcSessionBroker.get(req).createSession(req.getSourceAddress());
+    if (logger.isDebugEnabled())
+      logger.debug("Created new session with ID " + session.getID());
+    return session.getID();
+
+  } // end dispatch
+
+} // end class XmlRpcSession
+

src/com/silverwrist/venice/ui/rpc/XmlRpcFault.java

@@ -19,6 +19,7 @@ package com.silverwrist.venice.ui.rpc;
 
 import java.io.IOException;
 import com.silverwrist.util.StringUtil;
+import com.silverwrist.venice.except.SupplyFaultCode;
 import com.silverwrist.venice.ui.*;
 import com.silverwrist.venice.ui.helpers.ThrowableContent;
 
@@ -67,6 +68,12 @@ public class XmlRpcFault extends ThrowableContent implements ContentExecute
   public XmlRpcFault(Throwable t)
   {
     super(t);
+    if (t instanceof SupplyFaultCode)
+    { // retrieve the fault code
+      SupplyFaultCode sfc = (SupplyFaultCode)t;
+      fault_code = sfc.getFaultCode();
+
+    } // end if
 
   } // end constructor
 
@@ -80,6 +87,12 @@ public class XmlRpcFault extends ThrowableContent implements ContentExecute
   public XmlRpcFault(String msg, Throwable t)
   {
     super(msg,t);
+    if (t instanceof SupplyFaultCode)
+    { // retrieve the fault code
+      SupplyFaultCode sfc = (SupplyFaultCode)t;
+      fault_code = sfc.getFaultCode();
+
+    } // end if
 
   } // end constructor
 

src/com/silverwrist/venice/ui/rpc/XmlRpcMethod.java

@@ -49,6 +49,7 @@ public class XmlRpcMethod
   private Class obj_class = null;     // "class" handler for object
   private String script_name = null;  // script name to use as a handler
   private Map raw_env;                // "raw" environment
+  private int session_param = -1;     // session parameter
 
   /*--------------------------------------------------------------------------------
    * Constructor
@@ -119,7 +120,15 @@ public class XmlRpcMethod
     else  // no handler - this is an error
       throw new ConfigException("method \"" + method_name + "\" does not have a valid handler",cfg);
 
-    NodeList nl = sub.getChildNodes();
+    if ((sub = cfg_h.getSubElement("session"))!=null)
+    { // find the session parameter index
+      session_param = loader.configGetAttributeInt(sub,"param");
+      if (session_param<0)
+	throw new ConfigException("invalid session parameter index",sub);
+
+    } // end if
+
+    NodeList nl = cfg.getChildNodes();
     HashMap tmp_env = new HashMap();
     for (int i=0; i<nl.getLength(); i++)
     { // look for specific nodes
@@ -141,6 +150,38 @@ public class XmlRpcMethod
 
   } // end constructor
 
+  /*--------------------------------------------------------------------------------
+   * Internal operations
+   *--------------------------------------------------------------------------------
+   */
+
+  private final void bindSession(RequestInput req, XmlRpcRequest xreq) throws XmlRpcFault
+  {
+    if (logger.isDebugEnabled())
+      logger.debug("trying to bind parameter at index " + session_param + " to session");
+    if (session_param>=xreq.getParamCount())
+    { // too few parameters - bail out!
+      logger.error("session parameter is at index " + session_param + " but only " + xreq.getParamCount()
+		   + " parameter(s) present");
+      throw new XmlRpcFault(XmlRpcFault.SERVER_ERROR,"invalid parameter index for session binding");
+
+    } // end if
+
+    String session_id = xreq.getParamString(session_param).trim();
+    if (logger.isDebugEnabled())
+      logger.debug("Passed session ID = " + session_id);
+    VeniceUISession vuis = RpcSessionBroker.get(req).getSession(session_id);
+    if (vuis==null)
+    { // the session cannot be acquired
+      logger.debug("Cannot get session for session ID " + session_id);
+      throw new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"session not found");
+
+    } // end if
+
+    req.pushSession(vuis);  // push the session into the request
+
+  } // end bindSession
+
   /*--------------------------------------------------------------------------------
    * External operations
    *--------------------------------------------------------------------------------
@@ -181,7 +222,20 @@ public class XmlRpcMethod
 
       } // end if
 
-      return disp.dispatch(req,xreq,env);  // dispatch the call
+      if (session_param>=0)
+	bindSession(req,xreq);
+
+      try
+      { // dispatch the call
+	return disp.dispatch(req,xreq,env);
+
+      } // end try
+      finally
+      { // pop the session we pushed
+	if (session_param>=0)
+	  req.popSession();
+
+      } // end finally
 
     } // end if
 
@@ -193,18 +247,35 @@ public class XmlRpcMethod
 	logger.debug("EXECUTING " + full_name);
       try
       { // execute the script!
+	if (session_param>=0)
+	  bindSession(req,xreq);
+
 	ScriptManager smgr = req.getScriptManager();
 	smgr.pushContext();
 	smgr.register("xmlrpc",xreq);
 	smgr.register("environment",env);
+	try
+	{ // execute the script
 	  ScriptReturn sro = new ScriptReturn();
 	  smgr.exec(new File(full_name),logger_name,sro);
-	smgr.popContext();
 	  return sro.get();
 
+	} // end try
+	finally
+	{ // make sure and pop the context before we return
+	  smgr.popContext();
+	  if (session_param>=0)
+	    req.popSession();
+
+	} // end finally
+
       } // end try
       catch (ScriptingException se)
       { // script error!  we are not amused...
+	Throwable t = se.getException();
+	if (t instanceof SupplyFaultCode)
+	  return new XmlRpcFault(t);
+	else
 	  return new XmlRpcFault(XmlRpcFault.APPLICATION_ERROR,"scripting error: " + se.toString());
 
       } // end catch

src/com/silverwrist/venice/ui/rpc/XmlRpcMulticall.java

@@ -99,7 +99,7 @@ public class XmlRpcMulticall implements XmlRpcDispatch
     while (it.hasNext())
     { // parse out a request and dispatch it
       try
-      { // parse the request
+      { // parse the request, execute it, and add its result to the return array
 	XmlRpcRequest sub_xreq = parseRequest(req,it.next());
 	Object sub_rc = XmlRpcServlet.dispatchMethodCall(req,sub_xreq);
 	if (sub_rc instanceof XmlRpcFault)

src/com/silverwrist/venice/ui/rpc/XmlRpcRequest.java

@@ -24,6 +24,7 @@ import javax.mail.internet.*;
 import org.apache.log4j.*;
 import org.w3c.dom.*;
 import com.silverwrist.util.*;
+import com.silverwrist.venice.core.*;
 import com.silverwrist.venice.except.*;
 import com.silverwrist.venice.ui.*;
 import com.silverwrist.venice.util.XMLLoader;
@@ -59,8 +60,7 @@ public class XmlRpcRequest
       throw new XmlRpcFault(XmlRpcFault.INVALID_REQUEST,"no XML call structure found");
 
     try
-    {
+    { // load the initial structure and method name
-      // load the initial structure and method name
       XMLLoader loader = XMLLoader.get();
       Element root = loader.postGetRootElement(req_doc,"methodCall");
       DOMElementHelper root_h = new DOMElementHelper(root);
@@ -475,4 +475,49 @@ public class XmlRpcRequest
 
   } // end getParamString
 
+  public final CommunityContext getParamCommunity(int ndx) throws XmlRpcFault, DataException
+  {
+    Object foo = method_params.get(ndx);
+    if ((foo instanceof byte[]) || (foo instanceof List) || (foo instanceof Map) || (foo instanceof Boolean))
+      throw new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter type mismatch");
+    if (foo instanceof Integer)
+      return req.getUser().getCommunityContext(((Integer)foo).intValue());
+    else
+      return req.getUser().getCommunityContext(foo.toString().trim());
+
+  } // end getParamCommunity
+
+  public final ConferenceContext getParamConference(int ndx, CommunityContext comm)
+      throws XmlRpcFault, DataException, AccessError
+  {
+    Object foo = method_params.get(ndx);
+    if ((foo instanceof byte[]) || (foo instanceof List) || (foo instanceof Map) || (foo instanceof Boolean))
+      throw new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter type mismatch");
+    if (foo instanceof Integer)
+      return comm.getConferenceContext(((Integer)foo).intValue());
+    else
+      return comm.getConferenceContext(foo.toString().trim());
+
+  } // end getParamConference
+
+  public final TopicContext getParamTopic(int ndx, ConferenceContext conf)
+      throws XmlRpcFault, DataException, AccessError
+  {
+    Object foo = method_params.get(ndx);
+    if (!(foo instanceof Integer))
+      throw new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter type mismatch");
+    return conf.getTopic(((Integer)foo).shortValue());
+
+  } // end getParamTopic
+
+  public final TopicMessageContext getParamPost(int ndx, TopicContext topic)
+      throws XmlRpcFault, DataException, AccessError
+  {
+    Object foo = method_params.get(ndx);
+    if (!(foo instanceof Integer))
+      throw new XmlRpcFault(XmlRpcFault.INVALID_PARAMS,"parameter type mismatch");
+    return topic.getMessage(((Integer)foo).intValue());
+
+  } // end getParamPost
+
 } // end class XmlRpcRequest

src/com/silverwrist/venice/ui/rpc/XmlRpcServlet.java

@@ -21,6 +21,7 @@ import java.io.*;
 import java.util.*;
 import javax.servlet.*;
 import javax.servlet.http.*;
+import org.apache.log4j.*;
 import org.apache.regexp.*;
 import com.silverwrist.util.*;
 import com.silverwrist.venice.core.*;
@@ -76,6 +77,8 @@ public class XmlRpcServlet extends BaseServlet
    *--------------------------------------------------------------------------------
    */
 
+  private static Category logger = Category.getInstance(XmlRpcServlet.class);
+
   private static final String METHOD_LIST_ATTR = "ui.xmlrpc.MethodList";
 
   public static final String OBJECT_CLASS_CACHE_ATTR = "ui.xmlrpc.class.ObjectCache";
@@ -91,6 +94,7 @@ public class XmlRpcServlet extends BaseServlet
     List methods = root.getXmlRpcMethods();
     RequestImpl.setAppAttribute(ctxt,METHOD_LIST_ATTR,methods);
     RequestImpl.setAppAttribute(ctxt,OBJECT_CLASS_CACHE_ATTR,Collections.synchronizedMap(new HashMap()));
+    RpcSessionBroker.init(ctxt,engine,root);
 
   } // end init
 
@@ -135,7 +139,10 @@ public class XmlRpcServlet extends BaseServlet
 
   static Object dispatchMethodCall(RequestInput req, XmlRpcRequest xreq)
   {
-    // Prepare the parameters map
+    if (logger.isDebugEnabled())
+      logger.debug("XML-RPC Method Call: " + xreq.getMethod());
+
+    // Prepare the parameters map.
     int i;
     HashMap param_repl_map = new HashMap();
     for (i=0; i<xreq.getParamCount(); i++)
@@ -166,19 +173,26 @@ public class XmlRpcServlet extends BaseServlet
 
       } // end while
 
-      if (!found)  // method not found
+      if (!found)
+      { // method not found
+	logger.error("Method not found: " + the_name);
 	return new XmlRpcFault(XmlRpcFault.METHOD_NOT_FOUND,"Method not found: " + the_name);
 
+      } // end if
+
       // prepare the substitution map
       sub_map = (HashMap)(param_repl_map.clone());
       int ct = matcher.getParenCount();
       for (i=0; i<=ct; i++)
 	sub_map.put("match." + i,matcher.getParen(i));
 
+      // test for method remapping
       String remap = meth.getRemap();
       if (remap!=null)
       { // substitute in variables and rescan
 	the_name = StringUtil.replaceAllVariables(remap,sub_map);
+	if (logger.isDebugEnabled())
+	  logger.debug("-- call remapped to method: " + the_name);
 	rescan = true;
 
       } // end if

src/com/silverwrist/venice/ui/script/ScriptLibrary.java

@@ -11,7 +11,7 @@
  * 
  * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
  * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
- * Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * Copyright (C) 2001-02 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
  * 
  * Contributor(s): 
  */
@@ -31,6 +31,20 @@ public class ScriptLibrary
    *--------------------------------------------------------------------------------
    */
 
+  public final Boolean booleanObject(boolean b)
+  {
+    return (b ? Boolean.TRUE : Boolean.FALSE);
+
+  } // end booleanObject
+
+  public final byte[] castByteArray(Object o)
+  {
+    if (o instanceof byte[])
+      return (byte[])o;
+    throw new ClassCastException("ScriptLibrary.castByteArray: invalid cast");
+
+  } // end castByteArray
+
   public final ConferenceContext castConferenceContext(Object o)
   {
     if (o instanceof ConferenceContext)

src/com/silverwrist/venice/ui/script/ScriptManager.java

@@ -11,7 +11,7 @@
  * 
  * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
  * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
- * Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
+ * Copyright (C) 2001-02 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
  * 
  * Contributor(s): 
  */
@@ -264,8 +264,12 @@ public class ScriptManager
     { // throw a ScriptingException
       logger.error("Execution exception while running script",t);
       if (t!=null)
+      { // throw THIS exception
+	logger.error("Exception type: " + t.getClass().getName());
 	throw new ScriptingException(source,lang,e.getMessage(),t);
-      else
+
+      } // end if
+      else  // throw the regular old name
 	throw new ScriptingException(source,lang,e.getMessage(),e);
       
     } // end if
@@ -273,15 +277,20 @@ public class ScriptManager
     { // usually indicates a compiler error in the scripting engine
       logger.error("Script compilation error",e);
       if (t!=null)
-	logger.error("Root cause:",t);
+      { // throw THIS exception
-      throw new ScriptingException(source,lang,e.getMessage());
+	logger.error("Exception type: " + t.getClass().getName());
+	throw new ScriptingException(source,lang,e.getMessage(),t);
+
+      } // end if
+      else  // throw the regular old name
+	throw new ScriptingException(source,lang,e.getMessage(),e);
 
     } // end else if
     else
     { // unknown exception type here!
       logger.error("Unknown BSFException in script execution (reason " + e.getReason() + ")",e);
       if (t!=null)
-	logger.error("Root cause:",t);
+	logger.error("Root cause (type " + t.getClass().getName() + "):",t);
       throw new ScriptingException("unexpected exception while executing " + source + " [" + lang + "]",e);
 
     } // end else

src/com/silverwrist/venice/ui/servlet/RequestImpl.java

@@ -583,6 +583,7 @@ public class RequestImpl implements RequestInput
   private CommunityContext community = null;             // the current community
   private LinkedList auto_cleanup = null;                // auto-cleanup callbacks
   private Document request_doc = null;                   // request parsed as an XML document
+  private LinkedList session_stack = null;               // session stack
 
   /*--------------------------------------------------------------------------------
    * Constructor
@@ -1555,6 +1556,22 @@ public class RequestImpl implements RequestInput
 
   } // end registerCleanup
 
+  public void pushSession(VeniceUISession sess)
+  {
+    if (session_stack==null)
+      session_stack = new LinkedList();
+    session_stack.addFirst(session);
+    session = sess;
+
+  } // end pushSession
+
+  public void popSession()
+  {
+    if ((session_stack!=null) && (session_stack.size()>0))
+      session = (VeniceUISession)(session_stack.removeFirst());
+
+  } // end popSession
+
   /*--------------------------------------------------------------------------------
    * External static operations
    *--------------------------------------------------------------------------------