Creating Agents without XML

[Todd Wright]

Christian Bernardt wrote:
> Hi there,
> 
> I am trying to figure out, how to create an agent society without 
> defining the agents in a xml file. This way of managing societies is 
> described on page 18 of the CAD. (section 3.2.1 Initialization). I have 
> created a number of empty Nodes representing the spaces, the agents 
> shall be created in. I would like to create agents in these societies, 
> while cougaar is running.
> 1.)How can I add/remove agents to/from the nodes during runtime?

You can use the blackboard-based "AddTicket" approach, as discussed in:
   http://www.cougaar.org/pipermail/cougaar-developers/2007-May/002349.html
This approach works from any agent or even a remote node.

Or, if you only want to add an agent to the local node, you can call the 
"addAgent" method.  This requires a plugin in the node agent.  The above 
"AddTicket" code uses the "addAgent" method.  Here's an example:
------------------------------------------------------------------------------
package whatever;

import org.cougaar.core.agent.AgentContainer;
import org.cougaar.core.component.ComponentSupport;
import org.cougaar.core.mts.MessageAddress;
import org.cougaar.core.node.NodeControlService;
import org.cougaar.core.service.LoggingService;
import org.cougaar.core.service.ThreadService;
import org.cougaar.core.thread.Schedulable;

public class AddAgent extends ComponentSupport {
   private LoggingService log;
   private ThreadService ts;
   private AgentContainer ac;

   public void setLoggingService(LoggingService log) { this.log = log; }
   public void setThreadService(ThreadService ts) { this.ts = ts; }
   public void setNodeControlService(NodeControlService ncs) {
     ac = (ncs == null ? null : ncs.getRootContainer());
   }

   public void start() {
     super.start();

     // add our agent after 5 seconds.  For threading info see:
     // 
http://www.cougaar.org/pipermail/cougaar-developers/2004-October/001491.html
     Runnable r = new Runnable() {
       public void run() {
         log.shout("Adding agent Foo");
         ac.addAgent(MessageAddress.getMessageAddress("Foo"));
       }
     };
     Schedulable s = ts.getThread(this, r);
     log.shout("Waiting 5 seconds");
     s.schedule(5*1000);
   }
}
------------------------------------------------------------------------------

"MyNode.xml":
------------------------------------------------------------------------------
<?xml version='1.0'?>
<node name="Node1">
   <component class="whatever.AddAgent"/>  <!-- must be in the node agent -->
</node>
------------------------------------------------------------------------------

"Foo.xml":
------------------------------------------------------------------------------
<?xml version='1.0'?>
<agent name="Foo">
   <!-- anything, e.g. the hello-world plugin in the demo-hello.zip -->
   <component class="org.cougaar.demo.hello.HelloPlugin"/>
</agent>
------------------------------------------------------------------------------

Logging output:
------------------------------------------------------------------------------
2008-03-26 17:17:01,410 SHOUT [XMLComponentInitializerServiceProvider] - 
Initializing node "Node1" from XML file "MyNode.xml"
2008-03-26 17:17:11,427 WARN  [AgentLoader] - Node1: Node Node1 contains zero 
agents
2008-03-26 17:17:11,444 SHOUT [AddAgent] - Node1: Waiting 5 seconds
2008-03-26 05:17:16,441 SHOUT [DOTS] - .
2008-03-26 17:17:16,449 SHOUT [AddAgent] - Node1: Adding agent Foo
2008-03-26 17:17:16,694 SHOUT [HelloPlugin] - Foo: Hello, world!
------------------------------------------------------------------------------

Note that you must have a "Foo.xml" file in the Cougaar config path (e.g. the 
current directory).  There's an enhancement request to allow an in-memory 
specification of what plugins to put in the agent, but that hasn't been 
implemented yet.

> 2.)Can I create such agents from outside of a node? If, how?

You'll need some way to tell the node to create the agent, e.g. a servlet.

 From there you can use either of the above techniques:
   1) Use the blackboard-based "AddTicket"
or
   2) Use the service-based "addAgent" method

> 3.)How can I address the nodes that I have initialized in the xml file?

You name the agents when you create them, e.g. the above "Foo" example.  You 
can send blackboard relays to them.

Todd

> 
> I am totally new to cougaar, can anybody give me a jump start on how to 
> achieve these things?
> 
> Thanks in advance.  Chris
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Cougaar-developers mailing list
> Cougaar-developers at cougaar.org
> http://cougaar.org/mailman/listinfo/cougaar-developers