DPML Notify

[mcconnell AT dpml.net]

Author: mcconnell AT dpml.net
Date: Thu May 19 00:11:11 2005
New Revision: 2604

Added:
   
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/
   
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagedComponent.java
   
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagingContainer.java
Modified:
   development/main/test/components/acme-config/build.xml
Log:
add state managed components

Modified: development/main/test/components/acme-config/build.xml
==============================================================================
--- development/main/test/components/acme-config/build.xml      (original)
+++ development/main/test/components/acme-config/build.xml      Thu May 19 
00:11:11 2005
@@ -7,7 +7,12 @@
   <transit:import uri="artifact:template:dpml/magic/standard"/>
 
   <target name="build" depends="standard.build">
-
+    <types xmlns="plugin:dpml/composition/dpml-composition-builder">
+      <type class="net.dpml.test.acme.config.ConfigurableComponent" 
threadsafe="true"/>
+      <type class="net.dpml.test.acme.config.ConfigurableContainer" 
threadsafe="true"/>
+      <type class="net.dpml.test.acme.state.ManagedComponent" 
threadsafe="true"/>
+      <type class="net.dpml.test.acme.state.ManagingContainer" 
threadsafe="true"/>
+    </types>
   </target>
 
 </project>

Added: 
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagedComponent.java
==============================================================================
--- (empty file)
+++ 
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagedComponent.java
        Thu May 19 00:11:11 2005
@@ -0,0 +1,224 @@
+/*
+ * Copyright 2005 Stephen J. McConnell.
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.test.acme.state;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.logging.Logger;
+
+import net.dpml.parts.state.State;
+import net.dpml.parts.state.StateEvent;
+import net.dpml.parts.state.StateListener;
+
+/**
+ * Experimental component dealing with state management.
+ * 
+ * @author <a href="mailto:info AT dpml.net";>The Digital Product Meta 
Library</a>
+ */
+public class ManagedComponent implements StateListener
+{
+    // ------------------------------------------------------------------
+    // state
+    // ------------------------------------------------------------------
+
+    private final Logger m_logger;
+
+    // ------------------------------------------------------------------
+    // constructor
+    // ------------------------------------------------------------------
+
+    /**
+     * Creation of a component that describes an activity model.
+     * 
+     * @param logger the logging channel assigned by the container
+     */
+    public ManagedComponent( final Logger logger, Context context )
+    {
+        m_logger = logger;
+        context.addStateListener( this );
+    }
+
+    /**
+     * Notify the listener of a state change.  The supplied event
+     * contains the originating state and the state that is about to 
+     * be committed.
+     *
+     * @param event the state change event
+     */
+    public void stateChanged( final StateEvent event )
+    {
+        State source = event.getFromState();
+        State destination = event.getToState();
+        final String message = 
+          "transitioning from '" 
+          + source.getName() 
+          + "' to '"
+          + destination.getName()
+          + "'";
+        m_logger.info( message );
+    }
+
+    // ------------------------------------------------------------------
+    // concerns
+    // ------------------------------------------------------------------
+
+    public interface Context
+    {
+         void addStateListener( StateListener listener );
+    }
+
+    // ------------------------------------------------------------------
+    // implementation
+    // ------------------------------------------------------------------
+
+    private Logger getLogger()
+    {
+        return m_logger;
+    }
+
+    //
+    // The following methods are invoked by the state manager based on 
+    // uris assigned to transitions.  The state manager locates the method
+    // from the uri and invokes the operation after constructing arguments
+    // from the possible set of Logger, Object (component impl), State 
(initial),
+    // and State (target).  If the method requires the target state it must 
+    // delcare both current and target state in the method parameters.
+    //
+
+    public void terminate( State state )
+    {
+        String name = state.getName();
+        getLogger().info( "handling termination within " + name );
+    }
+
+    public void start( State starting )
+    {
+        String from = starting.getName();
+        getLogger().info( "starting from within " + from );
+    }
+
+    public void stop()
+    {
+        getLogger().info( "stopping the component" );
+    }
+
+    //
+    // The following method is an example of a method invoked 
+    // via an operation declaration. Operations do not trigger state 
+    // change - instead they are gaurded methods that become visible
+    // to a controlling application when the state to which the operation
+    // is assigned becomes visible in the active state chain.
+    //
+
+    public void audit( State state )
+    {
+        StringBuffer buffer = new StringBuffer( "Audit Report" );
+        buffer.append( "\n-------------------------------------------------" 
);
+        buffer.append( "\nState Model:" );
+        buffer.append( "\nCurrent State: " + state.getName() );
+        buffer.append( "\n-------------------------------------------------" 
);
+        buffer.append( STATE_GRAPH.list() );
+        buffer.append( "\n-------------------------------------------------" 
);
+        buffer.append( "\nClass Loader Stack" );
+        buffer.append( "\n-------------------------------------------------" 
);
+        buffer.append( "\n" + getClass().getClassLoader().toString() );
+        buffer.append( "\n-------------------------------------------------" 
);
+        getLogger().info( buffer.toString() );
+    }
+
+    // ------------------------------------------------------------------
+    // static utilities
+    // ------------------------------------------------------------------
+
+    public static final State STATE_GRAPH = new State();
+
+    static
+    {
+        //
+        // construct a state graph
+        //
+
+        State root = STATE_GRAPH;
+        State initialized = root.addState( "initialized" );
+        State available = root.addState( "available" );
+        State started = available.addState( "started" );
+        State stopped = available.addState( "stopped" );
+        State terminated = root.addTerminalState( "terminated" );
+
+        //
+        // create the handler declarations 
+        //
+
+        try
+        {
+            //
+            // add system transitions dealing with initilization and 
+            // termination - each transition is added to a particular 
+            // state and is qualified with the uri of the handler to 
+            // use, and the transitions target state
+            //
+
+            root.setInitialization( initialized );
+            root.setTerminator( new URI( "method:null" ), terminated );
+            started.setTerminator( new URI( "method:stop" ), stopped );
+
+            //
+            // add user (application) transitions
+            //
+
+            initialized.addTransition( "start", new URI( "method:start" ), 
started );
+            started.addTransition( "stop", new URI( "method:stop" ), stopped 
);
+            stopped.addTransition( "start", new URI( "method:start" ), 
started );
+
+            //
+            // add an operations that is only accessible in the active state 
chain
+            // when the component is in the started state
+            //
+
+            started.addOperation( "audit", new URI( "method:audit" ) ); 
+
+        }
+        catch( URISyntaxException e )
+        {
+            // will not happen
+        }
+    }
+
+    //
+    // The following class is an example of a transition handler.  Instances
+    // of this class may be registered with the state manager and referenced 
in 
+    // transitiond via the urn "handler:[key]".
+    //
+
+    private static final Handler GENERIC_HANDLER = new Handler();
+
+    public static class Handler
+    {
+        public void handle( ManagedComponent instance, State state, State 
target, Logger logger )
+        {
+            final String message = 
+              "handling transition from [" 
+              + state.getName()
+              + "] to ["
+              + target.getName()
+              + "]";
+            logger.info( message );
+        }
+    }
+}

Added: 
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagingContainer.java
==============================================================================
--- (empty file)
+++ 
development/main/test/components/acme-config/src/main/net/dpml/test/acme/state/ManagingContainer.java
       Thu May 19 00:11:11 2005
@@ -0,0 +1,100 @@
+/*
+ * Copyright 2005 Stephen J. McConnell.
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.test.acme.state;
+
+import java.net.URI;
+import java.util.logging.Logger;
+
+import net.dpml.parts.control.Manager;
+import net.dpml.parts.model.Component;
+import net.dpml.parts.state.State;
+
+import net.dpml.activity.Startable;
+
+/**
+ * Demonstration of a component that manages the state of a contained part.
+ * 
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ */
+public class ManagingContainer implements Startable
+{
+    //------------------------------------------------------------------
+    // state
+    //------------------------------------------------------------------
+
+    private final Logger m_logger;
+    private final Parts m_parts;
+
+    //------------------------------------------------------------------
+    // constructor
+    //------------------------------------------------------------------
+
+   /**
+    * Creation of a composite component. This implementation demonstrates
+    * access to parts within itself and invocation of service and non-service
+    * operations on its parts.
+    *
+    * @param logger the logging channel asign by the container
+    */
+    public ManagingContainer( final Logger logger, Parts parts )
+    {
+         m_logger = logger;
+         m_parts = parts;
+    }
+
+    //------------------------------------------------------------------
+    // implementation
+    //------------------------------------------------------------------
+
+    public void start() throws Exception
+    {
+         Parts parts = getParts();
+         Component component = parts.getTestComponent();
+         component.initialize();
+         component.resolve();
+         component.apply( "start" );
+         component.execute( "audit" );
+    }
+
+    public void stop() throws Exception
+    {
+         Parts parts = getParts();
+         Component component = parts.getTestComponent();
+         component.terminate();
+    }
+
+    private Logger getLogger()
+    {
+        return m_logger;
+    }
+
+    private Parts getParts()
+    {  
+        return m_parts;
+    }
+
+    //------------------------------------------------------------------
+    // concerns
+    //------------------------------------------------------------------
+
+    public interface Parts
+    {
+        Component getTestComponent();
+    }
+}