2009/05/20 - Apache Shale has been retired.

 /*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to you 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 org.apache.shale.dialog.basic.config;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.URL;

 import java.util.Map;

 import org.apache.commons.digester.Digester;

 import org.apache.commons.digester.Rule;

 import org.apache.shale.dialog.basic.model.Dialog;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 /**

  * <p>Configuration utility for parsing configuration resources for

  * defining dialogs.  This class has no dependencies on web tier APIs,

  * only on the parsing technology (Commons Digester) being used.</p>

  *

  * <p>To use this utility, instantiate a new instance and set the

  * <code>dialogs</code>, <code>resource</code>, and <code>validating</code>

  * properties.  Then, call the <code>parse()</code> method.  You can parse

  * more than one resource by resetting the <code>resource</code>

  * property and calling <code>parse()</code> again.</p>

  *

  * @since 1.0.4

  */

 public final class ConfigurationParser {

     // ------------------------------------------------------ Instance Variables

     /**

      * <p>Registration information for the DTD we will use to validate.</p>

      */

     private static final String[] REGISTRATIONS =

     { "-//Apache Software Foundation//DTD Shale Dialog Configuration 1.0//EN",

       "/org/apache/shale/dialog/dialog-config_1_0.dtd",

       "-//Apache Software Foundation//DTD Shale Dialog Configuration 1.1//EN",

       "/org/apache/shale/dialog/dialog-config_1_1.dtd" };

     // -------------------------------------------------------------- Properties

     /**

      * <p><code>Map</code> of <code>Dialog</code> instances resulting

      * from parsing, keyed by dialog name.</p>

      */

     private Map dialogs = null;

     /**

      * <p>Return the <code>Map</code> of <code>Dialog</code> instances

      * into which parsed information will be stored, keyed by dialog

      * name.</p>

      *

      * @return The map of available {@link Dialog}s, keyed by name

      */

     public Map getDialogs() {

         return this.dialogs;

     }

     /**

      * <p>Set the <code>Map</code> of <code>Dialog</code> instances

      * into which parsed information will be stored, keyed by dialog

      * name.</p>

      *

      * @param dialogs The new map

      */

     public void setDialogs(Map dialogs) {

         this.dialogs = dialogs;

     }

     /**

      * <p>The URL of the configuration resource to be parsed.</p>

      */

     private URL resource = null;

     /**

      * <p>Return the URL of the configuration resource to be parsed.</p>

      *

      * @return The URL of the dialogs configuration resource

      */

     public URL getResource() {

         return this.resource;

     }

     /**

      * <p>Set the URL of the configuration resource to be parsed.</p>

      *

      * @param resource The new resource URL

      */

     public void setResource(URL resource) {

         this.resource = resource;

     }

     /**

      * <p>Flag indicating whether we should do a validating parse or not.</p>

      */

     private boolean validating = true;

     /**

      * <p>Return a flag indicating whether we will be doing a validating parse

      * or not.  Default value is <code>true</code>.</p>

      *

      * @return Whether the parse is a validating one

      */

     public boolean isValidating() {

         return this.validating;

     }

     /**

      * <p>Set a flag indicating whether we will be doing a validating parse

      * or not.</p>

      *

      * @param validating New flag value

      */

     public void setValidating(boolean validating) {

         this.validating = validating;

     }

     // ---------------------------------------------------------- Public Methods

     /**

      * <p>Parse the configuration resource identified by the <code>resource</code>

      * property, storing resulting information in the <code>Map</code> specified

      * by the <code>dialogs</code> property.</p>

      *

      * @exception IOException if an input/output error occurs

      * @exception SAXException if an XML parsing error occurs

      */

     public void parse() throws IOException, SAXException {

         Digester digester = digester();

         digester.clear();

         digester.push(getDialogs());

         InputSource source = new InputSource(getResource().toExternalForm());

         InputStream stream = null;

         try {

             stream = getResource().openStream();

             source.setByteStream(stream);

             digester.parse(source);

         } catch (IOException e) {

             throw e;

         } catch (SAXException e) {

             throw e;

         } finally {

             if (stream != null) {

                 try {

                     stream.close();

                 } catch (IOException e) {

                     ; // Fall through

                 }

             }

         }

     }

     // --------------------------------------------------------- Private Methods

     /**

      * <p>Return a fully configured <code>Digester</code> instance.</p>

      *

      * @return The fully configured {@link Digester} instance for parsing

      *         the dialog configuration resource

      */

     private Digester digester() {

         Digester digester = new Digester();

         // Configure global characteristics

         digester.setNamespaceAware(false);

         digester.setUseContextClassLoader(true);

         digester.setValidating(isValidating());

         // Register local copy of our DTDs

         for (int i = 0; i < REGISTRATIONS.length; i += 2) {

             URL url = this.getClass().getResource(REGISTRATIONS[i + 1]);

             digester.register(REGISTRATIONS[i], url.toString());

         }

         // Configure processing rules

         // dialogs/dialog

         digester.addObjectCreate("dialogs/dialog", "className", DialogImpl.class);

         digester.addSetProperties("dialogs/dialog");

         digester.addSetProperty("dialogs/dialog/property", "name", "value");

         digester.addRule("dialogs/dialog", new AddDialogRule());

         // dialogs/dialog/action

         digester.addObjectCreate("dialogs/dialog/action", "className",

                                  ActionStateImpl.class);

         digester.addSetProperties("dialogs/dialog/action");

         digester.addSetProperty("dialogs/dialog/action/property", "name", "value");

         digester.addSetNext("dialogs/dialog/action",

                             "addState", "org.apache.shale.dialog.basic.model.State");

         // dialogs/dialog/action/transition

         digester.addObjectCreate("dialogs/dialog/action/transition", "className",

                                  TransitionImpl.class);

         digester.addSetProperties("dialogs/dialog/action/transition");

         digester.addSetProperty("dialogs/dialog/action/transition/property", "name", "value");

         digester.addSetNext("dialogs/dialog/action/transition",

                             "addTransition", "org.apache.shale.dialog.basic.model.Transition");

         // dialogs/dialog/end

         digester.addObjectCreate("dialogs/dialog/end", "className",

                                  EndStateImpl.class);

         digester.addSetProperties("dialogs/dialog/end");

         digester.addSetProperty("dialogs/dialog/end/property", "name", "value");

         digester.addSetNext("dialogs/dialog/end",

                             "addState", "org.apache.shale.dialog.basic.model.State");

         // dialogs/dialog/end/transition

         digester.addObjectCreate("dialogs/dialog/end/transition", "className",

                                  TransitionImpl.class);

         digester.addSetProperties("dialogs/dialog/end/transition");

         digester.addSetProperty("dialogs/dialog/end/transition/property", "name", "value");

         digester.addSetNext("dialogs/dialog/end/transition",

                             "addTransition", "org.apache.shale.dialog.basic.model.Transition");

         // dialogs/dialog/subdialog

         digester.addObjectCreate("dialogs/dialog/subdialog", "className",

                                  SubdialogStateImpl.class);

         digester.addSetProperties("dialogs/dialog/subdialog");

         digester.addSetProperty("dialogs/dialog/subdialog/property", "name", "value");

         digester.addSetNext("dialogs/dialog/subdialog",

                             "addState", "org.apache.shale.dialog.basic.model.State");

         // dialogs/dialog/subdialog/transition

         digester.addObjectCreate("dialogs/dialog/subdialog/transition", "className",

                                  TransitionImpl.class);

         digester.addSetProperties("dialogs/dialog/subdialog/transition");

         digester.addSetProperty("dialogs/dialog/subdialog/transition/property", "name", "value");

         digester.addSetNext("dialogs/dialog/subdialog/transition",

                             "addTransition", "org.apache.shale.dialog.basic.model.Transition");

         // dialogs/dialog/transition

         digester.addObjectCreate("dialogs/dialog/transition", "className",

                                  TransitionImpl.class);

         digester.addSetProperties("dialogs/dialog/transition");

         digester.addSetProperty("dialogs/dialog/transition/property", "name", "value");

         digester.addSetNext("dialogs/dialog/transition",

                             "addTransition", "org.apache.shale.dialog.basic.model.Transition");

         // dialogs/dialog/view

         digester.addObjectCreate("dialogs/dialog/view", "className",

                                  ViewStateImpl.class);

         digester.addSetProperties("dialogs/dialog/view");

         digester.addSetProperty("dialogs/dialog/view/property", "name", "value");

         digester.addSetNext("dialogs/dialog/view",

                             "addState", "org.apache.shale.dialog.basic.model.State");

         // dialogs/dialog/view/transition

         digester.addObjectCreate("dialogs/dialog/view/transition", "className",

                                  TransitionImpl.class);

         digester.addSetProperties("dialogs/dialog/view/transition");

         digester.addSetProperty("dialogs/dialog/view/transition/property", "name", "value");

         digester.addSetNext("dialogs/dialog/view/transition",

                             "addTransition", "org.apache.shale.dialog.basic.model.Transition");

         return digester;

     }

     // -------------------------------------------- Private Rule Implementations

     /**

      * <p>Custom <code>Digester</code> rule to add a dialog.</p>

      */

     static class AddDialogRule extends Rule {

         /**

          * <p>Process the "end" event for this rule.</p>

          *

          * @param namespace XML namespace of this element

          * @param name Name of this element

          *

          * @exception Exception if a processing exception occurs

          */

         public void end(String namespace, String name) throws Exception {

             Dialog dialog = (Dialog) getDigester().peek();

             Map map = (Map) getDigester().peek(1);

             map.put(dialog.getName(), dialog);

         }

     }

 }