============================================================================

                   The Apache Software License, Version 1.1

============================================================================

Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.

Redistribution and use in source and binary forms, with or without modifica-

tion, are permitted provided that the following conditions are met:

1. Redistributions of  source code must  retain the above copyright  notice,

    this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,

    this list of conditions and the following disclaimer in the documentation

    and/or other materials provided with the distribution.

3. The end-user documentation included with the redistribution, if any, must

    include  the following  acknowledgment:  "This product includes  software

    developed  by the  Apache Software Foundation  (http://www.apache.org/)."

    Alternately, this  acknowledgment may  appear in the software itself,  if

    and wherever such third-party acknowledgments normally appear.

4. The names "Apache Cocoon" and  "Apache Software Foundation" must  not  be

    used to  endorse or promote  products derived from  this software without

    prior written permission. For written permission, please contact

    apache@apache.org.

5. Products  derived from this software may not  be called "Apache", nor may

    "Apache" appear  in their name,  without prior written permission  of the

    Apache Software Foundation.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,

INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS  FOR A PARTICULAR  PURPOSE ARE  DISCLAIMED.  IN NO  EVENT SHALL  THE

APACHE SOFTWARE  FOUNDATION  OR ITS CONTRIBUTORS  BE LIABLE FOR  ANY DIRECT,

INDIRECT, INCIDENTAL, SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLU-

DING, BUT NOT LIMITED TO, PROCUREMENT  OF SUBSTITUTE GOODS OR SERVICES; LOSS

OF USE, DATA, OR  PROFITS; OR BUSINESS  INTERRUPTION)  HOWEVER CAUSED AND ON

ANY  THEORY OF LIABILITY,  WHETHER  IN CONTRACT,  STRICT LIABILITY,  OR TORT

(INCLUDING  NEGLIGENCE OR  OTHERWISE) ARISING IN  ANY WAY OUT OF THE  USE OF

THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

This software  consists of voluntary contributions made  by many individuals

on  behalf of the Apache Software  Foundation and was  originally created by

Stefano Mazzocchi  <stefano@apache.org>. For more  information on the Apache

Software Foundation, please see <http://www.apache.org/>.

*/

* This is the action used to propagate parameters into a store using an

* {@link org.apache.cocoon.components.modules.output.OutputModule}. It

* simply propagates given expression. Additionaly it will make all propagated values

* available via returned Map.

*

* <p>Example configuration:</p>

* <pre>

* &lt;map:action type="...." name="...." logger="..."&gt;

*   &lt;output-module name="session-attr"&gt;

*      &lt;!-- optional configuration for output module --&gt;

*   &lt;/output-module&gt;

*   &lt;store-empty-parameters&gt;true&lt;/store-empty-parameters&gt;

*   &lt;defaults&gt;

*     &lt;default name="..." value="...."/&gt;

*     &lt;default name="..." value="..."/&gt;

*   &lt;/defaults&gt;

* &lt;/map:action&gt;

* </pre>

*

* <p>Example use:</p>

* <pre>

* &lt;map:act type="session-propagator"&gt;

*      &lt;paramater name="example" value="{example}"/&gt;

*      &lt;paramater name="example1" value="xxx"/&gt;

*      &lt;parameter name="PropagatorAction:store-empty-parameters" value="true"/&gt;

*      &lt;parameter name="PropagatorAction:output-module" value="session-attr"/&gt;

* &lt;/map:act&gt;

* </pre>

*

* <h3>Configuration</h3>

* <table><tbody>

* <tr>

*  <th>output-module</th>

*  <td>Nested element configuring output to use. Name attribute holds

*      output module hint.</td>

*  <td></td><td>XML</td><td><code>request-attr</code></td>

* </tr>

* <tr>

*  <th>store-empty-parameters</th>

*  <td>Propagate parameters with empty values.</td>

*  <td></td><td>boolean</td><td><code>true</code></td>

* </tr>

* <tr>

*  <th>defaults</th>

*  <td>Parent for default parameters to propagate.</td>

*  <td></td><td>XML</td><td></td>

* </tr>

* <tr>

*  <th>defaults/default</th>

*  <td>Name attribute holds parameter name, value attribute holds

*      parameter value. Will be used when not set on use.</td>

*  <td></td><td>parameter</td><td></td>

* </tr>

* </tbody></table>

*

*<h3>Parameters</h3>

* <table><tbody>

* <tr>

*  <th>PropagatorAction:output-module</th>

*  <td>Alternative output module hint to use. A <code>null</code> configuration

*      will be passed to a module selected this way.</td>

*  <td></td><td>String</td><td>as determined by configuration</td>

* </tr>

* <tr>

*  <th>PropagatorAction:store-empty-parameters</th>

*  <td>Propagate parameters with empty values.</td>

*  <td></td><td>boolean</td><td>as determined by configuration</td>

* </tr>

* <tr>

*  <th>any other</th>

*  <td>Any other parameter will be propagated.</td>

*  <td></td><td>String</td><td></td>

* </tr>

* </tbody></table>

*

* @author <a href="mailto:haul@apache.org">Christian Haul</a>

* @author <a href="mailto:Martin.Man@seznam.cz">Martin Man</a>

* @version CVS $Id: PropagatorAction.java,v 1.2 2003/12/11 03:28:16 crossley Exp $

*/

  extends  ServiceableAction

  implements Configurable, ThreadSafe {

    /** Role name for output modules. */

    private static final String OUTPUT_MODULE_ROLE = OutputModule.ROLE;

   

    /** Selector name for output modules. */

    private static final String OUTPUT_MODULE_SELECTOR = OUTPUT_MODULE_ROLE + "Selector";

    /** Prefix for sitemap parameters targeted at this action. */

  private static final String ACTION_PREFIX = "PropagatorAction:";

    /** Configuration parameter name. */

  private static final String CONFIG_STORE_EMPTY = "store-empty-parameters";

    /** Configuration parameter name. */

  private static final String CONFIG_OUTPUT_MODULE = "output-module";

    /** Should empty parameter values be propagated? */

  private boolean storeEmpty = true;

    /** Configuration object for output module. */

  private Configuration outputConf = null;

   

    /** Name of output module to use. */

  private String outputName = null;

    /** Default output module name. */

  private static final String outputHint = "request-attr"; // default to request attributes

   

    /** List of {@link Entry}s holding default values. */

  private List defaults = null;

     * A private helper holding default parameter entries.

     *

     */

  private class Entry {

    public String key = null;

    public String value = null;

    public Entry(String key, String value) {

      this.key = key;

      this.value = value;

    }

  }

  /*

   *  (non-Javadoc)

   * @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)

   */

  public void configure(Configuration config) throws ConfigurationException {

    this.outputConf = config.getChild(CONFIG_OUTPUT_MODULE);

    this.outputName = this.outputConf.getAttribute("name", outputHint);

    this.storeEmpty =

      config.getChild(CONFIG_STORE_EMPTY).getValueAsBoolean(this.storeEmpty);

    Configuration[] dflts = config.getChild("defaults").getChildren("default");

    if (dflts != null) {

      this.defaults = new ArrayList(dflts.length);

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

        this.defaults.add(

          new Entry(

            dflts[i].getAttribute("name"),

            dflts[i].getAttribute("value")));

      }

    } else {

      this.defaults = new ArrayList(0);

    }

  }

  /**

   * Read parameters and remove configuration for this action.

   *

   * @param param

   * @return

   */

  private Object[] readParameters(Parameters param) {

    String outputName =

      param.getParameter(ACTION_PREFIX + CONFIG_OUTPUT_MODULE, null);

    Boolean storeEmpty =

      new Boolean(

        param.getParameterAsBoolean(

          ACTION_PREFIX + CONFIG_STORE_EMPTY,

          this.storeEmpty));

    param.removeParameter(ACTION_PREFIX + CONFIG_OUTPUT_MODULE);

    param.removeParameter(ACTION_PREFIX + CONFIG_STORE_EMPTY);

    return new Object[] { outputName, storeEmpty };

  }

  /*

   *  (non-Javadoc)

   * @see org.apache.cocoon.acting.Action#act(org.apache.cocoon.environment.Redirector, org.apache.cocoon.environment.SourceResolver, java.util.Map, java.lang.String, org.apache.avalon.framework.parameters.Parameters)

   */

  public Map act(

    Redirector redirector,

    SourceResolver resolver,

    Map objectModel,

    String source,

    Parameters parameters)

    throws Exception {

    // general setup

    OutputModule output = null;

    ServiceSelector outputSelector = null;

    // I don't like this. Have a better idea to return two values.   

    Object[] obj = this.readParameters(parameters);

    String outputName = (String) obj[0];

    boolean storeEmpty = ((Boolean) obj[1]).booleanValue();

    Configuration outputConf = null;

    if (outputName == null) {

      outputName = this.outputName;

      outputConf = this.outputConf;

    }

    Map actionMap = new HashMap();

    try {

      outputSelector =

        (ServiceSelector) this.manager.lookup(OUTPUT_MODULE_SELECTOR);

      if (outputName != null

        && outputSelector != null

        && outputSelector.isSelectable(outputName)) {

        output = (OutputModule) outputSelector.select(outputName);

        String[] names = parameters.getNames();

        // parameters

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

          String sessionParamName = names[i];

          String value = parameters.getParameter(sessionParamName);

          if (storeEmpty || (value != null && !value.equals(""))) {

            if (getLogger().isDebugEnabled()) {

              getLogger().debug(

                "Propagating value "

                  + value

                  + " to output module"

                  + sessionParamName);

            }

            output.setAttribute(

              outputConf,

              objectModel,

              sessionParamName,

              value);

            actionMap.put(sessionParamName, value);

          }

        }

        // defaults, that are not overridden

        for (Iterator i = defaults.iterator(); i.hasNext();) {

          Entry entry = (Entry) i.next();

          if (!actionMap.containsKey(entry.key)) {

            if (getLogger().isDebugEnabled()) {

              getLogger().debug(

                "Propagating default value "

                  + entry.value

                  + " to session attribute "

                  + entry.key);

            }

            output.setAttribute(

              outputConf,

              objectModel,

              entry.key,

              entry.value);

            actionMap.put(entry.key, entry.value);

          }

        }

        output.commit(outputConf, objectModel);

      }

    } catch (Exception e) {

      if (output != null) {

        output.rollback(outputConf, objectModel, e);

      }

      throw e;

    } finally {

      if (outputSelector != null) {

        if (output != null)

          outputSelector.release(output);

        this.manager.release(outputSelector);

      }

    }

    return Collections.unmodifiableMap(actionMap);

  }

}