tapestry/tapestry-framework/src/java/org/apache/tapestry/AbstractPage.java - tapestry4 - Git at Google

 // Copyright 2004, 2005 The Apache Software Foundation
 //
 // 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 org.apache.tapestry;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hivemind.ApplicationRuntimeException;
 import org.apache.tapestry.engine.NullWriter;
 import org.apache.tapestry.event.*;
 import org.apache.tapestry.services.ResponseBuilder;
 import org.apache.tapestry.util.StringSplitter;

 import javax.swing.event.EventListenerList;
 import java.util.EventListener;
 import java.util.Locale;

 /**
  * Abstract base class implementing the {@link IPage}interface.
  *
  * @author Howard Lewis Ship, David Solis
  * @since 0.2.9
  */

 public abstract class AbstractPage extends BaseComponent implements IPage
 {
     private static final Log LOG = LogFactory.getLog(AbstractPage.class);

     /**
      * Object to be notified when a observered property changes. Observered properties are the ones
      * that will be persisted between request cycles. Unobserved properties are reconstructed.
      */

     private ChangeObserver _changeObserver;

     /**
      * The {@link IEngine}the page is currently attached to.
      */

     private IEngine _engine;

     /**
      * The qualified name of the page, which may be prefixed by the namespace.
      *
      * @since 2.3
      */

     private String _pageName;

     /**
      * Set when the page is attached to the engine.
      */

     private IRequestCycle _requestCycle;

     /**
      * The locale of the page, initially determined from the {@link IEngine engine}.
      */

     private Locale _locale;

     /**
      * A list of listeners for the page.
      *
      * @see PageBeginRenderListener
      * @see PageEndRenderListener
      * @see PageDetachListener
      * @since 1.0.5
      */

     private EventListenerList _listenerList;

     /**
      * The output encoding to be used when rendering this page. This value is cached from the
      * engine.
      *
      * @since 3.0
      */
     private String _outputEncoding;

     /**
      * Used to dynamically include script content automatically for form specific includes.
      * @since 4.1.2
      */
     private boolean _hasForms;

     /**
      * Dynamically causes widget dojo layer to be included if set to true.
      * @since 4.1.2.
      */
     private boolean _hasWidgets;

     /**
      * Standard constructor. Does nothing.
      *
      * @since 2.2
      */

     public AbstractPage()
     {
     }

     /**
      * Prepares the page to be returned to the pool.
      * <ul>
      * <li>Clears the changeObserved property
      * <li>Invokes {@link PageDetachListener#pageDetached(PageEvent)}on all listeners
      * <li>Clears the engine and requestCycle properties
      * </ul>
      * <p>
      * Subclasses may override this method, but must invoke this implementation (usually, last).
      *
      * @see PageDetachListener
      */

     public void detach()
     {
         Tapestry.addMethodInvocation(Tapestry.ABSTRACTPAGE_DETACH_METHOD_ID);

         // Do this first,so that any changes to persistent properties do not
         // cause errors.

         _changeObserver = null;

         firePageDetached();

         _engine = null;
         _requestCycle = null;
     }

     public IEngine getEngine()
     {
         return _engine;
     }

     public ChangeObserver getChangeObserver()
     {
         return _changeObserver;
     }

     /**
      * Returns the name of the page.
      */

     public String getExtendedId()
     {
         return _pageName;
     }

     /**
      * Pages always return null for idPath.
      */

     public String getIdPath()
     {
         return null;
     }

     /**
      * Returns the locale for the page, which may be null if the locale is not known (null
      * corresponds to the "default locale").
      */

     public Locale getLocale()
     {
         return _locale;
     }

     public void setLocale(Locale value)
     {
         if (_locale != null)
             throw new ApplicationRuntimeException(Tapestry
                     .getMessage("AbstractPage.attempt-to-change-locale"));

         _locale = value;
     }

     public IComponent getNestedComponent(String path)
     {
         StringSplitter splitter;
         IComponent current;
         String[] elements;
         int i;

         if (path == null)
             return this;

         splitter = new StringSplitter('.');
         current = this;

         elements = splitter.splitToArray(path);
         for (i = 0; i < elements.length; i++)
         {
             current = current.getComponent(elements[i]);
         }

         return current;

     }

     /**
      * Called by the {@link IEngine engine} to attach the page to itself. Does <em>not</em> change
      * the locale, but since a page is selected from the
      * {@link org.apache.tapestry.engine.IPageSource} pool based on its locale matching the engine's
      * locale, they should match anyway.
      */

     public void attach(IEngine engine, IRequestCycle cycle)
     {
         if (_engine != null)
             LOG.error(this + " attach(" + engine + "), but engine = " + _engine);

         _engine = engine;
         _requestCycle = cycle;
     }

     /**
      * Renders the page.
      * <ul>
      * <li>Invokes {@link PageBeginRenderListener#pageBeginRender(PageEvent)}
      * <li>Invokes {@link #beginPageRender()}
      * <li>Invokes {@link IRequestCycle#commitPageChanges()}(if not rewinding)
      * <li>Invokes {@link #render(IMarkupWriter, IRequestCycle)}
      * <li>Invokes {@link PageEndRenderListener#pageEndRender(PageEvent)}(this occurs even if a
      * previous step throws an exception)
      * </ul>
      */

     public void renderPage(ResponseBuilder builder, IRequestCycle cycle)
     {
         try
         {
             firePageBeginRender();

             if (!cycle.isRewinding())
                 cycle.commitPageChanges();

             builder.render(cycle.isRewinding() ? NullWriter.getSharedInstance() : null, this, cycle);
         }
         finally
         {
             firePageEndRender();
         }
     }

     public void setChangeObserver(ChangeObserver value)
     {
         _changeObserver = value;
     }

     /** @since 3.0 * */

     public void setPageName(String pageName)
     {
         if (_pageName != null)
             throw new ApplicationRuntimeException(Tapestry
                     .getMessage("AbstractPage.attempt-to-change-name"));

         _pageName = pageName;
     }

     /**
      * By default, pages are not protected and this method does nothing.
      */

     public void validate(IRequestCycle cycle)
     {
         Tapestry.addMethodInvocation(Tapestry.ABSTRACTPAGE_VALIDATE_METHOD_ID);

         firePageValidate();
     }

     public IRequestCycle getRequestCycle()
     {
         return _requestCycle;
     }

     public void addPageDetachListener(PageDetachListener listener)
     {
         addListener(PageDetachListener.class, listener);
     }

     private void addListener(Class listenerClass, EventListener listener)
     {
         if (_listenerList == null)
             _listenerList = new EventListenerList();

         _listenerList.add(listenerClass, listener);
     }

     /**
      * @since 2.1-beta-2
      */

     private void removeListener(Class listenerClass, EventListener listener)
     {
         if (_listenerList != null)
             _listenerList.remove(listenerClass, listener);
     }

     /** @since 4.0 */
     public void addPageBeginRenderListener(PageBeginRenderListener listener)
     {
         addListener(PageBeginRenderListener.class, listener);
     }

     /** @since 4.0 */
     public void addPageEndRenderListener(PageEndRenderListener listener)
     {
         addListener(PageEndRenderListener.class, listener);
     }

     /** @since 4.0 */
     public void removePageBeginRenderListener(PageBeginRenderListener listener)
     {
         removeListener(PageBeginRenderListener.class, listener);
     }

     /** @since 4.0 */
     public void removePageEndRenderListener(PageEndRenderListener listener)
     {
         removeListener(PageEndRenderListener.class, listener);
     }

     /**
      * @since 4.0
      */

     public void firePageAttached()
     {
         if (_listenerList == null)
             return;

         PageEvent event = null;
         Object[] listeners = _listenerList.getListenerList();

         for(int i = listeners.length-2; i >= 0; i -= 2)
         {
             if (listeners[i] == PageAttachListener.class)
             {
                 PageAttachListener l = (PageAttachListener) listeners[i + 1];

                 if (event == null)
                     event = new PageEvent(this, _requestCycle);

                 l.pageAttached(event);
             }
         }
     }

     /**
      * @since 1.0.5
      */

     protected void firePageDetached()
     {
         if (_listenerList == null)
             return;

         PageEvent event = null;
         Object[] listeners = _listenerList.getListenerList();

         for (int i = 0; i < listeners.length; i += 2)
         {
             if (listeners[i] == PageDetachListener.class)
             {
                 PageDetachListener l = (PageDetachListener) listeners[i + 1];

                 if (event == null)
                     event = new PageEvent(this, _requestCycle);

                 l.pageDetached(event);
             }
         }
     }

     /**
      * @since 1.0.5
      */

     protected void firePageBeginRender()
     {
         if (_listenerList == null)
             return;

         PageEvent event = null;
         Object[] listeners = _listenerList.getListenerList();

         for(int i = listeners.length-2; i >= 0; i -= 2)
         {
             if (listeners[i] == PageBeginRenderListener.class)
             {
                 PageBeginRenderListener l = (PageBeginRenderListener)listeners[i + 1];

                 if (event == null)
                     event = new PageEvent(this, _requestCycle);

                 l.pageBeginRender(event);
             }
         }
     }

     /**
      * @since 1.0.5
      */

     protected void firePageEndRender()
     {
         if (_listenerList == null)
             return;

         PageEvent event = null;
         Object[] listeners = _listenerList.getListenerList();

         for (int i = 0; i < listeners.length; i += 2)
         {
             if (listeners[i] == PageEndRenderListener.class)
             {
                 PageEndRenderListener l = (PageEndRenderListener) listeners[i + 1];

                 if (event == null)
                     event = new PageEvent(this, _requestCycle);

                 l.pageEndRender(event);
             }
         }
     }

     /**
      * @since 2.1-beta-2
      */

     public void removePageDetachListener(PageDetachListener listener)
     {
         removeListener(PageDetachListener.class, listener);
     }

     /** @since 2.2 * */

     public void beginPageRender()
     {
         firePageBeginRender();
     }

     /** @since 2.2 * */

     public void endPageRender()
     {
         firePageEndRender();
     }

     protected void cleanupAfterRender(IRequestCycle cycle)
     {
     }

     /** @since 3.0 * */

     public String getPageName()
     {
         return _pageName;
     }

     public void addPageValidateListener(PageValidateListener listener)
     {
         addListener(PageValidateListener.class, listener);
     }

     public void removePageValidateListener(PageValidateListener listener)
     {
         removeListener(PageValidateListener.class, listener);
     }

     /** @since 4.0 */
     public void addPageAttachListener(PageAttachListener listener)
     {
         addListener(PageAttachListener.class, listener);
     }

     /** @since 4.0 */
     public void removePageAttachListener(PageAttachListener listener)
     {
         removeListener(PageAttachListener.class, listener);
     }

     protected void firePageValidate()
     {
         if (_listenerList == null)
             return;

         PageEvent event = null;
         Object[] listeners = _listenerList.getListenerList();

         for (int i = 0; i < listeners.length; i += 2)
         {
             if (listeners[i] == PageValidateListener.class)
             {
                 PageValidateListener l = (PageValidateListener) listeners[i + 1];

                 if (event == null)
                     event = new PageEvent(this, _requestCycle);

                 l.pageValidate(event);
             }
         }
     }

     /**
      * Returns the output encoding to be used when rendering this page. This value is usually cached
      * from the Engine.
      *
      * @since 3.0
      */
     protected String getOutputEncoding()
     {
         if (_outputEncoding == null)
             _outputEncoding = getEngine().getOutputEncoding();

         return _outputEncoding;
     }

     public boolean hasFormComponents()
     {
         return _hasForms;
     }

     public void setHasFormComponents(boolean value)
     {
         _hasForms = value;
     }

     public boolean hasWidgets()
     {
         return _hasWidgets;
     }

     public void setHasWidgets(boolean value)
     {
         _hasWidgets = value;
     }
 }
	// Copyright 2004, 2005 The Apache Software Foundation
	//
	// 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 org.apache.tapestry;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.hivemind.ApplicationRuntimeException;
	import org.apache.tapestry.engine.NullWriter;
	import org.apache.tapestry.event.*;
	import org.apache.tapestry.services.ResponseBuilder;
	import org.apache.tapestry.util.StringSplitter;

	import javax.swing.event.EventListenerList;
	import java.util.EventListener;
	import java.util.Locale;

	/**
	* Abstract base class implementing the {@link IPage}interface.
	*
	* @author Howard Lewis Ship, David Solis
	* @since 0.2.9
	*/

	public abstract class AbstractPage extends BaseComponent implements IPage
	{
	private static final Log LOG = LogFactory.getLog(AbstractPage.class);

	/**
	* Object to be notified when a observered property changes. Observered properties are the ones
	* that will be persisted between request cycles. Unobserved properties are reconstructed.
	*/

	private ChangeObserver _changeObserver;

	/**
	* The {@link IEngine}the page is currently attached to.
	*/

	private IEngine _engine;

	/**
	* The qualified name of the page, which may be prefixed by the namespace.
	*
	* @since 2.3
	*/

	private String _pageName;

	/**
	* Set when the page is attached to the engine.
	*/

	private IRequestCycle _requestCycle;

	/**
	* The locale of the page, initially determined from the {@link IEngine engine}.
	*/

	private Locale _locale;

	/**
	* A list of listeners for the page.
	*
	* @see PageBeginRenderListener
	* @see PageEndRenderListener
	* @see PageDetachListener
	* @since 1.0.5
	*/

	private EventListenerList _listenerList;

	/**
	* The output encoding to be used when rendering this page. This value is cached from the
	* engine.
	*
	* @since 3.0
	*/
	private String _outputEncoding;

	/**
	* Used to dynamically include script content automatically for form specific includes.
	* @since 4.1.2
	*/
	private boolean _hasForms;

	/**
	* Dynamically causes widget dojo layer to be included if set to true.
	* @since 4.1.2.
	*/
	private boolean _hasWidgets;

	/**
	* Standard constructor. Does nothing.
	*
	* @since 2.2
	*/

	public AbstractPage()
	{
	}

	/**
	* Prepares the page to be returned to the pool.
	* <ul>
	* <li>Clears the changeObserved property
	* <li>Invokes {@link PageDetachListener#pageDetached(PageEvent)}on all listeners
	* <li>Clears the engine and requestCycle properties
	* </ul>
	* <p>
	* Subclasses may override this method, but must invoke this implementation (usually, last).
	*
	* @see PageDetachListener
	*/

	public void detach()
	{
	Tapestry.addMethodInvocation(Tapestry.ABSTRACTPAGE_DETACH_METHOD_ID);

	// Do this first,so that any changes to persistent properties do not
	// cause errors.

	_changeObserver = null;

	firePageDetached();

	_engine = null;
	_requestCycle = null;
	}

	public IEngine getEngine()
	{
	return _engine;
	}

	public ChangeObserver getChangeObserver()
	{
	return _changeObserver;
	}

	/**
	* Returns the name of the page.
	*/

	public String getExtendedId()
	{
	return _pageName;
	}

	/**
	* Pages always return null for idPath.
	*/

	public String getIdPath()
	{
	return null;
	}

	/**
	* Returns the locale for the page, which may be null if the locale is not known (null
	* corresponds to the "default locale").
	*/

	public Locale getLocale()
	{
	return _locale;
	}

	public void setLocale(Locale value)
	{
	if (_locale != null)
	throw new ApplicationRuntimeException(Tapestry
	.getMessage("AbstractPage.attempt-to-change-locale"));

	_locale = value;
	}

	public IComponent getNestedComponent(String path)
	{
	StringSplitter splitter;
	IComponent current;
	String[] elements;
	int i;

	if (path == null)
	return this;

	splitter = new StringSplitter('.');
	current = this;

	elements = splitter.splitToArray(path);
	for (i = 0; i < elements.length; i++)
	{
	current = current.getComponent(elements[i]);
	}

	return current;

	}

	/**
	* Called by the {@link IEngine engine} to attach the page to itself. Does <em>not</em> change
	* the locale, but since a page is selected from the
	* {@link org.apache.tapestry.engine.IPageSource} pool based on its locale matching the engine's
	* locale, they should match anyway.
	*/

	public void attach(IEngine engine, IRequestCycle cycle)
	{
	if (_engine != null)
	LOG.error(this + " attach(" + engine + "), but engine = " + _engine);

	_engine = engine;
	_requestCycle = cycle;
	}

	/**
	* Renders the page.
	* <ul>
	* <li>Invokes {@link PageBeginRenderListener#pageBeginRender(PageEvent)}
	* <li>Invokes {@link #beginPageRender()}
	* <li>Invokes {@link IRequestCycle#commitPageChanges()}(if not rewinding)
	* <li>Invokes {@link #render(IMarkupWriter, IRequestCycle)}
	* <li>Invokes {@link PageEndRenderListener#pageEndRender(PageEvent)}(this occurs even if a
	* previous step throws an exception)
	* </ul>
	*/

	public void renderPage(ResponseBuilder builder, IRequestCycle cycle)
	{
	try
	{
	firePageBeginRender();

	if (!cycle.isRewinding())
	cycle.commitPageChanges();

	builder.render(cycle.isRewinding() ? NullWriter.getSharedInstance() : null, this, cycle);
	}
	finally
	{
	firePageEndRender();
	}
	}

	public void setChangeObserver(ChangeObserver value)
	{
	_changeObserver = value;
	}

	/** @since 3.0 * */

	public void setPageName(String pageName)
	{
	if (_pageName != null)
	throw new ApplicationRuntimeException(Tapestry
	.getMessage("AbstractPage.attempt-to-change-name"));

	_pageName = pageName;
	}

	/**
	* By default, pages are not protected and this method does nothing.
	*/

	public void validate(IRequestCycle cycle)
	{
	Tapestry.addMethodInvocation(Tapestry.ABSTRACTPAGE_VALIDATE_METHOD_ID);

	firePageValidate();
	}

	public IRequestCycle getRequestCycle()
	{
	return _requestCycle;
	}

	public void addPageDetachListener(PageDetachListener listener)
	{
	addListener(PageDetachListener.class, listener);
	}

	private void addListener(Class listenerClass, EventListener listener)
	{
	if (_listenerList == null)
	_listenerList = new EventListenerList();

	_listenerList.add(listenerClass, listener);
	}

	/**
	* @since 2.1-beta-2
	*/

	private void removeListener(Class listenerClass, EventListener listener)
	{
	if (_listenerList != null)
	_listenerList.remove(listenerClass, listener);
	}

	/** @since 4.0 */
	public void addPageBeginRenderListener(PageBeginRenderListener listener)
	{
	addListener(PageBeginRenderListener.class, listener);
	}

	/** @since 4.0 */
	public void addPageEndRenderListener(PageEndRenderListener listener)
	{
	addListener(PageEndRenderListener.class, listener);
	}

	/** @since 4.0 */
	public void removePageBeginRenderListener(PageBeginRenderListener listener)
	{
	removeListener(PageBeginRenderListener.class, listener);
	}

	/** @since 4.0 */
	public void removePageEndRenderListener(PageEndRenderListener listener)
	{
	removeListener(PageEndRenderListener.class, listener);
	}

	/**
	* @since 4.0
	*/

	public void firePageAttached()
	{
	if (_listenerList == null)
	return;

	PageEvent event = null;
	Object[] listeners = _listenerList.getListenerList();

	for(int i = listeners.length-2; i >= 0; i -= 2)
	{
	if (listeners[i] == PageAttachListener.class)
	{
	PageAttachListener l = (PageAttachListener) listeners[i + 1];

	if (event == null)
	event = new PageEvent(this, _requestCycle);

	l.pageAttached(event);
	}
	}
	}

	/**
	* @since 1.0.5
	*/

	protected void firePageDetached()
	{
	if (_listenerList == null)
	return;

	PageEvent event = null;
	Object[] listeners = _listenerList.getListenerList();

	for (int i = 0; i < listeners.length; i += 2)
	{
	if (listeners[i] == PageDetachListener.class)
	{
	PageDetachListener l = (PageDetachListener) listeners[i + 1];

	if (event == null)
	event = new PageEvent(this, _requestCycle);

	l.pageDetached(event);
	}
	}
	}

	/**
	* @since 1.0.5
	*/

	protected void firePageBeginRender()
	{
	if (_listenerList == null)
	return;

	PageEvent event = null;
	Object[] listeners = _listenerList.getListenerList();

	for(int i = listeners.length-2; i >= 0; i -= 2)
	{
	if (listeners[i] == PageBeginRenderListener.class)
	{
	PageBeginRenderListener l = (PageBeginRenderListener)listeners[i + 1];

	if (event == null)
	event = new PageEvent(this, _requestCycle);

	l.pageBeginRender(event);
	}
	}
	}

	/**
	* @since 1.0.5
	*/

	protected void firePageEndRender()
	{
	if (_listenerList == null)
	return;

	PageEvent event = null;
	Object[] listeners = _listenerList.getListenerList();

	for (int i = 0; i < listeners.length; i += 2)
	{
	if (listeners[i] == PageEndRenderListener.class)
	{
	PageEndRenderListener l = (PageEndRenderListener) listeners[i + 1];

	if (event == null)
	event = new PageEvent(this, _requestCycle);

	l.pageEndRender(event);
	}
	}
	}

	/**
	* @since 2.1-beta-2
	*/

	public void removePageDetachListener(PageDetachListener listener)
	{
	removeListener(PageDetachListener.class, listener);
	}

	/** @since 2.2 * */

	public void beginPageRender()
	{
	firePageBeginRender();
	}

	/** @since 2.2 * */

	public void endPageRender()
	{
	firePageEndRender();
	}

	protected void cleanupAfterRender(IRequestCycle cycle)
	{
	}

	/** @since 3.0 * */

	public String getPageName()
	{
	return _pageName;
	}

	public void addPageValidateListener(PageValidateListener listener)
	{
	addListener(PageValidateListener.class, listener);
	}

	public void removePageValidateListener(PageValidateListener listener)
	{
	removeListener(PageValidateListener.class, listener);
	}

	/** @since 4.0 */
	public void addPageAttachListener(PageAttachListener listener)
	{
	addListener(PageAttachListener.class, listener);
	}

	/** @since 4.0 */
	public void removePageAttachListener(PageAttachListener listener)
	{
	removeListener(PageAttachListener.class, listener);
	}

	protected void firePageValidate()
	{
	if (_listenerList == null)
	return;

	PageEvent event = null;
	Object[] listeners = _listenerList.getListenerList();

	for (int i = 0; i < listeners.length; i += 2)
	{
	if (listeners[i] == PageValidateListener.class)
	{
	PageValidateListener l = (PageValidateListener) listeners[i + 1];

	if (event == null)
	event = new PageEvent(this, _requestCycle);

	l.pageValidate(event);
	}
	}
	}

	/**
	* Returns the output encoding to be used when rendering this page. This value is usually cached
	* from the Engine.
	*
	* @since 3.0
	*/
	protected String getOutputEncoding()
	{
	if (_outputEncoding == null)
	_outputEncoding = getEngine().getOutputEncoding();

	return _outputEncoding;
	}

	public boolean hasFormComponents()
	{
	return _hasForms;
	}

	public void setHasFormComponents(boolean value)
	{
	_hasForms = value;
	}

	public boolean hasWidgets()
	{
	return _hasWidgets;
	}

	public void setHasWidgets(boolean value)
	{
	_hasWidgets = value;
	}
	}