framework/src/net/sf/tapestry/AbstractPage.java - tapestry4 - Git at Google

 //
 // Tapestry Web Application Framework
 // Copyright (c) 2000-2002 by Howard Lewis Ship
 //
 // Howard Lewis Ship
 // http://sf.net/projects/tapestry
 // mailto:hship@users.sf.net
 //
 // This library is free software.
 //
 // You may redistribute it and/or modify it under the terms of the GNU
 // Lesser General Public License as published by the Free Software Foundation.
 //
 // Version 2.1 of the license should be included with this distribution in
 // the file LICENSE, as well as License.html. If the license is not
 // included with this distribution, you may find a copy at the FSF web
 // site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
 // Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
 //
 // This library is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied waranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 // Lesser General Public License for more details.
 //

 package net.sf.tapestry;

 import java.io.OutputStream;
 import java.util.EventListener;
 import java.util.Locale;

 import javax.swing.event.EventListenerList;

 import org.apache.log4j.Category;

 import net.sf.tapestry.event.ChangeObserver;
 import net.sf.tapestry.event.PageCleanupListener;
 import net.sf.tapestry.event.PageDetachListener;
 import net.sf.tapestry.event.PageEvent;
 import net.sf.tapestry.event.PageRenderListener;
 import net.sf.tapestry.util.StringSplitter;

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

 public abstract class AbstractPage extends BaseComponent implements IPage
 {
     private static final Category CAT = Category.getInstance(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.  This may
      *  be read, but not changed, but subclasses.
      *
      *  @deprecated this will be removed after 2.1, classes should use {@link #getEngine()}
      *
      **/

     protected IEngine engine;

     /**
      *  The visit object, if any, for the application.  Set inside
      *  {@link #attach(IEngine)} and cleared
      *  by {@link #detach()}.
      *
      **/

     private Object _visit;

     /**
      *  The name of this page.  This may be read, but not changed, by
      *  subclasses.
      *
      *  @deprecated this will be removed after 2.1, classes should use {@link #getName()}
      *
      **/

     protected String name;

     /**
      *  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 PageRenderListener
      *  @see PageDetachListener
      *
      *  @since 1.0.5
      **/

     private EventListenerList _listenerList;

     /**
      *  Implemented in subclasses to provide a particular kind of
      *  response writer (and therefore, a particular kind of
      *  content).
      *
      **/

     abstract public IMarkupWriter getResponseWriter(OutputStream out);

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

     public void detach()
     {
         firePageDetached();

         engine = null;
         _visit = null;
         _changeObserver = null;
         _requestCycle = null;
     }

     public IEngine getEngine()
     {
         return engine;
     }

     public ChangeObserver getChangeObserver()
     {
         return _changeObserver;
     }

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

     public String getExtendedId()
     {
         return name;
     }

     /**
      *  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.getString("AbstractPage.attempt-to-change-locale"));

         _locale = value;
     }

     public String getName()
     {
         return name;
     }

     public IPage getPage()
     {
         return this;
     }

     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 IPageSource} pool based on its
      *  locale matching the engine's locale, they should match
      *  anyway.
      *
      **/

     public void attach(IEngine value)
     {
         if (engine != null)
             CAT.error(this +" attach(" + value + "), but engine = " + engine);

         engine = value;
     }

     /**
      *
      * <ul>
      *  <li>Invokes {@link PageRenderListener#pageBeginRender(PageEvent)}
      *  <li>Invokes {@link #beginResponse(IMarkupWriter, IRequestCycle)}
      *  <li>Invokes {@link IRequestCycle#commitPageChanges()} (if not rewinding)
      *  <li>Invokes {@link #render(IMarkupWriter, IRequestCycle)}
      *  <li>Invokes {@link PageRenderListener#pageEndRender(PageEvent)} (this occurs
      *  even if a previous step throws an exception)
      *
      **/

     public void renderPage(IMarkupWriter writer, IRequestCycle cycle) throws RequestCycleException
     {
         try
         {
             firePageBeginRender();

             beginResponse(writer, cycle);

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

             render(writer, cycle);
         }
         catch (PageRecorderCommitException ex)
         {
             throw new RequestCycleException(ex.getMessage(), null, ex);
         }
         finally
         {
             firePageEndRender();
         }
     }

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

     public void setName(String value)
     {
         if (name != null)
             throw new ApplicationRuntimeException(Tapestry.getString("AbstractPage.attempt-to-change-name"));

         name = value;
     }

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

     public void validate(IRequestCycle cycle) throws RequestCycleException
     {
         // Does nothing.
     }

     /**
      *  Does nothing, subclasses may override as needed.
      *
      *
      **/

     public void beginResponse(IMarkupWriter writer, IRequestCycle cycle) throws RequestCycleException
     {
     }

     public IRequestCycle getRequestCycle()
     {
         return _requestCycle;
     }

     public void setRequestCycle(IRequestCycle value)
     {
         _requestCycle = value;
     }

     /**
      *  Invokes {@link PageCleanupListener#pageCleanup(PageEvent)} on any
      *  listener.
      *
      *  <p>Subclasses may override, but should invoke this implementation.
      *
      **/

     public void cleanupPage()
     {
         firePageCleanup();
     }

     /**
      *  Returns the visit object obtained from the engine via
      *  {@link IEngine#getVisit(IRequestCycle)}.
      *
      **/

     public Object getVisit()
     {
         if (_visit == null)
             _visit = engine.getVisit(_requestCycle);

         return _visit;
     }

     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);
     }

     /**
      *  @seince 2.1-beta-2
      *
      **/

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

     public void addPageRenderListener(PageRenderListener listener)
     {
         addListener(PageRenderListener.class, listener);
     }

     public void addPageCleanupListener(PageCleanupListener listener)
     {
         addListener(PageCleanupListener.class, listener);
     }

     /**
      *  @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 = 0; i < listeners.length; i += 2)
         {
             if (listeners[i] == PageRenderListener.class)
             {
                 PageRenderListener l = (PageRenderListener) 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] == PageRenderListener.class)
             {
                 PageRenderListener l = (PageRenderListener) listeners[i + 1];

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

                 l.pageEndRender(event);
             }
         }
     }
     protected void firePageCleanup()
     {
         if (_listenerList == null)
             return;

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

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

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

                 l.pageCleanup(event);
             }
         }
     }

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

     public void removePageCleanupListener(PageCleanupListener listener)
     {
         removeListener(PageCleanupListener.class, listener);
     }


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

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


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

     public void removePageRenderListener(PageRenderListener listener)
     {
         removeListener(PageRenderListener.class, listener);
     }

 }
	//
	// Tapestry Web Application Framework
	// Copyright (c) 2000-2002 by Howard Lewis Ship
	//
	// Howard Lewis Ship
	// http://sf.net/projects/tapestry
	// mailto:hship@users.sf.net
	//
	// This library is free software.
	//
	// You may redistribute it and/or modify it under the terms of the GNU
	// Lesser General Public License as published by the Free Software Foundation.
	//
	// Version 2.1 of the license should be included with this distribution in
	// the file LICENSE, as well as License.html. If the license is not
	// included with this distribution, you may find a copy at the FSF web
	// site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
	// Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
	//
	// This library is distributed in the hope that it will be useful,
	// but WITHOUT ANY WARRANTY; without even the implied waranty of
	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	// Lesser General Public License for more details.
	//

	package net.sf.tapestry;

	import java.io.OutputStream;
	import java.util.EventListener;
	import java.util.Locale;

	import javax.swing.event.EventListenerList;

	import org.apache.log4j.Category;

	import net.sf.tapestry.event.ChangeObserver;
	import net.sf.tapestry.event.PageCleanupListener;
	import net.sf.tapestry.event.PageDetachListener;
	import net.sf.tapestry.event.PageEvent;
	import net.sf.tapestry.event.PageRenderListener;
	import net.sf.tapestry.util.StringSplitter;

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

	public abstract class AbstractPage extends BaseComponent implements IPage
	{
	private static final Category CAT = Category.getInstance(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. This may
	* be read, but not changed, but subclasses.
	*
	* @deprecated this will be removed after 2.1, classes should use {@link #getEngine()}
	*
	**/

	protected IEngine engine;

	/**
	* The visit object, if any, for the application. Set inside
	* {@link #attach(IEngine)} and cleared
	* by {@link #detach()}.
	*
	**/

	private Object _visit;

	/**
	* The name of this page. This may be read, but not changed, by
	* subclasses.
	*
	* @deprecated this will be removed after 2.1, classes should use {@link #getName()}
	*
	**/

	protected String name;

	/**
	* 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 PageRenderListener
	* @see PageDetachListener
	*
	* @since 1.0.5
	**/

	private EventListenerList _listenerList;

	/**
	* Implemented in subclasses to provide a particular kind of
	* response writer (and therefore, a particular kind of
	* content).
	*
	**/

	abstract public IMarkupWriter getResponseWriter(OutputStream out);

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

	public void detach()
	{
	firePageDetached();

	engine = null;
	_visit = null;
	_changeObserver = null;
	_requestCycle = null;
	}

	public IEngine getEngine()
	{
	return engine;
	}

	public ChangeObserver getChangeObserver()
	{
	return _changeObserver;
	}

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

	public String getExtendedId()
	{
	return name;
	}

	/**
	* 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.getString("AbstractPage.attempt-to-change-locale"));

	_locale = value;
	}

	public String getName()
	{
	return name;
	}

	public IPage getPage()
	{
	return this;
	}

	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 IPageSource} pool based on its
	* locale matching the engine's locale, they should match
	* anyway.
	*
	**/

	public void attach(IEngine value)
	{
	if (engine != null)
	CAT.error(this +" attach(" + value + "), but engine = " + engine);

	engine = value;
	}

	/**
	*
	* <ul>
	* <li>Invokes {@link PageRenderListener#pageBeginRender(PageEvent)}
	* <li>Invokes {@link #beginResponse(IMarkupWriter, IRequestCycle)}
	* <li>Invokes {@link IRequestCycle#commitPageChanges()} (if not rewinding)
	* <li>Invokes {@link #render(IMarkupWriter, IRequestCycle)}
	* <li>Invokes {@link PageRenderListener#pageEndRender(PageEvent)} (this occurs
	* even if a previous step throws an exception)
	*
	**/

	public void renderPage(IMarkupWriter writer, IRequestCycle cycle) throws RequestCycleException
	{
	try
	{
	firePageBeginRender();

	beginResponse(writer, cycle);

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

	render(writer, cycle);
	}
	catch (PageRecorderCommitException ex)
	{
	throw new RequestCycleException(ex.getMessage(), null, ex);
	}
	finally
	{
	firePageEndRender();
	}
	}

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

	public void setName(String value)
	{
	if (name != null)
	throw new ApplicationRuntimeException(Tapestry.getString("AbstractPage.attempt-to-change-name"));

	name = value;
	}

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

	public void validate(IRequestCycle cycle) throws RequestCycleException
	{
	// Does nothing.
	}

	/**
	* Does nothing, subclasses may override as needed.
	*
	*
	**/

	public void beginResponse(IMarkupWriter writer, IRequestCycle cycle) throws RequestCycleException
	{
	}

	public IRequestCycle getRequestCycle()
	{
	return _requestCycle;
	}

	public void setRequestCycle(IRequestCycle value)
	{
	_requestCycle = value;
	}

	/**
	* Invokes {@link PageCleanupListener#pageCleanup(PageEvent)} on any
	* listener.
	*
	* <p>Subclasses may override, but should invoke this implementation.
	*
	**/

	public void cleanupPage()
	{
	firePageCleanup();
	}

	/**
	* Returns the visit object obtained from the engine via
	* {@link IEngine#getVisit(IRequestCycle)}.
	*
	**/

	public Object getVisit()
	{
	if (_visit == null)
	_visit = engine.getVisit(_requestCycle);

	return _visit;
	}

	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);
	}

	/**
	* @seince 2.1-beta-2
	*
	**/

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

	public void addPageRenderListener(PageRenderListener listener)
	{
	addListener(PageRenderListener.class, listener);
	}

	public void addPageCleanupListener(PageCleanupListener listener)
	{
	addListener(PageCleanupListener.class, listener);
	}

	/**
	* @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 = 0; i < listeners.length; i += 2)
	{
	if (listeners[i] == PageRenderListener.class)
	{
	PageRenderListener l = (PageRenderListener) 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] == PageRenderListener.class)
	{
	PageRenderListener l = (PageRenderListener) listeners[i + 1];

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

	l.pageEndRender(event);
	}
	}
	}
	protected void firePageCleanup()
	{
	if (_listenerList == null)
	return;

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

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

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

	l.pageCleanup(event);
	}
	}
	}

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

	public void removePageCleanupListener(PageCleanupListener listener)
	{
	removeListener(PageCleanupListener.class, listener);
	}


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

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


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

	public void removePageRenderListener(PageRenderListener listener)
	{
	removeListener(PageRenderListener.class, listener);
	}

	}