framework/src/net/sf/tapestry/IPageSource.java

//
// 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;

/**
 *  Abstracts the process of loading pages from thier specifications as
 *  well as pooling of pages once loaded.  
 *
 *  <p>If the required page is not available, a page source may use an
 *  instance of {@link IPageLoader} to actually load the
 *  page (and all of its nested components).
 *
 *  @author Howard Lewis Ship
 *  @version $Id$
 * 
 **/

public interface IPageSource
{
	/**
	 *  Gets a given page for the engine.  This may involve using a previously
	 *  loaded page from a pool of available pages, or the page may be loaded as needed.
	 *
	 **/

	public IPage getPage(IEngine engine, String pageName, IMonitor monitor)
		throws PageLoaderException;

	/**
	 *  Invoked after the engine is done with the page
	 *  (typically, after the response to the client has been sent).
	 *  The page is returned to the pool for later reuse.
	 *
	 **/

	public void releasePage(IPage page);

	/**
	 *  Invoked to have the source clear any internal cache.  This is most often
	 *  used when debugging an application.
	 *
	 **/

	public void reset();

	/**
	 *  Gets a field binding for the named field (the name includes the class name
	 *  and the field).  If no such binding exists, then one is created, otherwise
	 *  the existing binding is returned. 
	 *
	 * @since 1.0.2
	 **/

	public IBinding getFieldBinding(String fieldName);

	/**
	 *  Like {@link #getFieldBinding(String)}, except for static bindings.
	 *
	 * @since 1.0.2
	 **/

	public IBinding getStaticBinding(String value);

	/**
	 *  Gets a cached asset.
	 *
	 *  @since 1.0.2
	 *
	 **/

	public IAsset getExternalAsset(String URL);

	/**
	 *  Gets a cached asset.
	 *
	 *  @since 1.0.2
	 *
	 **/

	public IAsset getContextAsset(String assetPath);

	/**
	 *  Gets a cached asset.
	 *
	 *  @since 1.0.2
	 *
	 **/

	public IAsset getPrivateAsset(String resourcePath);
}