framework/src/net/sf/tapestry/IAsset.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;

import java.io.InputStream;

/**
 *  Representation of a asset (GIF, JPEG, etc.) that may be owned by a
 *  {@link IComponent}.
 *
 *  <p>Assets may be completely external (i.e., on some other web site), 
 *  contained by the {@link javax.servlet.ServletContext},  
 *  or stored somewhere in the classpath.
 *
 *  <p>In the latter two cases, the resource may be localized.
 *
 *  @author Howard Lewis Ship
 *  @version $Id$
 *
 **/

public interface IAsset
{
    /**
     *  Returns a URL for the asset, ready to be inserted into the output HTML.
     *  If the asset can be localized, the localized version (matching the
     *  {@link java.util.Locale} of the current {@link IPage page}) is returned.
     *
     **/

    public String buildURL(IRequestCycle cycle);

    /**
     *  Accesses the localized version of the resource (if possible) and returns it as
     *  an input stream.  A version of the resource localized to the
     *  current {@link IPage page} is returned.
     *
     **/

    public InputStream getResourceAsStream(IRequestCycle cycle) throws ResourceUnavailableException;
}