// Copyright 2006, 2008, 2009 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.tapestry5;

 import org.apache.tapestry5.ioc.Resource;

 /**

  * An Asset is any kind of resource that can be exposed to the client web browser. Although quite often an Asset is a

  * resource in a web application's context folder, within Tapestry, Assets may also be resources on the classpath (i.e.,

  * packaged inside JARs).

  * <p/>

  * An Asset's toString() will return the URL for the resource (the same value as {@link #toClientURL()}).

  * <p/>

  * Release 5.1.0.0 introduced {@link org.apache.tapestry5.Asset2}, which extends this interface with an additional

  * method.

  */

 public interface Asset

 {

     /**

      * Returns a URL that can be passed, unchanged, to the client in order for it to access the resource. The same value

      * is returned from <code>toString()</code>.

      * <p/>

      * Tapestry's built-in asset types (context and classpath) always incorporate a version number as part of the path,

      * and alternate implementations are encouraged to do so as well. In addition, Tapestry ensures that context and

      * classpath assets have a far-future expires header (to ensure aggresive caching by the client).

      * <p/>

      */

     String toClientURL();

     /**

      * Returns the underlying Resource for the Asset.

      */

     Resource getResource();

 }