// Copyright 2007, 2008 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.internal.services;

 import org.apache.tapestry5.Asset;

 import org.apache.tapestry5.annotations.Path;

 import org.apache.tapestry5.ioc.AnnotationProvider;

 import org.apache.tapestry5.ioc.ObjectLocator;

 import org.apache.tapestry5.ioc.ObjectProvider;

 import org.apache.tapestry5.ioc.services.Builtin;

 import org.apache.tapestry5.ioc.services.SymbolSource;

 import org.apache.tapestry5.ioc.services.TypeCoercer;

 import org.apache.tapestry5.services.AssetSource;

 import org.apache.tapestry5.services.Core;

 /**

  * Exposes assets (in the current locale). The Inject annotation must be supplemented by a {@link Path} annotation, to

  * identify what asset to be injected.

  */

 public class AssetObjectProvider implements ObjectProvider

 {

     private final AssetSource source;

     private final TypeCoercer typeCoercer;

     private final SymbolSource symbolSource;

     public AssetObjectProvider(@Core AssetSource source,

                                @Builtin TypeCoercer typeCoercer,

                                @Builtin SymbolSource symbolSource)

     {

         this.source = source;

         this.typeCoercer = typeCoercer;

         this.symbolSource = symbolSource;

     }

     /**

      * Provides the asset. If the expression does not identify an asset domain, with a prefix, it is assumed to be a

      * path on the classpath, relative to the root of the classpath.

      *

      * @param objectType the type of object (which must be Object or Asset)

      * @param locator    not used

      */

     public <T> T provide(Class<T> objectType, AnnotationProvider annotationProvider, ObjectLocator locator)

     {

         Path path = annotationProvider.getAnnotation(Path.class);

         if (path == null) return null;

         String expanded = symbolSource.expandSymbols(path.value());

         Asset asset = source.getAsset(null, expanded, null);

         return typeCoercer.coerce(asset, objectType);

     }

 }