// 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.annotations.Path;

 import org.apache.tapestry5.ioc.ObjectLocator;

 import org.apache.tapestry5.ioc.Resource;

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

 import org.apache.tapestry5.model.MutableComponentModel;

 import org.apache.tapestry5.services.AssetSource;

 import org.apache.tapestry5.services.ClassTransformation;

 import org.apache.tapestry5.services.InjectionProvider;

 import static java.lang.String.format;

 /**

  * Performs injection of assets, based on the presence of the {@link Path} annotation. This is more useful than the

  * general {@link AssetObjectProvider}, becase relative assets are supported.

  */

 public class AssetInjectionProvider implements InjectionProvider

 {

     private final SymbolSource symbolSource;

     private final AssetSource assetSource;

     public AssetInjectionProvider(SymbolSource symbolSource, AssetSource assetSource)

     {

         this.symbolSource = symbolSource;

         this.assetSource = assetSource;

     }

     public boolean provideInjection(String fieldName, Class fieldType, ObjectLocator locator,

                                     ClassTransformation transformation, MutableComponentModel componentModel)

     {

         Path path = transformation.getFieldAnnotation(fieldName, Path.class);

         if (path == null) return false;

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

         String sourceFieldName = transformation.addInjectedField(AssetSource.class, "assetSource", assetSource);

         String baseResourceFieldName = transformation.addInjectedField(Resource.class, "baseResource",

                                                                        componentModel.getBaseResource());

         String resourcesFieldName = transformation.getResourcesFieldName();

         String statement = format("%s = (%s) %s.getAsset(%s, \"%s\", %s.getLocale());", fieldName, fieldType.getName(),

                                   sourceFieldName, baseResourceFieldName, expanded, resourcesFieldName);

         transformation.extendConstructor(statement);

         transformation.makeReadOnly(fieldName);

         return true;

     }

 }