// Copyright 2006, 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.transform;

 import org.apache.tapestry5.annotations.InjectContainer;

 import org.apache.tapestry5.ioc.util.BodyBuilder;

 import org.apache.tapestry5.model.MutableComponentModel;

 import org.apache.tapestry5.runtime.Component;

 import org.apache.tapestry5.services.ClassTransformation;

 import org.apache.tapestry5.services.ComponentClassTransformWorker;

 import org.apache.tapestry5.services.TransformConstants;

 import java.util.List;

 /**

  * Identifies the {@link org.apache.tapestry5.annotations.InjectContainer} annotation and adds code to initialize it to

  * the core component.

  */

 public class InjectContainerWorker implements ComponentClassTransformWorker

 {

     public void transform(ClassTransformation transformation, MutableComponentModel model)

     {

         List<String> names = transformation.findFieldsWithAnnotation(InjectContainer.class);

         if (names.isEmpty())

             return;

         // I can't imagine a scenario where a component would have more than one

         // field with InjectComponent, but that's the way these APIs work, lists of names.

         BodyBuilder builder = new BodyBuilder();

         builder.begin();

         builder.addln("%s container = %s.getContainer();", Component.class.getName(), transformation

                 .getResourcesFieldName());

         for (String fieldName : names)

         {

             InjectContainer annotation = transformation.getFieldAnnotation(

                     fieldName,

                     InjectContainer.class);

             transformation.claimField(fieldName, annotation);

             String fieldType = transformation.getFieldType(fieldName);

             builder.addln("try");

             builder.begin();

             builder.addln("this.%s = (%s) container;", fieldName, fieldType);

             builder.end();

             builder.addln("catch (ClassCastException ex)");

             builder.begin();

             builder.addln(

                     "String message = %s.buildCastExceptionMessage(container, \"%s.%s\", \"%s\");",

                     InjectContainerWorker.class.getName(),

                     model.getComponentClassName(),

                     fieldName,

                     fieldType);

             builder.addln("throw new RuntimeException(message, ex);");

             builder.end();

             transformation.makeReadOnly(fieldName);

         }

         builder.end();

         transformation.extendMethod(TransformConstants.CONTAINING_PAGE_DID_LOAD_SIGNATURE, builder

                 .toString());

     }

     public static String buildCastExceptionMessage(Component component, String fieldName,

                                                    String fieldType)

     {

         return TransformMessages.componentNotAssignableToField(component, fieldName, fieldType);

     }

 }