/***
* Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
* All rights reserved.
*
* 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 br.com.caelum.vraptor.view;
import java.lang.reflect.Method;
import java.util.List;
import net.vidageek.mirror.dsl.Mirror;
import br.com.caelum.vraptor.Result;
import br.com.caelum.vraptor.View;
import br.com.caelum.vraptor.proxy.MethodInvocation;
import br.com.caelum.vraptor.proxy.Proxifier;
import br.com.caelum.vraptor.proxy.SuperMethod;
import br.com.caelum.vraptor.serialization.Serializer;
import br.com.caelum.vraptor.serialization.SerializerBuilder;
import br.com.caelum.vraptor.validator.Message;
import br.com.caelum.vraptor.validator.ValidationException;
/**
* Default implementation for ValidationViewsFactory
*
* If you want to extend this behavior use:
* @Component
* public class MyValidatorViewsFactory extends DefaultValidationViewsFactory {
* //delegate constructor
* @Override
* public <T extends View> T instanceFor(Class<T> view, List<Message> errors) {
* //return my own Validation view version or
* return super.instanceFor(view, errors);
* }
* }
* @author Lucas Cavalcanti
* @author Pedro Matiello
*/
public class DefaultValidationViewsFactory implements ValidationViewsFactory {
private final Result result;
private final Proxifier proxifier;
public DefaultValidationViewsFactory(Result result, Proxifier proxifier) {
this.result = result;
this.proxifier = proxifier;
}
public <T extends View> T instanceFor(final Class<T> view, final List<Message> errors) {
if (view.equals(EmptyResult.class)) {
throw new ValidationException(errors);
}
return proxifier.proxify(view, throwValidationErrorOnFinalMethods(view, errors, result.use(view)));
}
private <T> MethodInvocation<T> throwValidationErrorOnFinalMethods(final Class<T> view, final List<Message> errors,
final T viewInstance) {
return new MethodInvocation<T>() {
public Object intercept(T proxy, Method method, Object[] args, SuperMethod superMethod) {
final Object instance = new Mirror().on(viewInstance).invoke().method(method).withArgs(args);
if (method.getReturnType() == void.class) {
throw new ValidationException(errors);
}
if (view.isAssignableFrom(method.getReturnType())) {
return proxy;
}
if (args.length > 0 && args[0] instanceof Class<?>) {
return proxifier.proxify((Class<?>) args[0], throwValidationExceptionOnFirstInvocation(errors, instance));
}
if (Serializer.class.isAssignableFrom(method.getReturnType())
|| SerializerBuilder.class.isAssignableFrom(method.getReturnType())) {
return proxifier.proxify(SerializerBuilder.class,
throwValidationErrorOnFinalMethods(SerializerBuilder.class, errors, SerializerBuilder.class.cast(instance)));
}
throw new ResultException("It's not possible to create a validation version of " + method + ". You must provide a Custom Validation version of your class, or inform this corner case to VRaptor developers");
}
};
}
private <T> MethodInvocation<T> throwValidationExceptionOnFirstInvocation(final List<Message> errors,
final T instance) {
return new MethodInvocation<T>() {
public Object intercept(Object proxy, Method method, Object[] args, SuperMethod superMethod) {
new Mirror().on(instance).invoke().method(method).withArgs(args);
throw new ValidationException(errors);
}
};
}
}