DynamicParamValueProducer.java

/*
 * Copyright 2017 OmniFaces
 *
 * 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.omnifaces.cdi.param;

import static java.util.Arrays.asList;
import static java.util.Collections.emptySet;
import static org.omnifaces.util.Beans.getCurrentInjectionPoint;

import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import javax.enterprise.context.Dependent;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.Typed;
import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.InjectionPoint;
import javax.enterprise.inject.spi.PassivationCapable;
import javax.enterprise.util.AnnotationLiteral;
import javax.faces.convert.Converter;
import javax.faces.validator.Validator;

import org.omnifaces.cdi.Param;

/**
 * Dynamic CDI producer used to work around CDI's restriction to create true generic producers.
 * <p>
 * This dynamic producer calls through to the "real" producer for <code>@</code>{@link Param}
 * annotated injection points.
 *
 * @see ParamExtension
 * @see ParamProducer
 *
 * @since 2.0
 * @author Arjan Tijms
 *
 */
@Typed
public class DynamicParamValueProducer implements Bean<Object>, PassivationCapable {

	private Set<Type> types;

	public DynamicParamValueProducer(Type type) {
		types = new HashSet<>(asList(type, Object.class));
	}

	@Override
	public Class<?> getBeanClass() {
		return ParamProducer.class;
	}

	@Override
	public Set<Type> getTypes() {
		return types;
	}

	@Override
	public Object create(CreationalContext<Object> creationalContext) {
		InjectionPoint injectionPoint = getCurrentInjectionPoint(creationalContext);
		ParamValue<?> paramValue = new ParamProducer().produce(injectionPoint);
		return paramValue.getValue();
	}

	@Override
	public Set<Annotation> getQualifiers() {
		return Collections.singleton((Annotation) new DefaultParamAnnotationLiteral());
	}

	@Override
	public Class<? extends Annotation> getScope() {
		return Dependent.class;
	}

	@Override
	public Set<Class<? extends Annotation>> getStereotypes() {
		return emptySet();
	}

	@Override
	public Set<InjectionPoint> getInjectionPoints() {
		return emptySet();
	}

	@Override
	public boolean isAlternative() {
		return false;
	}

	@Override
	public boolean isNullable() {
		return false;
	}

	@Override
	public String getName() {
		return null;
	}

	@Override
	public void destroy(Object instance, CreationalContext<Object> creationalContext) {
		// NOOP
	}

	@Override
	public String getId() {
		return DynamicParamValueProducer.class.getName() + "_" + (types != null ? types.toString() : "");
	}

	@SuppressWarnings("all")
	public static class DefaultParamAnnotationLiteral extends AnnotationLiteral<Param> implements Param {
		private static final long serialVersionUID = 1L;

		private static final String[] EMPTY_STRING_ARRAY = {};
		private static final Class<? extends Validator>[] EMPTY_VALIDATOR_ARRAY = new Class[0];
		private static final Attribute[] EMPTY_ATTRIBUTE_ARRAY = {};

		@Override
		public String name() {
			return "";
		}

		@Override
		public int pathIndex() {
			return -1;
		}

		@Override
		public String label() {
			return "";
		}

		@Override
		public String converter() {
			return "";
		}

		@Override
		public boolean required() {
			return false;
		}

		@Override
		public String[] validators() {
			return EMPTY_STRING_ARRAY;
		}

		@Override
		public Class<? extends Converter> converterClass() {
			return Converter.class;
		}

		@Override
		public Class<? extends Validator>[] validatorClasses() {
			return EMPTY_VALIDATOR_ARRAY;
		}

		@Override
		public Attribute[] converterAttributes() {
			return EMPTY_ATTRIBUTE_ARRAY;
		}

		@Override
		public Attribute[] validatorAttributes() {
			return EMPTY_ATTRIBUTE_ARRAY;
		}

		@Override
		public String converterMessage() {
			return "";
		}

		@Override
		public String validatorMessage() {
			return "";
		}

		@Override
		public String requiredMessage() {
			return "";
		}

		@Override
		public boolean disableBeanValidation() {
			return false;
		}

		@Override
		public boolean overrideGlobalBeanValidationDisabled() {
			return false;
		}
	}
}