/*
* Copyright 2013-2016 the original author or authors.
*
* 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.springframework.data.mongodb.core.convert;
import org.bson.Document;
import java.util.List;
import java.util.Optional;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
import com.mongodb.DBRef;
/**
* Used to resolve associations annotated with {@link org.springframework.data.mongodb.core.mapping.DBRef}.
*
* @author Thomas Darimont
* @author Oliver Gierke
* @author Christoph Strobl
* @author Mark Paluch
* @since 1.4
*/
public interface DbRefResolver {
/**
* Resolves the given {@link DBRef} into an object of the given {@link MongoPersistentProperty}'s type. The method
* might return a proxy object for the {@link DBRef} or resolve it immediately. In both cases the
* {@link DbRefResolverCallback} will be used to obtain the actual backing object.
*
* @param property will never be {@literal null}.
* @param dbref the {@link DBRef} to resolve.
* @param callback will never be {@literal null}.
* @return
*/
Optional<Object> resolveDbRef(MongoPersistentProperty property, DBRef dbref, DbRefResolverCallback callback,
DbRefProxyHandler proxyHandler);
/**
* Creates a {@link DBRef} instance for the given {@link org.springframework.data.mongodb.core.mapping.DBRef}
* annotation, {@link MongoPersistentEntity} and id.
*
* @param annotation will never be {@literal null}.
* @param entity will never be {@literal null}.
* @param id will never be {@literal null}.
* @return
*/
DBRef createDbRef(org.springframework.data.mongodb.core.mapping.DBRef annotation, MongoPersistentEntity<?> entity,
Object id);
/**
* Actually loads the {@link DBRef} from the datasource.
*
* @param dbRef must not be {@literal null}.
* @return
* @since 1.7
*/
Document fetch(DBRef dbRef);
/**
* Loads a given {@link List} of {@link DBRef}s from the datasource in one batch. The resulting {@link List} of
* {@link Document} will reflect the ordering of the {@link DBRef} passed in.<br />
* The {@link DBRef} elements in the list must not reference different collections.
*
* @param dbRefs must not be {@literal null}.
* @return never {@literal null}.
* @throws InvalidDataAccessApiUsageException in case not all {@link DBRef} target the same collection.
* @since 1.10
*/
List<Document> bulkFetch(List<DBRef> dbRefs);
}