/*
* Copyright 2013-2017 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.aggregation;
import org.bson.Document;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.data.domain.Sort.Order;
import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
import org.springframework.util.Assert;
/**
* Encapsulates the aggregation framework {@code $sort}-operation.
* <p>
* We recommend to use the static factory method {@link Aggregation#sort(Direction, String...)} instead of creating
* instances of this class directly.
*
* @author Thomas Darimont
* @author Oliver Gierke
* @author Christoph Strobl
* @author Mark Paluch
* @since 1.3
* @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/sort/">MongoDB Aggregation Framework: $sort</a>
*/
public class SortOperation implements AggregationOperation {
private final Sort sort;
/**
* Creates a new {@link SortOperation} for the given {@link Sort} instance.
*
* @param sort must not be {@literal null}.
*/
public SortOperation(Sort sort) {
Assert.notNull(sort, "Sort must not be null!");
this.sort = sort;
}
public SortOperation and(Direction direction, String... fields) {
return and(Sort.by(direction, fields));
}
public SortOperation and(Sort sort) {
return new SortOperation(this.sort.and(sort));
}
/*
* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.AggregationOperation#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
*/
@Override
public Document toDocument(AggregationOperationContext context) {
Document object = new Document();
for (Order order : sort) {
// Check reference
FieldReference reference = context.getReference(order.getProperty());
object.put(reference.getRaw(), order.isAscending() ? 1 : -1);
}
return new Document("$sort", object);
}
}