/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.olingo.server.api.uri.queryoption.apply;

import java.util.List;

import org.apache.olingo.server.api.uri.UriResource;

/**
 * Represents a grouping property.
 * @see GroupBy
 */
public interface GroupByItem {

  /**
   * Gets the path.
   * @return a (potentially empty) list of path segments (and never <code>null</code>)
   */
  List<UriResource> getPath();

  /**
   * Whether a nested rollup clause contains the special value '$all'.
   * @return <code>true</code> if '$all' has been given in rollup, <code>false</code> otherwise
   */
  boolean isRollupAll();

  /**
   * Gets the rollup.
   * @return a (potentially empty) list of grouping items (and never <code>null</code>)
   */
  List<GroupByItem> getRollup();
}
