001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.svl.vars;
014
015import org.apache.juneau.svl.*;
016
017/**
018 * A basic variable resolver that returns the first non-null value.
019 * 
020 * <p>
021 * The format for this var is <js>"$CO{arg1[,arg2...]}"</js>.
022 * 
023 * 
024 * <h5 class='section'>See Also:</h5>
025 * <ul>
026 *    <li class='link'><a class="doclink" href="../../../../../overview-summary.html#juneau-svl.SvlVariables">Overview &gt; juneau-svl &gt; SVL Variables</a>
027 * </ul>
028 */
029public class CoalesceVar extends MultipartResolvingVar {
030
031   /** The name of this variable. */
032   public static final String NAME = "CO";
033
034   /**
035    * Constructor.
036    */
037   public CoalesceVar() {
038      super(NAME);
039   }
040
041   @Override
042   public String resolve(VarResolverSession session, String arg) throws Exception {
043      return arg;
044   }
045}