001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.model;
018
019import javax.xml.bind.annotation.XmlRootElement;
020
021import org.apache.camel.Predicate;
022import org.apache.camel.model.language.ExpressionDefinition;
023import org.apache.camel.spi.AsPredicate;
024import org.apache.camel.spi.Metadata;
025
026/**
027 * Triggers a route when an expression evaluates to <tt>true</tt>
028 */
029@Metadata(label = "eip,routing")
030@AsPredicate
031@XmlRootElement(name = "when")
032public class WhenDefinition extends OutputExpressionNode {
033
034    public WhenDefinition() {
035    }
036
037    public WhenDefinition(Predicate predicate) {
038        super(predicate);
039    }
040
041    public WhenDefinition(ExpressionDefinition expression) {
042        super(expression);
043    }
044
045    @Override
046    public String toString() {
047        return "When[" + description() + " -> " + getOutputs() + "]";
048    }
049
050    protected String description() {
051        StringBuilder sb = new StringBuilder();
052        if (getExpression() != null) {
053            String language = getExpression().getLanguage();
054            if (language != null) {
055                sb.append(language).append("{");
056            }
057            sb.append(getExpression().getLabel());
058            if (language != null) {
059                sb.append("}");
060            }
061        }
062        return sb.toString();
063    }
064
065    @Override
066    public String getShortName() {
067        return "when";
068    }
069
070    @Override
071    public String getLabel() {
072        return "when[" + description() + "]";
073    }
074
075    /**
076     * Expression used as the predicate to evaluate whether this when should
077     * trigger and route the message or not.
078     */
079    @Override
080    public void setExpression(ExpressionDefinition expression) {
081        // override to include javadoc what the expression is used for
082        super.setExpression(expression);
083    }
084
085    @Override
086    public ProcessorDefinition<?> endParent() {
087        // when using when in the DSL we don't want to end back to this when,
088        // but instead
089        // the parent of this, so return the parent
090        return this.getParent();
091    }
092}