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.processor.FilterProcessor;
024import org.apache.camel.spi.AsPredicate;
025import org.apache.camel.spi.Metadata;
026import org.apache.camel.spi.RouteContext;
027
028/**
029 * Triggers a route when an expression evaluates to <tt>true</tt>
030 * 
031 * @version 
032 */
033@Metadata(label = "eip,routing") @AsPredicate
034@XmlRootElement(name = "when")
035public class WhenDefinition extends ExpressionNode {
036
037    public WhenDefinition() {
038    }
039
040    public WhenDefinition(Predicate predicate) {
041        super(predicate);
042    }
043
044    public WhenDefinition(ExpressionDefinition expression) {
045        super(expression);
046    }
047
048    @Override
049    public String toString() {
050        return "When[" + description() + " -> " + getOutputs() + "]";
051    }
052
053    protected String description() {
054        StringBuilder sb = new StringBuilder();
055        if (getExpression() != null) {
056            String language = getExpression().getLanguage();
057            if (language != null) {
058                sb.append(language).append("{");
059            }
060            sb.append(getExpression().getLabel());
061            if (language != null) {
062                sb.append("}");
063            }
064        }
065        return sb.toString();
066    }
067
068    @Override
069    public String getShortName() {
070        return "when";
071    }
072
073    @Override
074    public String getLabel() {
075        return "when[" + description() + "]";
076    }
077
078    @Override
079    public FilterProcessor createProcessor(RouteContext routeContext) throws Exception {
080        return createFilterProcessor(routeContext);
081    }
082
083    /**
084     * Expression used as the predicate to evaluate whether this when should trigger and route the message or not.
085     */
086    @Override
087    public void setExpression(ExpressionDefinition expression) {
088        // override to include javadoc what the expression is used for
089        super.setExpression(expression);
090    }
091
092    @Override
093    public ProcessorDefinition<?> endParent() {
094        // when using when in the DSL we don't want to end back to this when, but instead
095        // the parent of this, so return the parent
096        return this.getParent();
097    }
098}