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}