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 */
017 package org.apache.camel.model;
018
019 import java.util.ArrayList;
020 import java.util.List;
021 import javax.xml.bind.annotation.XmlAccessType;
022 import javax.xml.bind.annotation.XmlAccessorType;
023 import javax.xml.bind.annotation.XmlElementRef;
024
025 import org.apache.camel.Expression;
026 import org.apache.camel.Predicate;
027 import org.apache.camel.Processor;
028 import org.apache.camel.builder.ExpressionClause;
029 import org.apache.camel.model.language.ExpressionDefinition;
030 import org.apache.camel.processor.FilterProcessor;
031 import org.apache.camel.spi.Required;
032 import org.apache.camel.spi.RouteContext;
033
034 /**
035 * A base class for nodes which contain an expression and a number of outputs
036 *
037 * @version
038 */
039 @XmlAccessorType(XmlAccessType.FIELD)
040 public class ExpressionNode extends ProcessorDefinition<ExpressionNode> {
041 @XmlElementRef
042 private ExpressionDefinition expression;
043 @XmlElementRef
044 private List<ProcessorDefinition<?>> outputs = new ArrayList<ProcessorDefinition<?>>();
045
046 public ExpressionNode() {
047 }
048
049 public ExpressionNode(ExpressionDefinition expression) {
050 this.expression = expression;
051 }
052
053 public ExpressionNode(Expression expression) {
054 if (expression != null) {
055 setExpression(ExpressionNodeHelper.toExpressionDefinition(expression));
056 }
057 }
058
059 public ExpressionNode(Predicate predicate) {
060 if (predicate != null) {
061 setExpression(ExpressionNodeHelper.toExpressionDefinition(predicate));
062 }
063 }
064
065 @Override
066 public String getShortName() {
067 return "exp";
068 }
069
070 public ExpressionDefinition getExpression() {
071 return expression;
072 }
073
074 @Required
075 public void setExpression(ExpressionDefinition expression) {
076 this.expression = expression;
077 }
078
079 @Override
080 public List<ProcessorDefinition<?>> getOutputs() {
081 return outputs;
082 }
083
084 public void setOutputs(List<ProcessorDefinition<?>> outputs) {
085 this.outputs = outputs;
086 }
087
088 @Override
089 public boolean isOutputSupported() {
090 return true;
091 }
092
093 @Override
094 public String getLabel() {
095 if (getExpression() == null) {
096 return "";
097 }
098 return getExpression().getLabel();
099 }
100
101 /**
102 * Creates the {@link FilterProcessor} from the expression node.
103 *
104 * @param routeContext the route context
105 * @return the created {@link FilterProcessor}
106 * @throws Exception is thrown if error creating the processor
107 */
108 protected FilterProcessor createFilterProcessor(RouteContext routeContext) throws Exception {
109 Processor childProcessor = createOutputsProcessor(routeContext);
110 return new FilterProcessor(createPredicate(routeContext), childProcessor);
111 }
112
113 /**
114 * Creates the {@link Predicate} from the expression node.
115 *
116 * @param routeContext the route context
117 * @return the created predicate
118 */
119 protected Predicate createPredicate(RouteContext routeContext) {
120 return getExpression().createPredicate(routeContext);
121 }
122
123 @Override
124 protected void configureChild(ProcessorDefinition<?> output) {
125 // reuse the logic from pre create processor
126 preCreateProcessor();
127 }
128
129 @Override
130 protected void preCreateProcessor() {
131 Expression exp = expression;
132 if (expression != null && expression.getExpressionValue() != null) {
133 exp = expression.getExpressionValue();
134 }
135
136 if (exp instanceof ExpressionClause) {
137 ExpressionClause<?> clause = (ExpressionClause<?>) exp;
138 if (clause.getExpressionType() != null) {
139 // if using the Java DSL then the expression may have been set using the
140 // ExpressionClause which is a fancy builder to define expressions and predicates
141 // using fluent builders in the DSL. However we need afterwards a callback to
142 // reset the expression to the expression type the ExpressionClause did build for us
143 expression = clause.getExpressionType();
144 }
145 }
146
147 if (expression != null && expression.getExpression() == null) {
148 // use toString from predicate or expression so we have some information to show in the route model
149 if (expression.getPredicate() != null) {
150 expression.setExpression(expression.getPredicate().toString());
151 } else if (expression.getExpressionValue() != null) {
152 expression.setExpression(expression.getExpressionValue().toString());
153 }
154 }
155 }
156 }