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