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.Collections;
020import java.util.List;
021
022import javax.xml.bind.annotation.XmlAccessType;
023import javax.xml.bind.annotation.XmlAccessorType;
024import javax.xml.bind.annotation.XmlElementRef;
025import javax.xml.bind.annotation.XmlTransient;
026
027import org.apache.camel.Expression;
028import org.apache.camel.ExpressionFactory;
029import org.apache.camel.Predicate;
030import org.apache.camel.builder.ExpressionClause;
031import org.apache.camel.model.language.ExpressionDefinition;
032
033/**
034 * A base {@link ExpressionNode} which does <b>not</b> support any outputs.
035 * <p/>
036 * This node is to be extended by definitions which need to support an
037 * expression but the definition should not contain any outputs, such as
038 * {@link org.apache.camel.model.TransformDefinition}.
039 */
040@XmlAccessorType(XmlAccessType.FIELD)
041@XmlTransient
042public abstract class ExpressionNode extends ProcessorDefinition<ExpressionNode> {
043
044    @XmlElementRef
045    private ExpressionDefinition expression;
046
047    public ExpressionNode() {
048    }
049
050    public ExpressionNode(ExpressionDefinition expression) {
051        this.expression = expression;
052    }
053
054    public ExpressionNode(Expression expression) {
055        if (expression != null) {
056            setExpression(ExpressionNodeHelper.toExpressionDefinition(expression));
057        }
058    }
059
060    public ExpressionNode(Predicate predicate) {
061        if (predicate != null) {
062            setExpression(ExpressionNodeHelper.toExpressionDefinition(predicate));
063        }
064    }
065
066    public ExpressionDefinition getExpression() {
067        return expression;
068    }
069
070    public void setExpression(Expression expression) {
071        setExpression(new ExpressionDefinition(expression));
072    }
073
074    public void setExpression(ExpressionDefinition expression) {
075        // favour using the helper to set the expression as it can unwrap some
076        // unwanted builders when using Java DSL
077        this.expression = expression;
078    }
079
080    @Override
081    public String getLabel() {
082        if (getExpression() == null) {
083            return "";
084        }
085        return getExpression().getLabel();
086    }
087
088    @Override
089    public void configureChild(ProcessorDefinition<?> output) {
090        // reuse the logic from pre create processor
091        preCreateProcessor();
092    }
093
094    @Override
095    public void preCreateProcessor() {
096        Expression exp = getExpression();
097        if (getExpression() != null && getExpression().getExpressionValue() != null) {
098            exp = getExpression().getExpressionValue();
099        }
100
101        if (exp instanceof ExpressionClause) {
102            ExpressionClause<?> clause = (ExpressionClause<?>)exp;
103            if (clause.getExpressionType() != null) {
104                // if using the Java DSL then the expression may have been set
105                // using the
106                // ExpressionClause which is a fancy builder to define
107                // expressions and predicates
108                // using fluent builders in the DSL. However we need afterwards
109                // a callback to
110                // reset the expression to the expression type the
111                // ExpressionClause did build for us
112                ExpressionFactory model = clause.getExpressionType();
113                if (model instanceof ExpressionDefinition) {
114                    setExpression((ExpressionDefinition)model);
115                }
116            }
117        }
118
119        if (getExpression() != null && getExpression().getExpression() == null) {
120            // use toString from predicate or expression so we have some
121            // information to show in the route model
122            if (getExpression().getPredicate() != null) {
123                getExpression().setExpression(getExpression().getPredicate().toString());
124            } else if (getExpression().getExpressionValue() != null) {
125                getExpression().setExpression(getExpression().getExpressionValue().toString());
126            }
127        }
128    }
129
130    @Override
131    public List<ProcessorDefinition<?>> getOutputs() {
132        return Collections.emptyList();
133    }
134
135    @Override
136    public ExpressionNode id(String id) {
137        if (!(this instanceof OutputNode)) {
138            // let parent handle assigning the id, as we do not support outputs
139            getParent().id(id);
140            return this;
141        } else {
142            return super.id(id);
143        }
144    }
145
146}