/*
* Copyright 2010 Alibaba Group Holding Limited.
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.citrus.service.velocity.impl;
import java.io.Reader;
import org.apache.velocity.runtime.RuntimeInstance;
import org.apache.velocity.runtime.parser.ParseException;
import org.apache.velocity.runtime.parser.node.ASTStringLiteral;
import org.apache.velocity.runtime.parser.node.Node;
import org.apache.velocity.runtime.parser.node.SimpleNode;
import com.alibaba.citrus.service.velocity.impl.parser.ASTStringLiteralEnhanced;
import com.alibaba.citrus.service.velocity.impl.parser.SimpleNodeUtil;
/**
* ��չ��velocity��<code>RuntimeInstance</code>�࣬ʵ��һ�����ܣ�ʹ
* <code>ReferenceInsertionEventHandler</code>���Ը�֪�����ص������Ƿ�λ��
* <code>StringLiteral</code>�С� ���磺
* <p>
* <code>EscapeSupport</code>���Ը������õ�λ�ã��������Ƿ�Ҫ�Խ������escapeת�塣�����velocity��佫���ᱻת�壺
* </p>
*
* <pre>
* #set ($value = "hello, $name")
* </pre>
* <p>
* ͨ������<code>InterpolationUtil.isInInterpolation(context)</code>����֪����ϸ�ڡ�
* </p>
* <p>
* ͨ��velocity configuration��
* <code>runtime.interpolate.string.literals.hack</code>���Կ��ش����ԣ�Ĭ��ֵΪ
* <code>true</code>��
* </p>
*
* @author Michael Zhou
*/
public class VelocityRuntimeInstance extends RuntimeInstance {
private static final String INTERPOLATION_HACK_KEY = "runtime.interpolate.string.literals.hack";
private static final Boolean INTERPOLATION_HACK_DEFAULT = true;
private boolean interpolationHack;
@Override
public synchronized void init() throws Exception {
super.init();
interpolationHack = getConfiguration().getBoolean(INTERPOLATION_HACK_KEY, INTERPOLATION_HACK_DEFAULT);
}
@Override
public SimpleNode parse(Reader reader, String templateName, boolean dumpNamespace) throws ParseException {
SimpleNode node = super.parse(reader, templateName, dumpNamespace);
if (interpolationHack) {
node = traversNode(node);
}
return node;
}
private SimpleNode traversNode(SimpleNode node) {
int length = node.jjtGetNumChildren();
for (int i = 0; i < length; i++) {
Node child = node.jjtGetChild(i);
if (child instanceof ASTStringLiteral) {
replaceStringLiteral(node, (ASTStringLiteral) child, i);
}
if (child instanceof SimpleNode) {
traversNode((SimpleNode) child);
}
}
return node;
}
private void replaceStringLiteral(SimpleNode parent, ASTStringLiteral strLit, int index) {
if (!(strLit instanceof ASTStringLiteralEnhanced)) {
SimpleNodeUtil.jjtSetChild(parent, new ASTStringLiteralEnhanced(strLit), index);
}
}
}