1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the  "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 /*
19  * $Id: VarNameCollector.java 468643 2006-10-28 06:56:03Z minchau $
20  */
21 package org.apache.xalan.templates;
22 
23 import java.util.Vector;
24 
25 import org.apache.xml.utils.QName;
26 import org.apache.xpath.ExpressionOwner;
27 import org.apache.xpath.XPathVisitor;
28 import org.apache.xpath.operations.Variable;
29 
30 /**
31  * This class visits variable refs in an XPath and collects their QNames.
32  */
33 public class VarNameCollector extends XPathVisitor
34 {
35 	Vector m_refs = new Vector();
36 
37 	/**
38 	 * Reset the list for a fresh visitation and collection.
39 	 */
reset()40 	public void reset()
41 	{
42 		m_refs.removeAllElements(); //.clear();
43 	}
44 
45 	/**
46 	 * Get the number of variable references that were collected.
47 	 * @return the size of the list.
48 	 */
getVarCount()49 	public int getVarCount()
50 	{
51 		return m_refs.size();
52 	}
53 
54 	/**
55 	 * Tell if the given qualified name occurs in
56 	 * the list of qualified names collected.
57 	 *
58 	 * @param refName Must be a valid qualified name.
59 	 * @return true if the list contains the qualified name.
60 	 */
doesOccur(QName refName)61 	boolean doesOccur(QName refName)
62 	{
63 		return m_refs.contains(refName);
64 	}
65 
66 	/**
67 	 * Visit a variable reference.
68 	 * @param owner The owner of the expression, to which the expression can
69 	 *              be reset if rewriting takes place.
70 	 * @param var The variable reference object.
71 	 * @return true if the sub expressions should be traversed.
72 	 */
visitVariableRef(ExpressionOwner owner, Variable var)73 	public boolean visitVariableRef(ExpressionOwner owner, Variable var)
74 	{
75 		m_refs.addElement(var.getQName());
76 		return true;
77 	}
78 
79 }
80 
81