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: AVTPart.java 468643 2006-10-28 06:56:03Z minchau $
20 */
21package org.apache.xalan.templates;
22
23import org.apache.xml.utils.FastStringBuffer;
24import org.apache.xpath.XPathContext;
25
26/**
27 * Class to hold a part, either a string or XPath,
28 * of an Attribute Value Template.
29 * @xsl.usage internal
30 */
31public abstract class AVTPart implements java.io.Serializable, XSLTVisitable
32{
33    static final long serialVersionUID = -1747749903613916025L;
34
35  /**
36   * Construct a part.
37   */
38  public AVTPart(){}
39
40  /**
41   * Get the AVT part as the original string.
42   *
43   * @return the AVT part as the original string.
44   */
45  public abstract String getSimpleString();
46
47  /**
48   * Write the evaluated value into the given
49   * string buffer.
50   *
51   * @param xctxt The XPath context to use to evaluate this AVT.
52   * @param buf Buffer to write into.
53   * @param context The current source tree context.
54   * @param nsNode The current namespace context (stylesheet tree context).
55   *
56   * @throws javax.xml.transform.TransformerException
57   */
58  public abstract void evaluate(
59    XPathContext xctxt, FastStringBuffer buf, int context,
60      org.apache.xml.utils.PrefixResolver nsNode)
61        throws javax.xml.transform.TransformerException;
62
63  /**
64   * Set the XPath support.
65   *
66   * @param support XPathContext to set.
67   */
68  public void setXPathSupport(XPathContext support){}
69
70  /**
71   * Tell if this expression or it's subexpressions can traverse outside
72   * the current subtree.
73   *
74   * @return true if traversal outside the context node's subtree can occur.
75   */
76   public boolean canTraverseOutsideSubtree()
77   {
78    return false;
79   }
80
81  /**
82   * This function is used to fixup variables from QNames to stack frame
83   * indexes at stylesheet build time.
84   * @param vars List of QNames that correspond to variables.  This list
85   * should be searched backwards for the first qualified name that
86   * corresponds to the variable reference qname.  The position of the
87   * QName in the vector from the start of the vector will be its position
88   * in the stack frame (but variables above the globalsTop value will need
89   * to be offset to the current stack frame).
90   */
91  public abstract void fixupVariables(java.util.Vector vars, int globalsSize);
92
93
94}
95