01: /*
02: * Copyright 1999-2004 The Apache Software Foundation.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16: /*
17: * $Id: AVTPart.java,v 1.17 2005/01/23 00:27:29 mcnamara Exp $
18: */
19: package org.apache.xalan.templates;
20:
21: import org.apache.xml.utils.FastStringBuffer;
22: import org.apache.xpath.XPathContext;
23:
24: /**
25: * Class to hold a part, either a string or XPath,
26: * of an Attribute Value Template.
27: * @xsl.usage internal
28: */
29: public abstract class AVTPart implements java.io.Serializable,
30: XSLTVisitable {
31: static final long serialVersionUID = -1747749903613916025L;
32:
33: /**
34: * Construct a part.
35: */
36: public AVTPart() {
37: }
38:
39: /**
40: * Get the AVT part as the original string.
41: *
42: * @return the AVT part as the original string.
43: */
44: public abstract String getSimpleString();
45:
46: /**
47: * Write the evaluated value into the given
48: * string buffer.
49: *
50: * @param xctxt The XPath context to use to evaluate this AVT.
51: * @param buf Buffer to write into.
52: * @param context The current source tree context.
53: * @param nsNode The current namespace context (stylesheet tree context).
54: *
55: * @throws javax.xml.transform.TransformerException
56: */
57: public abstract void evaluate(XPathContext xctxt,
58: FastStringBuffer buf, int context,
59: org.apache.xml.utils.PrefixResolver nsNode)
60: throws javax.xml.transform.TransformerException;
61:
62: /**
63: * Set the XPath support.
64: *
65: * @param support XPathContext to set.
66: */
67: public void setXPathSupport(XPathContext support) {
68: }
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: return false;
78: }
79:
80: /**
81: * This function is used to fixup variables from QNames to stack frame
82: * indexes at stylesheet build time.
83: * @param vars List of QNames that correspond to variables. This list
84: * should be searched backwards for the first qualified name that
85: * corresponds to the variable reference qname. The position of the
86: * QName in the vector from the start of the vector will be its position
87: * in the stack frame (but variables above the globalsTop value will need
88: * to be offset to the current stack frame).
89: */
90: public abstract void fixupVariables(java.util.Vector vars,
91: int globalsSize);
92:
93: }
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