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1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   /*
6    * Copyright 2001-2004 The Apache Software Foundation.
7    *
8    * Licensed under the Apache License, Version 2.0 (the "License");
9    * you may not use this file except in compliance with the License.
10   * You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  /*
21   * $Id: AttributeSet.java,v 1.5 2005/09/28 13:48:04 pvedula Exp $
22   */
23  
24  package com.sun.org.apache.xalan.internal.xsltc.compiler;
25  
26  import java.util.Enumeration;
27  import java.util.Vector;
28  
29  import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
30  import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
31  import com.sun.org.apache.bcel.internal.generic.InstructionList;
32  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.AttributeSetMethodGenerator;
33  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
34  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
35  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
36  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
37  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
38  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
39  import com.sun.org.apache.xml.internal.utils.XML11Char;
40  
41  /**
42   * @author Jacek Ambroziak
43   * @author Santiago Pericas-Geertsen
44   * @author Morten Jorgensen
45   */
46  final class AttributeSet extends TopLevelElement {
47  
48      // This prefix is used for the method name of attribute set methods
49      private static final String AttributeSetPrefix = "$as$";
50  
51      // Element contents
52      private QName            _name;
53      private UseAttributeSets _useSets;
54      private AttributeSet     _mergeSet;
55      private String           _method;
56      private boolean          _ignore = false;
57  
58      /**
59       * Returns the QName of this attribute set
60       */
61      public QName getName() {
62          return _name;
63      }
64  
65      /**
66       * Returns the method name of this attribute set. This method name is
67       * generated by the compiler (XSLTC)
68       */
69      public String getMethodName() {
70          return _method;
71      }
72  
73      /**
74       * Call this method to prevent a method for being compiled for this set.
75       * This is used in case several <xsl:attribute-set...> elements constitute
76       * a single set (with one name). The last element will merge itself with
77       * any previous set(s) with the same name and disable the other set(s).
78       */
79      public void ignore() {
80          _ignore = true;
81      }
82  
83      /**
84       * Parse the contents of this attribute set. Recognised attributes are
85       * "name" (required) and "use-attribute-sets" (optional).
86       */
87      public void parseContents(Parser parser) {
88  
89          // Get this attribute set's name
90          final String name = getAttribute("name");
91  
92          if (!XML11Char.isXML11ValidQName(name)) {
93              ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);
94              parser.reportError(Constants.ERROR, err);
95          }
96          _name = parser.getQNameIgnoreDefaultNs(name);
97          if ((_name == null) || (_name.equals(EMPTYSTRING))) {
98              ErrorMsg msg = new ErrorMsg(ErrorMsg.UNNAMED_ATTRIBSET_ERR, this);
99              parser.reportError(Constants.ERROR, msg);
100         }
101 
102         // Get any included attribute sets (similar to inheritance...)
103         final String useSets = getAttribute("use-attribute-sets");
104         if (useSets.length() > 0) {
105             if (!Util.isValidQNames(useSets)) {
106                 ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, useSets, this);
107                 parser.reportError(Constants.ERROR, err);
108             }
109             _useSets = new UseAttributeSets(useSets, parser);
110         }
111 
112         // Parse the contents of this node. All child elements must be
113         // <xsl:attribute> elements. Other elements cause an error.
114         final Vector contents = getContents();
115         final int count = contents.size();
116         for (int i=0; i<count; i++) {
117             SyntaxTreeNode child = (SyntaxTreeNode)contents.elementAt(i);
118             if (child instanceof XslAttribute) {
119                 parser.getSymbolTable().setCurrentNode(child);
120                 child.parseContents(parser);
121             }
122             else if (child instanceof Text) {
123                 // ignore
124             }
125             else {
126                 ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_CHILD_ERR, this);
127                 parser.reportError(Constants.ERROR, msg);
128             }
129         }
130 
131         // Point the symbol table back at us...
132         parser.getSymbolTable().setCurrentNode(this);
133     }
134 
135     /**
136      * Type check the contents of this element
137      */
138     public Type typeCheck(SymbolTable stable) throws TypeCheckError {
139 
140         if (_ignore) return (Type.Void);
141 
142         // _mergeSet Point to any previous definition of this attribute set
143         _mergeSet = stable.addAttributeSet(this);
144 
145         _method = AttributeSetPrefix + getXSLTC().nextAttributeSetSerial();
146 
147         if (_useSets != null) _useSets.typeCheck(stable);
148         typeCheckContents(stable);
149         return Type.Void;
150     }
151 
152     /**
153      * Compile a method that outputs the attributes in this set
154      */
155     public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
156 
157         if (_ignore) return;
158 
159         // Create a new method generator for an attribute set method
160         methodGen = new AttributeSetMethodGenerator(_method, classGen);
161 
162         // Generate a reference to previous attribute-set definitions with the
163         // same name first.  Those later in the stylesheet take precedence.
164         if (_mergeSet != null) {
165             final ConstantPoolGen cpg = classGen.getConstantPool();
166             final InstructionList il = methodGen.getInstructionList();
167             final String methodName = _mergeSet.getMethodName();
168 
169             il.append(classGen.loadTranslet());
170             il.append(methodGen.loadDOM());
171             il.append(methodGen.loadIterator());
172             il.append(methodGen.loadHandler());
173             il.append(methodGen.loadCurrentNode());
174             final int method = cpg.addMethodref(classGen.getClassName(),
175                                                 methodName, ATTR_SET_SIG);
176             il.append(new INVOKESPECIAL(method));
177         }
178 
179         // Translate other used attribute sets first, as local attributes
180         // take precedence (last attributes overrides first)
181         if (_useSets != null) _useSets.translate(classGen, methodGen);
182 
183         // Translate all local attributes
184         final Enumeration attributes = elements();
185         while (attributes.hasMoreElements()) {
186             SyntaxTreeNode element = (SyntaxTreeNode)attributes.nextElement();
187             if (element instanceof XslAttribute) {
188                 final XslAttribute attribute = (XslAttribute)element;
189                 attribute.translate(classGen, methodGen);
190             }
191         }
192         final InstructionList il = methodGen.getInstructionList();
193         il.append(RETURN);
194 
195         classGen.addMethod(methodGen);
196     }
197 
198     public String toString() {
199         StringBuffer buf = new StringBuffer("attribute-set: ");
200         // Translate all local attributes
201         final Enumeration attributes = elements();
202         while (attributes.hasMoreElements()) {
203             final XslAttribute attribute =
204                 (XslAttribute)attributes.nextElement();
205             buf.append(attribute);
206         }
207         return(buf.toString());
208     }
209 }