code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import java.util.Enumeration;
  import java.util.Vector;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.INVOKESPECIAL;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.xalan.xsltc.compiler.util.AttributeSetMethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  import org.apache.xalan.xsltc.compiler.util.Util;
  import org.apache.xml.utils.XML11Char;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  final class AttributeSet extends TopLevelElement {
  
      // This prefix is used for the method name of attribute set methods
      private static final String AttributeSetPrefix = "$as$";
      
      // Element contents
      private QName            _name;
      private UseAttributeSets _useSets;
      private AttributeSet     _mergeSet;
      private String           _method;
      private boolean          _ignore = false;
      
      /**
       * Returns the QName of this attribute set
       */
      public QName getName() {
  	return _name;
      }
  
      /**
       * Returns the method name of this attribute set. This method name is
       * generated by the compiler (XSLTC)
       */
      public String getMethodName() {
  	return _method;
      }
  
      /**
       * Call this method to prevent a method for being compiled for this set.
       * This is used in case several <xsl:attribute-set...> elements constitute
       * a single set (with one name). The last element will merge itself with
       * any previous set(s) with the same name and disable the other set(s).
       */
      public void ignore() {
  	_ignore = true;
      }
  
      /**
       * Parse the contents of this attribute set. Recognised attributes are
       * "name" (required) and "use-attribute-sets" (optional).
       */
      public void parseContents(Parser parser) {
  	
  	// Get this attribute set's name
          final String name = getAttribute("name");
          
          if (!XML11Char.isXML11ValidQName(name)) {
              ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);
              parser.reportError(Constants.ERROR, err);           
          }        
          _name = parser.getQNameIgnoreDefaultNs(name);
  	if ((_name == null) || (_name.equals(EMPTYSTRING))) {
  	    ErrorMsg msg = new ErrorMsg(ErrorMsg.UNNAMED_ATTRIBSET_ERR, this);
  	    parser.reportError(Constants.ERROR, msg);
  	}
  
  	// Get any included attribute sets (similar to inheritance...)
  	final String useSets = getAttribute("use-attribute-sets");
  	if (useSets.length() > 0) {
              if (!Util.isValidQNames(useSets)) {
                  ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, useSets, this);
                  parser.reportError(Constants.ERROR, err);	
              }		
  	    _useSets = new UseAttributeSets(useSets, parser);
  	}
  
  	// Parse the contents of this node. All child elements must be
  	// <xsl:attribute> elements. Other elements cause an error.
  	final Vector contents = getContents();
  	final int count = contents.size();
  	for (int i=0; i<count; i++) {
  	    SyntaxTreeNode child = (SyntaxTreeNode)contents.elementAt(i);
  	    if (child instanceof XslAttribute) {
  		parser.getSymbolTable().setCurrentNode(child);
  		child.parseContents(parser);
  	    }
  	    else if (child instanceof Text) {
  		// ignore
  	    }
  	    else {
  		ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_CHILD_ERR, this);
  		parser.reportError(Constants.ERROR, msg);
  	    }
  	}
  
  	// Point the symbol table back at us...
  	parser.getSymbolTable().setCurrentNode(this);
      }
  
      /**
       * Type check the contents of this element
       */
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  
  	if (_ignore) return (Type.Void);
  
          // _mergeSet Point to any previous definition of this attribute set
  	_mergeSet = stable.addAttributeSet(this);
  
  	_method = AttributeSetPrefix + getXSLTC().nextAttributeSetSerial();
  
  	if (_useSets != null) _useSets.typeCheck(stable);
  	typeCheckContents(stable);
  	return Type.Void;
      }
  
      /**
       * Compile a method that outputs the attributes in this set
       */
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  
  	if (_ignore) return;
  
  	// Create a new method generator for an attribute set method
  	methodGen = new AttributeSetMethodGenerator(_method, classGen);
  
          // Generate a reference to previous attribute-set definitions with the
          // same name first.  Those later in the stylesheet take precedence.
          if (_mergeSet != null) {
              final ConstantPoolGen cpg = classGen.getConstantPool();
              final InstructionList il = methodGen.getInstructionList();
              final String methodName = _mergeSet.getMethodName();
  
              il.append(classGen.loadTranslet());
              il.append(methodGen.loadDOM());
              il.append(methodGen.loadIterator());
              il.append(methodGen.loadHandler());
              final int method = cpg.addMethodref(classGen.getClassName(),
                                                  methodName, ATTR_SET_SIG);
              il.append(new INVOKESPECIAL(method));
          }
  
  	// Translate other used attribute sets first, as local attributes
  	// take precedence (last attributes overrides first)
  	if (_useSets != null) _useSets.translate(classGen, methodGen);
  
  	// Translate all local attributes
  	final Enumeration attributes = elements();
  	while (attributes.hasMoreElements()) {
  	    SyntaxTreeNode element = (SyntaxTreeNode)attributes.nextElement();
  	    if (element instanceof XslAttribute) {
  		final XslAttribute attribute = (XslAttribute)element;
  		attribute.translate(classGen, methodGen);
  	    }
  	}
  	final InstructionList il = methodGen.getInstructionList();
  	il.append(RETURN);
  	
  	classGen.addMethod(methodGen);
      }
  
      public String toString() {
  	StringBuffer buf = new StringBuffer("attribute-set: ");
  	// Translate all local attributes
  	final Enumeration attributes = elements();
  	while (attributes.hasMoreElements()) {
  	    final XslAttribute attribute =
  		(XslAttribute)attributes.nextElement();
  	    buf.append(attribute);
  	}
  	return(buf.toString());
      }
  }
  