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Java example source code file (XslAttribute.java)

This example Java source code file (XslAttribute.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

attributevaluetemplate, avt, choose, elemdesc, indentincrement, instructionlist, literalelement, push, string, string_sig, syntaxtreenode, text, util, vector, xslattribute

The XslAttribute.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed 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: XslAttribute.java,v 1.2.4.1 2005/09/12 11:39:32 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ASTORE;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GETFIELD;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

import com.sun.org.apache.xml.internal.serializer.ElemDesc;
import com.sun.org.apache.xml.internal.serializer.SerializationHandler;
import com.sun.org.apache.xml.internal.utils.XML11Char;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 * @author Erwin Bolwidt <ejb@klomp.org>
 * @author Gunnlaugur Briem <gthb@dimon.is>
 */
final class XslAttribute extends Instruction {

    private String _prefix;
    private AttributeValue _name;       // name treated as AVT (7.1.3)
    private AttributeValueTemplate _namespace = null;
    private boolean _ignore = false;
    private boolean _isLiteral = false;  // specified name is not AVT

    /**
     * Returns the name of the attribute
     */
    public AttributeValue getName() {
        return _name;
    }

    /**
     * Displays the contents of the attribute
     */
    public void display(int indent) {
        indent(indent);
        Util.println("Attribute " + _name);
        displayContents(indent + IndentIncrement);
    }

    /**
     * Parses the attribute's contents. Special care taken for namespaces.
     */
    public void parseContents(Parser parser) {
        boolean generated = false;
        final SymbolTable stable = parser.getSymbolTable();

        String name = getAttribute("name");
        String namespace = getAttribute("namespace");
        QName qname = parser.getQName(name, false);
        final String prefix = qname.getPrefix();

        if (((prefix != null) && (prefix.equals(XMLNS_PREFIX)))||(name.equals(XMLNS_PREFIX))) {
            reportError(this, parser, ErrorMsg.ILLEGAL_ATTR_NAME_ERR, name);
            return;
        }

        _isLiteral = Util.isLiteral(name);
        if (_isLiteral) {
            if (!XML11Char.isXML11ValidQName(name)) {
                reportError(this, parser, ErrorMsg.ILLEGAL_ATTR_NAME_ERR, name);
                return;
            }
        }

        // Ignore attribute if preceeded by some other type of element
        final SyntaxTreeNode parent = getParent();
        final Vector siblings = parent.getContents();
        for (int i = 0; i < parent.elementCount(); i++) {
            SyntaxTreeNode item = (SyntaxTreeNode)siblings.elementAt(i);
            if (item == this) break;

            // These three objects result in one or more attribute output
            if (item instanceof XslAttribute) continue;
            if (item instanceof UseAttributeSets) continue;
            if (item instanceof LiteralAttribute) continue;
            if (item instanceof Text) continue;

            // These objects _can_ result in one or more attribute
            // The output handler will generate an error if not (at runtime)
            if (item instanceof If) continue;
            if (item instanceof Choose) continue;
            if (item instanceof CopyOf) continue;
            if (item instanceof VariableBase) continue;

            // Report warning but do not ignore attribute
            reportWarning(this, parser, ErrorMsg.STRAY_ATTRIBUTE_ERR, name);
        }

        // Get namespace from namespace attribute?
        if (namespace != null && namespace != Constants.EMPTYSTRING) {
            _prefix = lookupPrefix(namespace);
            _namespace = new AttributeValueTemplate(namespace, parser, this);
        }
        // Get namespace from prefix in name attribute?
        else if (prefix != null && prefix != Constants.EMPTYSTRING) {
            _prefix = prefix;
            namespace = lookupNamespace(prefix);
            if (namespace != null) {
                _namespace = new AttributeValueTemplate(namespace, parser, this);
            }
        }

        // Common handling for namespaces:
        if (_namespace != null) {
            // Generate prefix if we have none
            if (_prefix == null || _prefix == Constants.EMPTYSTRING) {
                if (prefix != null) {
                    _prefix = prefix;
                }
                else {
                    _prefix = stable.generateNamespacePrefix();
                    generated = true;
                }
            }
            else if (prefix != null && !prefix.equals(_prefix)) {
                _prefix = prefix;
            }

            name = _prefix + ":" + qname.getLocalPart();

            /*
             * TODO: The namespace URI must be passed to the parent
             * element but we don't yet know what the actual URI is
             * (as we only know it as an attribute value template).
             */
            if ((parent instanceof LiteralElement) && (!generated)) {
                ((LiteralElement)parent).registerNamespace(_prefix,
                                                           namespace,
                                                           stable, false);
            }
        }

        if (parent instanceof LiteralElement) {
            ((LiteralElement)parent).addAttribute(this);
        }

        _name = AttributeValue.create(this, name, parser);
        parseChildren(parser);
    }

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
        if (!_ignore) {
            _name.typeCheck(stable);
            if (_namespace != null) {
                _namespace.typeCheck(stable);
            }
            typeCheckContents(stable);
        }
        return Type.Void;
    }

    /**
     *
     */
    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
        final ConstantPoolGen cpg = classGen.getConstantPool();
        final InstructionList il = methodGen.getInstructionList();

        if (_ignore) return;
        _ignore = true;

        // Compile code that emits any needed namespace declaration
        if (_namespace != null) {
            // public void attribute(final String name, final String value)
            il.append(methodGen.loadHandler());
            il.append(new PUSH(cpg,_prefix));
            _namespace.translate(classGen,methodGen);
            il.append(methodGen.namespace());
        }

        if (!_isLiteral) {
            // if the qname is an AVT, then the qname has to be checked at runtime if it is a valid qname
            LocalVariableGen nameValue =
                    methodGen.addLocalVariable2("nameValue",
                    Util.getJCRefType(STRING_SIG),
                                                null);

            // store the name into a variable first so _name.translate only needs to be called once
            _name.translate(classGen, methodGen);
            nameValue.setStart(il.append(new ASTORE(nameValue.getIndex())));
            il.append(new ALOAD(nameValue.getIndex()));

            // call checkQName if the name is an AVT
            final int check = cpg.addMethodref(BASIS_LIBRARY_CLASS, "checkAttribQName",
                            "("
                            +STRING_SIG
                            +")V");
            il.append(new INVOKESTATIC(check));

            // Save the current handler base on the stack
            il.append(methodGen.loadHandler());
            il.append(DUP);     // first arg to "attributes" call

            // load name value again
            nameValue.setEnd(il.append(new ALOAD(nameValue.getIndex())));
        } else {
            // Save the current handler base on the stack
            il.append(methodGen.loadHandler());
            il.append(DUP);     // first arg to "attributes" call

            // Push attribute name
            _name.translate(classGen, methodGen);// 2nd arg

        }

        // Push attribute value - shortcut for literal strings
        if ((elementCount() == 1) && (elementAt(0) instanceof Text)) {
            il.append(new PUSH(cpg, ((Text)elementAt(0)).getText()));
        }
        else {
            il.append(classGen.loadTranslet());
            il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
                                                   "stringValueHandler",
                                                   STRING_VALUE_HANDLER_SIG)));
            il.append(DUP);
            il.append(methodGen.storeHandler());
            // translate contents with substituted handler
            translateContents(classGen, methodGen);
            // get String out of the handler
            il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_VALUE_HANDLER,
                                                         "getValue",
                                                         "()" + STRING_SIG)));
        }

        SyntaxTreeNode parent = getParent();
        if (parent instanceof LiteralElement
            && ((LiteralElement)parent).allAttributesUnique()) {
            int flags = 0;
            ElemDesc elemDesc = ((LiteralElement)parent).getElemDesc();

            // Set the HTML flags
            if (elemDesc != null && _name instanceof SimpleAttributeValue) {
                String attrName = ((SimpleAttributeValue)_name).toString();
                if (elemDesc.isAttrFlagSet(attrName, ElemDesc.ATTREMPTY)) {
                    flags = flags | SerializationHandler.HTML_ATTREMPTY;
                }
                else if (elemDesc.isAttrFlagSet(attrName, ElemDesc.ATTRURL)) {
                    flags = flags | SerializationHandler.HTML_ATTRURL;
                }
            }
            il.append(new PUSH(cpg, flags));
            il.append(methodGen.uniqueAttribute());
        }
        else {
            // call "attribute"
            il.append(methodGen.attribute());
        }

        // Restore old handler base from stack
        il.append(methodGen.storeHandler());



    }

}

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