alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (CallTemplate.java)

This example Java source code file (CallTemplate.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

calltemplate, errormsg, instructionlist, invokevirtual, node_iterator_sig, object, qname, string, stringbuffer, syntaxtreenode, template, typecheckerror, util, vector, withparam

The CallTemplate.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: CallTemplate.java,v 1.2.4.1 2005/09/12 10:02:41 pvedula Exp $
 */

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

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.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
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.utils.XML11Char;

import java.util.Vector;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Erwin Bolwidt <ejb@klomp.org>
 */
final class CallTemplate extends Instruction {

    /**
     * Name of template to call.
     */
    private QName _name;

    /**
     * The array of effective parameters in this CallTemplate. An object in
     * this array can be either a WithParam or a Param if no WithParam
     * exists for a particular parameter.
     */
    private Object[] _parameters = null;

    /**
     * The corresponding template which this CallTemplate calls.
     */
    private Template _calleeTemplate = null;

    public void display(int indent) {
        indent(indent);
        System.out.print("CallTemplate");
        Util.println(" name " + _name);
        displayContents(indent + IndentIncrement);
    }

    public boolean hasWithParams() {
        return elementCount() > 0;
    }

    public void parseContents(Parser parser) {
        final String name = getAttribute("name");
        if (name.length() > 0) {
            if (!XML11Char.isXML11ValidQName(name)) {
                ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);
                parser.reportError(Constants.ERROR, err);
            }
            _name = parser.getQNameIgnoreDefaultNs(name);
        }
        else {
            reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "name");
        }
        parseChildren(parser);
    }

    /**
     * Verify that a template with this name exists.
     */
    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
        final Template template = stable.lookupTemplate(_name);
        if (template != null) {
            typeCheckContents(stable);
        }
        else {
            ErrorMsg err = new ErrorMsg(ErrorMsg.TEMPLATE_UNDEF_ERR,_name,this);
            throw new TypeCheckError(err);
        }
        return Type.Void;
    }

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

        // If there are Params in the stylesheet or WithParams in this call?
        if (stylesheet.hasLocalParams() || hasContents()) {
            _calleeTemplate = getCalleeTemplate();

            // Build the parameter list if the called template is simple named
            if (_calleeTemplate != null) {
                buildParameterList();
            }
            // This is only needed when the called template is not
            // a simple named template.
            else {
                // Push parameter frame
                final int push = cpg.addMethodref(TRANSLET_CLASS,
                                                  PUSH_PARAM_FRAME,
                                                  PUSH_PARAM_FRAME_SIG);
                il.append(classGen.loadTranslet());
                il.append(new INVOKEVIRTUAL(push));
                translateContents(classGen, methodGen);
            }
        }

        // Generate a valid Java method name
        final String className = stylesheet.getClassName();
        String methodName = Util.escape(_name.toString());

        // Load standard arguments
        il.append(classGen.loadTranslet());
        il.append(methodGen.loadDOM());
        il.append(methodGen.loadIterator());
        il.append(methodGen.loadHandler());
        il.append(methodGen.loadCurrentNode());

        // Initialize prefix of method signature
        StringBuffer methodSig = new StringBuffer("(" + DOM_INTF_SIG
            + NODE_ITERATOR_SIG + TRANSLET_OUTPUT_SIG + NODE_SIG);

        // If calling a simply named template, push actual arguments
        if (_calleeTemplate != null) {
            Vector calleeParams = _calleeTemplate.getParameters();
            int numParams = _parameters.length;

            for (int i = 0; i < numParams; i++) {
                SyntaxTreeNode node = (SyntaxTreeNode)_parameters[i];
                methodSig.append(OBJECT_SIG);   // append Object to signature

                // Push 'null' if Param to indicate no actual parameter specified
                if (node instanceof Param) {
                    il.append(ACONST_NULL);
                }
                else {  // translate WithParam
                    node.translate(classGen, methodGen);
                }
            }
        }

        // Complete signature and generate invokevirtual call
        methodSig.append(")V");
        il.append(new INVOKEVIRTUAL(cpg.addMethodref(className,
                                                     methodName,
                                                     methodSig.toString())));

        // Do not need to call Translet.popParamFrame() if we are
        // calling a simple named template.
        if (_calleeTemplate == null && (stylesheet.hasLocalParams() || hasContents())) {
            // Pop parameter frame
            final int pop = cpg.addMethodref(TRANSLET_CLASS,
                                             POP_PARAM_FRAME,
                                             POP_PARAM_FRAME_SIG);
            il.append(classGen.loadTranslet());
            il.append(new INVOKEVIRTUAL(pop));
        }
    }

    /**
     * Return the simple named template which this CallTemplate calls.
     * Return false if there is no matched template or the matched
     * template is not a simple named template.
     */
    public Template getCalleeTemplate() {
        Template foundTemplate
            = getXSLTC().getParser().getSymbolTable().lookupTemplate(_name);

        return foundTemplate.isSimpleNamedTemplate() ? foundTemplate : null;
    }

    /**
     * Build the list of effective parameters in this CallTemplate.
     * The parameters of the called template are put into the array first.
     * Then we visit the WithParam children of this CallTemplate and replace
     * the Param with a corresponding WithParam having the same name.
     */
    private void buildParameterList() {
        // Put the parameters from the called template into the array first.
        // This is to ensure the order of the parameters.
        Vector defaultParams = _calleeTemplate.getParameters();
        int numParams = defaultParams.size();
        _parameters = new Object[numParams];
        for (int i = 0; i < numParams; i++) {
            _parameters[i] = defaultParams.elementAt(i);
        }

        // Replace a Param with a WithParam if they have the same name.
        int count = elementCount();
        for (int i = 0; i < count; i++) {
            Object node = elementAt(i);

            // Ignore if not WithParam
            if (node instanceof WithParam) {
                WithParam withParam = (WithParam)node;
                QName name = withParam.getName();

                // Search for a Param with the same name
                for (int k = 0; k < numParams; k++) {
                    Object object = _parameters[k];
                    if (object instanceof Param
                        && ((Param)object).getName().equals(name)) {
                        withParam.setDoParameterOptimization(true);
                        _parameters[k] = withParam;
                        break;
                    }
                    else if (object instanceof WithParam
                        && ((WithParam)object).getName().equals(name)) {
                        withParam.setDoParameterOptimization(true);
                        _parameters[k] = withParam;
                        break;
                    }
                }
            }
        }
     }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java CallTemplate.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.