/*
* 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: WithParam.java 468650 2006-10-28 07:03:30Z minchau $
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.PUSH;
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.ReferenceType;
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
* @author John Howard <JohnH@schemasoft.com>
*/
final class WithParam extends Instruction {
/**
* Parameter's name.
*/
private QName _name;
/**
* The escaped qname of the with-param.
*/
protected String _escapedName;
/**
* Parameter's default value.
*/
private Expression _select;
/**
* %OPT% This is set to true when the WithParam is used in a CallTemplate
* for a simple named template. If this is true, the parameters are
* passed to the named template through method arguments rather than
* using the expensive Translet.addParameter() call.
*/
private boolean _doParameterOptimization = false;
/**
* Displays the contents of this element
*/
public void display(int indent) {
indent(indent);
Util.println("with-param " + _name);
if (_select != null) {
indent(indent + IndentIncrement);
Util.println("select " + _select.toString());
}
displayContents(indent + IndentIncrement);
}
/**
* Returns the escaped qname of the parameter
*/
public String getEscapedName() {
return _escapedName;
}
/**
* Return the name of this WithParam.
*/
public QName getName() {
return _name;
}
/**
* Set the name of the variable or paremeter. Escape all special chars.
*/
public void setName(QName name) {
_name = name;
_escapedName = Util.escape(name.getStringRep());
}
/**
* Set the do parameter optimization flag
*/
public void setDoParameterOptimization(boolean flag) {
_doParameterOptimization = flag;
}
/**
* The contents of a <xsl:with-param> elements are either in the element's
* 'select' attribute (this has precedence) or in the element body.
*/
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);
}
setName(parser.getQNameIgnoreDefaultNs(name));
}
else {
reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "name");
}
final String select = getAttribute("select");
if (select.length() > 0) {
_select = parser.parseExpression(this, "select", null);
}
parseChildren(parser);
}
/**
* Type-check either the select attribute or the element body, depending
* on which is in use.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
if (_select != null) {
final Type tselect = _select.typeCheck(stable);
if (tselect instanceof ReferenceType == false) {
_select = new CastExpr(_select, Type.Reference);
}
}
else {
typeCheckContents(stable);
}
return Type.Void;
}
/**
* Compile the value of the parameter, which is either in an expression in
* a 'select' attribute, or in the with-param element's body
*/
public void translateValue(ClassGenerator classGen,
MethodGenerator methodGen) {
// Compile expression is 'select' attribute if present
if (_select != null) {
_select.translate(classGen, methodGen);
_select.startIterator(classGen, methodGen);
}
// If not, compile result tree from parameter body if present.
else if (hasContents()) {
compileResultTree(classGen, methodGen);
}
// If neither are present then store empty string in parameter slot
else {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
il.append(new PUSH(cpg, Constants.EMPTYSTRING));
}
}
/**
* This code generates a sequence of bytecodes that call the
* addParameter() method in AbstractTranslet. The method call will add
* (or update) the parameter frame with the new parameter value.
*/
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Translate the value and put it on the stack
if (_doParameterOptimization) {
translateValue(classGen, methodGen);
return;
}
// Make name acceptable for use as field name in class
String name = Util.escape(getEscapedName());
// Load reference to the translet (method is in AbstractTranslet)
il.append(classGen.loadTranslet());
// Load the name of the parameter
il.append(new PUSH(cpg, name)); // TODO: namespace ?
// Generete the value of the parameter (use value in 'select' by def.)
translateValue(classGen, methodGen);
// Mark this parameter value is not being the default value
il.append(new PUSH(cpg, false));
// Pass the parameter to the template
il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
ADD_PARAMETER,
ADD_PARAMETER_SIG)));
il.append(POP); // cleanup stack
}
}