/*
* @(#)$Id: FunctionAvailableCall.java,v 1.16 2003/01/30 18:46:00 mkwan Exp $
*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 2001, Sun
* Microsystems., http://www.sun.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* @author G. Todd Miller
* @author Santiago Pericas-Geertsen
*
*/
package org.apache.xalan.xsltc.compiler;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Vector;
import org.apache.bcel.generic.ConstantPoolGen;
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.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
import org.apache.xalan.xsltc.compiler.util.Util;
import org.apache.xalan.xsltc.runtime.TransletLoader;
final class FunctionAvailableCall extends FunctionCall {
private Expression _arg;
private String _nameOfFunct = null;
private String _namespaceOfFunct = null;
private boolean _isFunctionAvailable = false;
/**
* Constructs a FunctionAvailableCall FunctionCall. Takes the
* function name qname, for example, 'function-available', and
* a list of arguments where the arguments must be instances of
* LiteralExpression.
*/
public FunctionAvailableCall(QName fname, Vector arguments) {
super(fname, arguments);
_arg = (Expression)arguments.elementAt(0);
_type = null;
if (_arg instanceof LiteralExpr) {
LiteralExpr arg = (LiteralExpr) _arg;
_namespaceOfFunct = arg.getNamespace();
_nameOfFunct = arg.getValue();
if (!isInternalNamespace()) {
_isFunctionAvailable = hasMethods();
}
}
}
/**
* Argument of function-available call must be literal, typecheck
* returns the type of function-available to be boolean.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
if (_type != null) {
return _type;
}
if (_arg instanceof LiteralExpr) {
return _type = Type.Boolean;
}
ErrorMsg err = new ErrorMsg(ErrorMsg.NEED_LITERAL_ERR,
"function-available", this);
throw new TypeCheckError(err);
}
/**
* Returns an object representing the compile-time evaluation
* of an expression. We are only using this for function-available
* and element-available at this time.
*/
public Object evaluateAtCompileTime() {
return getResult() ? Boolean.TRUE : Boolean.FALSE;
}
/**
* for external java functions only: reports on whether or not
* the specified method is found in the specifed class.
*/
private boolean hasMethods() {
LiteralExpr arg = (LiteralExpr)_arg;
// Get the class name from the namespace uri
String className = getClassNameFromUri(_namespaceOfFunct);
// Get the method name from the argument to function-available
String methodName = null;
int colonIndex = _nameOfFunct.indexOf(":");
if (colonIndex > 0) {
String functionName = _nameOfFunct.substring(colonIndex+1);
int lastDotIndex = functionName.lastIndexOf('.');
if (lastDotIndex > 0) {
methodName = functionName.substring(lastDotIndex+1);
if (className != null && !className.equals(""))
className = className + "." + functionName.substring(0, lastDotIndex);
else
className = functionName.substring(0, lastDotIndex);
}
else
methodName = functionName;
}
else
methodName = _nameOfFunct;
if (className == null || methodName == null) {
return false;
}
// Replace the '-' characters in the method name
if (methodName.indexOf('-') > 0)
methodName = replaceDash(methodName);
try {
TransletLoader loader = new TransletLoader();
final Class clazz = loader.loadClass(className);
if (clazz == null) {
return false;
}
else {
final Method[] methods = clazz.getMethods();
for (int i = 0; i < methods.length; i++) {
final int mods = methods[i].getModifiers();
if (Modifier.isPublic(mods)
&& Modifier.isStatic(mods)
&& methods[i].getName().equals(methodName))
{
return true;
}
}
}
}
catch (ClassNotFoundException e) {
return false;
}
return false;
}
/**
* Reports on whether the function specified in the argument to
* xslt function 'function-available' was found.
*/
public boolean getResult() {
if (_nameOfFunct == null) {
return false;
}
if (isInternalNamespace()) {
final Parser parser = getParser();
_isFunctionAvailable =
parser.functionSupported(Util.getLocalName(_nameOfFunct));
}
return _isFunctionAvailable;
}
/**
* Return true if the namespace uri is null or it is the XSLTC translet uri.
*/
private boolean isInternalNamespace() {
return (_namespaceOfFunct == null ||
_namespaceOfFunct.equals(EMPTYSTRING) ||
_namespaceOfFunct.equals(TRANSLET_URI));
}
/**
* Calls to 'function-available' are resolved at compile time since
* the namespaces declared in the stylsheet are not available at run
* time. Consequently, arguments to this function must be literals.
*/
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
methodGen.getInstructionList().append(new PUSH(cpg, getResult()));
}
}