/*
* 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: FunctionDef1Arg.java 468655 2006-10-28 07:12:06Z minchau $
*/
package org.apache.xpath.functions;
import org.apache.xalan.res.XSLMessages;
import org.apache.xml.dtm.DTM;
import org.apache.xml.utils.XMLString;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XString;
import org.apache.xpath.res.XPATHErrorResources;
/**
* Base class for functions that accept one argument that can be defaulted if
* not specified.
* @xsl.usage advanced
*/
public class FunctionDef1Arg extends FunctionOneArg
{
static final long serialVersionUID = 2325189412814149264L;
/**
* Execute the first argument expression that is expected to return a
* nodeset. If the argument is null, then return the current context node.
*
* @param xctxt Runtime XPath context.
*
* @return The first node of the executed nodeset, or the current context
* node if the first argument is null.
*
* @throws javax.xml.transform.TransformerException if an error occurs while
* executing the argument expression.
*/
protected int getArg0AsNode(XPathContext xctxt)
throws javax.xml.transform.TransformerException
{
return (null == m_arg0)
? xctxt.getCurrentNode() : m_arg0.asNode(xctxt);
}
/**
* Tell if the expression is a nodeset expression.
* @return true if the expression can be represented as a nodeset.
*/
public boolean Arg0IsNodesetExpr()
{
return (null == m_arg0) ? true : m_arg0.isNodesetExpr();
}
/**
* Execute the first argument expression that is expected to return a
* string. If the argument is null, then get the string value from the
* current context node.
*
* @param xctxt Runtime XPath context.
*
* @return The string value of the first argument, or the string value of the
* current context node if the first argument is null.
*
* @throws javax.xml.transform.TransformerException if an error occurs while
* executing the argument expression.
*/
protected XMLString getArg0AsString(XPathContext xctxt)
throws javax.xml.transform.TransformerException
{
if(null == m_arg0)
{
int currentNode = xctxt.getCurrentNode();
if(DTM.NULL == currentNode)
return XString.EMPTYSTRING;
else
{
DTM dtm = xctxt.getDTM(currentNode);
return dtm.getStringValue(currentNode);
}
}
else
return m_arg0.execute(xctxt).xstr();
}
/**
* Execute the first argument expression that is expected to return a
* number. If the argument is null, then get the number value from the
* current context node.
*
* @param xctxt Runtime XPath context.
*
* @return The number value of the first argument, or the number value of the
* current context node if the first argument is null.
*
* @throws javax.xml.transform.TransformerException if an error occurs while
* executing the argument expression.
*/
protected double getArg0AsNumber(XPathContext xctxt)
throws javax.xml.transform.TransformerException
{
if(null == m_arg0)
{
int currentNode = xctxt.getCurrentNode();
if(DTM.NULL == currentNode)
return 0;
else
{
DTM dtm = xctxt.getDTM(currentNode);
XMLString str = dtm.getStringValue(currentNode);
return str.toDouble();
}
}
else
return m_arg0.execute(xctxt).num();
}
/**
* Check that the number of arguments passed to this function is correct.
*
* @param argNum The number of arguments that is being passed to the function.
*
* @throws WrongNumberArgsException if the number of arguments is not 0 or 1.
*/
public void checkNumberArgs(int argNum) throws WrongNumberArgsException
{
if (argNum > 1)
reportWrongNumberArgs();
}
/**
* Constructs and throws a WrongNumberArgException with the appropriate
* message for this function object.
*
* @throws WrongNumberArgsException
*/
protected void reportWrongNumberArgs() throws WrongNumberArgsException {
throw new WrongNumberArgsException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_ZERO_OR_ONE, null)); //"0 or 1");
}
/**
* Tell if this expression or it's subexpressions can traverse outside
* the current subtree.
*
* @return true if traversal outside the context node's subtree can occur.
*/
public boolean canTraverseOutsideSubtree()
{
return (null == m_arg0) ? false : super.canTraverseOutsideSubtree();
}
}