/*
* Copyright 1999,2004 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.
*/
package org.apache.taglibs.standard.lang.jpath.expression;
import java.util.Calendar;
import javax.servlet.jsp.PageContext;
import org.apache.taglibs.standard.lang.jpath.adapter.ConversionException;
import org.apache.taglibs.standard.lang.jpath.adapter.Convert;
import org.apache.taglibs.standard.lang.jpath.adapter.IterationContext;
import org.apache.taglibs.standard.lang.jpath.adapter.JSPDate;
/**
* The RollDateFunction class
*
*
* @author <a href='mailto:scott.hasse@isthmusgroup.com'>Scott Hasse</a>
* @version
*/
public class RollDateFunction extends SimpleNode {
/**
* Used to create an instance of the RollDateFunction class
*
*
* @param id
*
*/
public RollDateFunction(int id) {
super(id);
}
/**
* Used to create an instance of the RollDateFunction class
*
*
* @param p
* @param id
*
*/
public RollDateFunction(Parser p, int id) {
super(p, id);
}
/**
* Provides a method to print a normalized version of the original
* expression. The normalized version has standardized spacing and
* parenthesis, and can be used to compare expressions formatted
* in different ways to see if they are actually the same expression.
*
*
* @return The normalized version of the original expression
*
*/
public String toNormalizedString() {
boolean first = true;
String normalized;
normalized = "date-roll(";
if (children != null) {
for (int i = 0; i < children.length; ++i) {
if (!first) {
normalized = normalized + ",";
}
first = false;
SimpleNode n = (SimpleNode) children[i];
if (n != null) {
normalized = normalized + n.toNormalizedString();
}
}
}
normalized = normalized + ")";
return normalized;
}
/**
* This method evaluates this node of the expression and all child nodes.
* It returns the result of the
* evaluation as an <tt>Object</tt>. If any problems are encountered
* during the evaluation, an <tt>EvaluationException</tt> is thrown.
*
*
* @param pageContext the current JSP PageContext
*
* @param icontext the Iteration Context of the expression. If there is
* no interation context, this should be null.
*
* @return the result of the expression evaluation as an object
*
* @throws EvaluationException if a problem is encountered during the
* evaluation
*/
public Object evaluate(PageContext pageContext, IterationContext icontext)
throws EvaluationException {
JSPDate result;
try {
result = Convert.toJSPDate(jjtGetChild(0).evaluate(pageContext,
icontext));
String arg2 =
Convert.toString(jjtGetChild(1).evaluate(pageContext,
icontext));
int arg3 = Convert.toDouble(jjtGetChild(2).evaluate(pageContext,
icontext)).intValue();
int field = getCalendarConstant(arg2);
result.roll(field, arg3);
} catch (ConversionException ce) {
throw new EvaluationException(this, ce.getMessage());
}
return result;
}
/**
* The getCalendarConstant method
*
*
* @param field
*
* @return
*
* @throws EvaluationException
*
*/
private int getCalendarConstant(String field) throws EvaluationException {
int result;
if (field.equals("era")) {
result = Calendar.ERA;
} else if (field.equals("year")) {
result = Calendar.YEAR;
} else if (field.equals("month")) {
result = Calendar.MONTH;
} else if (field.equals("weekOfYear")) {
result = Calendar.WEEK_OF_YEAR;
} else if (field.equals("date")) {
result = Calendar.DATE;
} else if (field.equals("dayOfMonth")) {
result = Calendar.DAY_OF_MONTH;
} else if (field.equals("dayOfYear")) {
result = Calendar.DAY_OF_YEAR;
} else if (field.equals("dayOfWeek")) {
result = Calendar.DAY_OF_WEEK;
} else if (field.equals("dayOfWeekInMonth")) {
result = Calendar.DAY_OF_WEEK_IN_MONTH;
} else if (field.equals("amPm")) {
result = Calendar.AM_PM;
} else if (field.equals("hour")) {
result = Calendar.HOUR;
} else if (field.equals("hourOfDay")) {
result = Calendar.HOUR_OF_DAY;
} else if (field.equals("minute")) {
result = Calendar.MINUTE;
} else if (field.equals("second")) {
result = Calendar.SECOND;
} else if (field.equals("millisecond")) {
result = Calendar.MILLISECOND;
} else {
throw new EvaluationException(this,
"An invalid date field was supplied");
}
return result;
}
}