ÿþ/*********************************************************
 *	File:		  date_util.js
 *	Author:		MetaDesign
 *	Created:	March 7, 2007
 *
 *	Description:
 *	Enhances date capabilities in javascript.
 *  Used by calendar controls.
 ********************************************************/



/*--------------------------------------------------------------

 * Static Method: isLeapYear

 *

 * Determines if a year is a leap year.

 *

 * Parameters:

 * pYear    integer   4 digit year

 *

 * Return:

 * boolean    true if pYear is a leap year

 *------------------------------------------------------------*/
Date.isLeapYear = function(pYear) {

  if (0 == pYear % 400) return true;

  if (0 == pYear % 100) return false;

  return (0 == pYear % 4) ? true : false;

}



/*--------------------------------------------------------------

 * Method: isLeapYear

 *

 * Determines if a date is in a leap year.

 *

 * Parameters:

 * None

 *

 * Return:

 * boolean    true if the date is in a leap year

 *------------------------------------------------------------*/
Date.prototype.isLeapYear = function() {

  return Date.isLeapYear(this.getFullYear());

}



/*--------------------------------------------------------------

 * Static Method: getDaysInMonth

 *

 * Returns the number of days in a given month/year.

 *

 * Parameters:

 * pMonth   integer   month index (0 to 11)

 * pYear    integer   4 digit year

 *

 * Return:

 * integer    The number of days in pMonth/pYear

 *------------------------------------------------------------*/
Date.getDaysInMonth = function(pMonth, pYear) {

  var monthDays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

  // Handle all months except February

  if (pMonth != 1) return monthDays[pMonth];

  // Handle February

  return (Date.isLeapYear(pYear)) ? monthDays[pMonth] + 1 : monthDays[pMonth];

}



/*--------------------------------------------------------------

 * Method: getDaysInMonth

 *

 * Returns the number of days in the month of the given date.

 *

 * Parameters:

 * None

 *

 * Return:

 * integer    The number of days in the month of the given date

 *------------------------------------------------------------*/
Date.prototype.getDaysInMonth = function() {

  return Date.getDaysInMonth(this.getMonth(), this.getFullYear());

}



/*--------------------------------------------------------------

 * Method: getPrevMonth

 *

 * Returns a date representing the first day of the previous month.

 *

 * Parameters:

 * None

 *

 * Return:

 * date     The first day of the previous month

 *------------------------------------------------------------*/
Date.prototype.getPrevMonth = function() {

  var currMonth = this.getMonth();

  var currYear = this.getFullYear();

  return (currMonth == 0) ? new Date(currYear - 1, 11, 1) : new Date(currYear, currMonth - 1, 1);

}



/*--------------------------------------------------------------

 * Method: getNextMonth

 *

 * Returns a date representing the first day of the next month.

 *

 * Parameters:

 * None

 *

 * Return:

 * date     The first day of the next month

 *------------------------------------------------------------*/
Date.prototype.getNextMonth = function() {

  var currMonth = this.getMonth();

  var currYear = this.getFullYear();

  return (currMonth == 11) ? new Date(currYear + 1, 0, 1) : new Date(currYear, currMonth + 1, 1);

}





/*--------------------------------------------------------------

 * Method: getPrevDate

 *

 * Returns a date representing the day before.

 *

 * Parameters:

 * None

 *

 * Return:

 * date     The day before the given date

 *------------------------------------------------------------*/
Date.prototype.getPrevDate = function() {

  var currYear = this.getFullYear();

  var currMonth = this.getMonth();

  var currDate = this.getDate();



  if (currDate == 1) {

    if (currMonth == 0) {

      // For Jan 1

      return new Date(currYear - 1, 11, 31);

    } else {

      // For first of the month not including Jan

      return new Date(currYear, currMonth - 1, Date.getDaysInMonth(currMonth - 1, currYear));

    }

  } else {

    return new Date(currYear, currMonth, currDate - 1);

  }

}



/*--------------------------------------------------------------

 * Method: getNextDate

 *

 * Returns a date representing the day after.

 *

 * Parameters:

 * None

 *

 * Return:

 * date     The day after the given date

 *------------------------------------------------------------*/
Date.prototype.getNextDate = function() {

  var currYear = this.getFullYear();

  var currMonth = this.getMonth();

  var currDate = this.getDate();

  

  if (currDate == this.getDaysInMonth()) {

    if (currMonth == 11) {

      // For Dec 31

      return new Date(currYear + 1, 0, 1);

    } else {

      // For last day of the month not including Dec

      return new Date(currYear, currMonth + 1, 1);

    }

  } else {

    return new Date(currYear, currMonth, currDate + 1);

  }

}





/*--------------------------------------------------------------

 * Static Method: isSameMonthYear

 *

 * Determines if two dates are in the same month and year.

 *

 * Parameters:

 * pDateA   date    The first date to compare

 * pDateB   date    The second date to compare

 *

 * Return:

 * boolean    True if both dates are in the same month and year

 *------------------------------------------------------------*/
Date.isSameMonthYear = function(pDateA, pDateB) {

  return (pDateA.getFullYear() == pDateB.getFullYear()) && (pDateA.getMonth() == pDateB.getMonth());

}



/*--------------------------------------------------------------

 * Static Method: getDayName

 *

 * Returns the name of the day ("Sunday", "Monday", etc.).

 *

 * Parameters:

 * pDay   integer   The day index (0 to 7)

 *

 * Return:

 * string   The full name of the day

 *------------------------------------------------------------*/
Date.getDayName = function(pDay) {

  var dayNames = Date.getDayNames();

  return dayNames[pDay];

}



/*--------------------------------------------------------------

 * Method: getDayName

 *

 * Returns the name of the given date ("Sunday", "Monday", etc.).

 *

 * Parameters:

 * None

 *

 * Return:

 * string   The full name of the given date

 *------------------------------------------------------------*/
Date.prototype.getDayName = function() {

  return Date.getDayName(this.getDay());

}



/*--------------------------------------------------------------

 * Static Method: getDayAbbreviation

 *

 * Returns the abbreviated name of the day ("S", "M", etc.).

 *

 * Parameters:

 * pDay   integer   The day index (0 to 7)

 *

 * Return:

 * string   The single character abbreviated name of the day

 *------------------------------------------------------------*/
Date.getDayAbbreviation = function(pDay) {

  var dayAbbrevs = Date.getDayAbbreviations();

  return dayAbbrevs[pDay];

}



/*--------------------------------------------------------------

 * Method: getDayAbbreviation

 *

 * Returns the abbreviated name of the given date ("S", "M", etc.).

 *

 * Parameters:

 * None

 *

 * Return:

 * string   The single character abbreviated name of the given

 *          date

 *------------------------------------------------------------*/
Date.prototype.getDayAbbreviation = function() {

  return Date.getDayAbbreviation(this.getDay());

}



/*--------------------------------------------------------------

 * Static Method: getMonthName

 *

 * Returns the name of the month ("January", "February", etc.).

 *

 * Parameters:

 * pMonth   integer   The month index (0 to 11)

 *

 * Return:

 * string   The full name of the month

 *------------------------------------------------------------*/
Date.getMonthName = function(pMonth) {

  var monthNames = Date.getMonthNames();

  return monthNames[pMonth];

}



/*--------------------------------------------------------------

 * Method: getMonthName

 *

 * Returns the name of the month for the given date

 * ("January", "February", etc.).

 *

 * Parameters:

 * None

 *

 * Return:

 * string   The full name of the month for the given date

 *------------------------------------------------------------*/
Date.prototype.getMonthName = function() {

  return Date.getMonthName(this.getMonth());

}



/*--------------------------------------------------------------

 * Static Method: getMonthAbbreviation

 *

 * Returns the abbreviated name of the month ("Jan", "Feb", etc.).

 *

 * Parameters:

 * pMonth   integer   The month index (0 to 11)

 *

 * Return:

 * string   The three character abbreviated name of the month

 *------------------------------------------------------------*/
Date.getMonthAbbreviation = function(pMonth) {

  var monthAbbrevs = Date.getMonthAbbreviations();

  return monthAbbrevs[pMonth];

}



/*--------------------------------------------------------------

 * Method: getMonthAbbreviation

 *

 * Returns the abbreviated name of the month for the given date

 * ("Jan", "Feb", etc.).

 *

 * Parameters:

 * None

 *

 * Return:

 * string   The three character abbreviated name of the month

 *          for the given date

 *------------------------------------------------------------*/
Date.prototype.getMonthAbbreviation = function() {

  return Date.getMonthAbbreviation(this.getMonth());

}



// TODO:  Enhancement - Separate string arrays into separate constants file to be localized for japanese and chinese.



/*--------------------------------------------------------------

 * Static Method: getDayNames

 *

 * Returns an array of day names.

 *

 * Parameters:

 * None

 *

 * Return:

 * array    Array of day names in index order

 *------------------------------------------------------------*/
Date.getDayNames = function() {

  return ["åeÜfåe", "gÜfåe", "kpÜfåe", "4lÜfåe", "(gÜfåe", "Ñ‘Üfåe", "WÜfåe"];

}



/*--------------------------------------------------------------

 * Static Method: getDayAbbreviations

 *

 * Returns an array of single character day name abbreviations.

 *

 * Parameters:

 * None

 *

 * Return:

 * array    Array of single character day name abbreviations in

 *          index order

 *------------------------------------------------------------*/
Date.getDayAbbreviations = function() {

  return ["åe", "g", "kp", "4l", "(g", "Ñ‘", "W"];

}



/*--------------------------------------------------------------

 * Static Method: getMonthNames

 *

 * Returns an array of month names.

 *

 * Parameters:

 * None

 *

 * Return:

 * array    Array of month names in index order

 *------------------------------------------------------------*/
Date.getMonthNames = function() {

  return ["1g", "2g", "3g", "4g", "5g", "6g", "7g", "8g", "9g", "10g", "11g", "12g"];

}



/*--------------------------------------------------------------

 * Static Method: getMonthAbbreviations

 *

 * Returns an array of three character month name abbreviations.

 *

 * Parameters:

 * None

 *

 * Return:

 * array    Array of three character month name abbreviations in

 *          index order

 *------------------------------------------------------------*/
Date.getMonthAbbreviations = function() {

  return ["1g", "2g", "3g", "4g", "5g", "6g", "7g", "8g", "9g", "10g", "11g", "12g"];

}