DateAdd for ActionScript

following yesterday’s theme, in which I built a dateDiff method for AS2, today I extended the class with a static method to provide dateAdd() functionality.  Again, its modeled on the behavior of the CFML dateAdd, so it takes as arguments datePart:String, date:Date, numToAdd:Number.  The method returns a new date object.  To implement it, you can add the following methods to the class from yesterday.

public static function dateAdd(datePart:String,date:Date,num:Number):Date{
  // get date part object;
  var dpo : Object = getDateAddPartHashMap()[datePart.toLowerCase()];
  // create new date as a copy of date passed in
  var newDate : Date = new Date(date.getFullYear(),date.getMonth(),date.getDate(),date.getHours(),date.getMinutes(),date.getSeconds(),date.getMilliseconds());
  // set the appropriate date part of the new date
  newDate[dpo.set](date[dpo.get]()+num);
  // return the new date
  return newDate;
 }
 private static function getDateAddPartHashMap():Object{
  var dpHashMap : Object = new Object();
  dpHashMap[“s”] = new Object();
  dpHashMap[“s”].get = “getSeconds”;
  dpHashMap[“s”].set = “setSeconds”;
  dpHashMap[“n”] = new Object();
  dpHashMap[“n”].get = “getMinutes”;
  dpHashMap[“n”].set = “setMinutes”;
  dpHashMap[“h”] = new Object();
  dpHashMap[“h”].get = “getHours”;
  dpHashMap[“h”].set = “setHours”;
  dpHashMap[“d”] = new Object();
  dpHashMap[“d”].get = “getDate”;
  dpHashMap[“d”].set = “setDate”;
  dpHashMap[“m”] = new Object();
  dpHashMap[“m”].get = “getMonth”;
  dpHashMap[“m”].set = “setMonth”;
  dpHashMap[“y”] = new Object();
  dpHashMap[“y”].get = “getFullYear”;
  dpHashMap[“y”].set = “setFullYear”;
  return dpHashMap;
 }

The complete class now looks like this:

class DateFunction {
 /**
 dateDiff(datePart:String, date1:Date, date2:Date):Number<BR>
 returns the difference between 2 dates<BR>
 valid dateParts:<BR>
 s: Seconds<BR>
 n: Minutes<BR>
 h: Hours<BR>
 d: Days<BR>
 m: Months<BR>
 y: Years<BR>
 */

/** dateAdd(datePart:String,date:Date,num:Number):Date<BR>
 returns a new date object with the appropriate date/time settings<BR>
*/

 public static function dateDiff(datePart:String, date1:Date, date2:Date):Number{
  return getDateDiffPartHashMap()[datePart.toLowerCase()](date1,date2);
 }
 public static function dateAdd(datePart:String,date:Date,num:Number):Date{
  // get date part object;
  var dpo : Object = getDateAddPartHashMap()[datePart.toLowerCase()];
  // create new date as a copy of date passed in
  var newDate : Date = new Date(date.getFullYear(),date.getMonth(),date.getDate(),date.getHours(),date.getMinutes(),date.getSeconds(),date.getMilliseconds());
  // set the appropriate date part of the new date
  newDate[dpo.set](date[dpo.get]()+num);
  // return the new date
  return newDate;
 }
 private static function getDateAddPartHashMap():Object{
  var dpHashMap : Object = new Object();
  dpHashMap[“s”] = new Object();
  dpHashMap[“s”].get = “getSeconds”;
  dpHashMap[“s”].set = “setSeconds”;
  dpHashMap[“n”] = new Object();
  dpHashMap[“n”].get = “getMinutes”;
  dpHashMap[“n”].set = “setMinutes”;
  dpHashMap[“h”] = new Object();
  dpHashMap[“h”].get = “getHours”;
  dpHashMap[“h”].set = “setHours”;
  dpHashMap[“d”] = new Object();
  dpHashMap[“d”].get = “getDate”;
  dpHashMap[“d”].set = “setDate”;
  dpHashMap[“m”] = new Object();
  dpHashMap[“m”].get = “getMonth”;
  dpHashMap[“m”].set = “setMonth”;
  dpHashMap[“y”] = new Object();
  dpHashMap[“y”].get = “getFullYear”;
  dpHashMap[“y”].set = “setFullYear”;
  return dpHashMap;
 }
 private static function getDateDiffPartHashMap():Object{
  var dpHashMap:Object = new Object();
  dpHashMap[“s”] = getSeconds;
  dpHashMap[“n”] = getMinutes;
  dpHashMap[“h”] = getHours;
  dpHashMap[“d”] = getDays;
  dpHashMap[“m”] = getMonths;
  dpHashMap[“y”] = getYears;
  return dpHashMap;
 }
 private static function compareDates(date1:Date,date2:Date):Number{
  return date1.getTime() – date2.getTime();
 }
 private static function getSeconds(date1:Date,date2:Date):Number{
  return Math.floor(compareDates(date1,date2)/1000);
 }
 private static function getMinutes(date1:Date,date2:Date):Number{
  return Math.floor(getSeconds(date1,date2)/60);
 }
 private static function getHours(date1:Date,date2:Date):Number{
  return Math.floor(getMinutes(date1,date2)/60);
 }
 private static function getDays(date1:Date,date2:Date):Number{
  return Math.floor(getHours(date1,date2)/24);
 }
 private static function getMonths(date1:Date,date2:Date):Number{
  var yearDiff = getYears(date1,date2);
  var monthDiff = date1.getMonth() – date2.getMonth();
  if(monthDiff < 0){
   monthDiff += 12;
  }
  if(date1.getDate()< date2.getDate()){
   monthDiff-=1;
  }
  return 12 *yearDiff + monthDiff;
 }
 private static function getYears(date1:Date,date2:Date):Number{
  return Math.floor(getDays(date1,date2)/365);
 }
}