DurationCalculator Facade object

[treycarroll]

All,

I am using this DurationCalculator facade object to simplify a duration calculation for the most common use-case that we face.

//@param strDateTime1: string in YYYY-MM-DD hh:mm:ss format
//@param strDateTime2: string in YYYY-MM-DD hh:mm:ss format
//@param scheduleId: sys_id for entry in cmn_schedule.   If omitted, the 8-5 week days excluding holidays schedule will be used
//Never returns a negative number. If strDateTime2 precedes strDateTime1 getDurationSeconds will return zero
//Prevents troublesome off by GMT offset errors
//getDurationSeconds() is the only public method exposed on this object
var u_durationCalculator = function (strDateTime1, strDateTime2, scheduleId) {   
       var outerScope = this;   
       //If they didn't provide a schedule ID default to the 8-5 week days excluding holidays schedule   
       this.scheduleId = (!JSUtil.nil(scheduleId)) ? scheduleId : '090eecae0a0a0b260077e1dfa71da828';     
       this.timeZone = gs.getSession().getTimeZone();   
       this.dt1 = correctStringDateTimeForGMT(strDateTime1);   
       this.dt2 = correctStringDateTimeForGMT(strDateTime2);   
   // Convert the string parameter to GlideDateTime using the assumption that the string provided was user TZ localized and needs to be converted to GMT
       function correctStringDateTimeForGMT(stringDateTime) {   
               var dt = new GlideDateTime(stringDateTime);   
               dt.getLocaltime();   
               var offSetInSeconds = dt.getTZOffset() / 1000; //convert from millis   
               var multiplier = (offSetInSeconds < 0) ? -1 : 1;   
               dt.addSeconds(multiplier * offSetInSeconds);   
               return dt;   
       }   
       function getDurationSeconds() {   
               var dc = new DurationCalculator();   
               dc.setSchedule(outerScope.scheduleId, outerScope.timeZone);   
               var ans = dc.calcScheduleDuration(outerScope.dt1.getDisplayValue(), outerScope.dt2.getDisplayValue());   
               return ans;   
       }   
       return {   
               getDurationSeconds: getDurationSeconds   
       };   
};   
//Example usage   
var dc = new u_durationCalculator ('2016-02-19 12:00:00', '2016-02-22 09:30:00');   
gs.print('Duration Hours:' + dc.getDurationSeconds() / 3600);   
//Output   
*** Script: Duration Hours:6.5   

The "façade " design pattern is used to provide a simplified interface.   Those who have used the existing DateTime function library may have also stumbled into the pitfalls.   I would love it if others were interested in joining me in an effort to create other facade objects for common use-cases involving DateTime calculations.

Godspeed,

Trey Carroll