Use Javascript To Compare Time Ranges

I have a collection of time ranges in the form of Date objects. I need to compare those time ranges against a new time range to make sure I don't add a time range that overlaps or

Solution 1:

Since this is for an open source project, I was hoping that someone here likes SO points enough to come up with a more "best practice" or more elegant solution than what I did. I guess everyone in the comments hates SO points though.

So here's my solution.

angular.forEach($scope.timeSlots, function (timeSlot, index) {
    var beginTimeHasIssue = ($scope.timeSlot.BeginTime >= timeSlot.BeginTime && $scope.timeSlot.BeginTime <= timeSlot.EndTime);
    var endTimeHasIssue = ($scope.timeSlot.EndTime >= timeSlot.BeginTime && $scope.timeSlot.EndTime <= timeSlot.EndTime);

    if (beginTimeHasIssue || endTimeHasIssue) {
        hasError = true;
        $scope.HasTimeSlotError = true;
        return;
    } 
});

Solution 2:

The way you're doing it is as suggested, however it doesn't seem robust, e.g. if there are no current slots the forEach won't do much. Also, it goes all the way to the end rather than stopping once it's found a slot. Consider the following:

var timeSlots = [
  {BeginTime: newDate("10/25/2015 8:00 AM"),
   EndTime: newDate("10/25/2015 8:45 AM")},
  {BeginTime: newDate("10/25/2015 9:00 AM"),
   EndTime: newDate("10/25/2015 9:45 AM")},
  {BeginTime: newDate("10/25/2015 9:50 AM"),
   EndTime: newDate("10/25/2015 10:30 AM")}
];

/*  @param   {Object} slot - object with BeginTime and EndTime date objects
 **  @returns {Boolean} true if slot fits, otherwise false
 */functionslotFits(slot) {
  if (timeSlots.length == 0) returntrue; // If no slots, must fitreturn timeSlots.some(function(s, i) {
    return (i == 0 && slot.EndTime <= s.BeginTime) || // slot is before all others
      (s.EndTime <= slot.BeginTime && !timeSlots[i + 1]) || // slot is after all others
      (s.EndTime <= slot.BeginTime && timeSlots[i + 1].BeginTime >= slot.EndTime) // Slot between others
  });
}

[{BeginTime: newDate("10/25/2015 7:00 AM"),  // before all, trueEndTime: newDate("10/25/2015 8:00 AM")},
 {BeginTime: newDate("10/25/2015 10:30 AM"),  // after all, trueEndTime: newDate("10/25/2015 11:00 AM")},
 {BeginTime: newDate("10/25/2015 8:45 AM"),  // between 0 and 1, trueEndTime: newDate("10/25/2015 9:00 AM")},
 {BeginTime: newDate("10/25/2015 8:45 AM"),  // Overlap 1, falseEndTime: newDate("10/25/2015 9:15 AM")}
].forEach(function(slot, i) {
  console.log('Slot ' + i + ': ' + slotFits(slot));
});

This could also be optimised to stop once it's passed all chance of finding a slot, requires two more lines of code. You should be able to adapt this to your angular code.

PS. I would not usually create Dates this way using a string (i.e. using the built-in parser for non-standard strings), but it's sufficient for this example. The Dates really should be created using something like:

var date = moment('10/25/2015 9:15 AM', 'MM/DD/YYYY h:mm Z').toDate();

console.log(date.toString());

<scriptsrc="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>

Solution 3:

   addTimeSlot=function(newtimeSlot){
        var beginTimeHasIssue = false;
        var endTimeHasIssue = false;
        timeSlots.forEach(function (timeSlot, index) {
            if( newtimeSlot.BeginTime >= timeSlot.BeginTime &&  newtimeSlot.EndTime <= timeSlot.EndTime ) {
                 console.log('falls inbetween');
                endTimeHasIssue = true;
            } 
            if( newtimeSlot.BeginTime <= timeSlot.BeginTime &&  newtimeSlot.EndTime >= timeSlot.EndTime) {
                 console.log('falls inbetween');
                beginTimeHasIssue = true;
            }      
        });
        if (beginTimeHasIssue || endTimeHasIssue) {
            console.log('error');
            return;
        } else {
            timeSlots.push(newtimeSlot)
            console.log('saved');
        }
        if (timeSlots.length == 0) {
          timeSlots.push(newtimeSlot);
        }
    }