habitica/website/public/js/directives/from-now.directive.js

'use strict';

angular
  .module('habitrpg')
  .directive('fromNow', fromNow);

fromNow.$inject = [
  '$interval',
  '$timeout'
];

function fromNow($interval, $timeout) {
  return function(scope, element, attr){
    var interval, timeout;

    var updateText = function(){
      element.text(moment(scope.message.timestamp).fromNow());
    };

    var setupInterval = function() {
      if(interval) $interval.cancel(interval);
      if(timeout)  $timeout.cancel(timeout);

      var diff = moment().diff(scope.message.timestamp, 'minute');

      if(diff < 60) {
        // Update every minute
        interval = $interval(updateText, 60000, false);
        timeout = $timeout(setupInterval, diff * 60000);
      } else {
        // Update every hour
        interval = $interval(updateText, 3600000, false);
      }
    };

    updateText();
    setupInterval();

    scope.$on('$destroy', function() {
      if(interval) $interval.cancel(interval);
      if(timeout)  $timeout.cancel(timeout);
    });
  }
}