code: function(trigger, target){
                      target.classList.toggle('hide');
                      var targetWidth = target.offsetWidth;
                      var targetHeight = target.offsetHeight;
                      target.classList.toggle('hide');
                      var triggerWidth = trigger.offsetWidth;
                      var triggerHeight = trigger.offsetHeight;
                      switch($scope.dropDirection){
                          case 'left': {
                              left = getTriggerOffset().left - targetWidth - 10 + 'px';
                              top = getTriggerOffset().top + 'px';
                              break;
                          }
  
                          case 'right':{
                              left = getTriggerOffset().left + triggerWidth + 10 + 'px';
                              top = getTriggerOffset().top + 'px';
                              break;
                          } 
  
                          case'top':{
                              left = getTriggerOffset().left + 'px';
                              top = getTriggerOffset().top - targetHeight - 10 + 'px';
                              break;
                          }
  
                          default:{
                              left = getTriggerOffset().left +'px';
                              top = getTriggerOffset().top + triggerHeight + 10 + 'px'
                          }
                      }
                      target.style.position = 'absolute';
                      target.style.left = left;
                      target.style.top = top;
                  }
docs: calculates the position of the popover