Directive to use arrow keys on forms or tables to quickly jump on to input boxes

arrowKeys.js

angular.module('app.directives')

.directive('arrowKeysIndex', function() {
  return {
    restrict: 'A',
    require: '^ngModel',    
    link: function (scope, element, attrs) {
      element.on('keydown', function(event) {                  
        let currentIndex = attrs.arrowKeysIndex;
        let nextIndex;

        if (currentIndex === '' || currentIndex === null || typeof currentIndex === 'undefined') {
            //don't do anything
        }else{
          let rowColumnIndex = currentIndex.split(':');
          let row;
          let column;

          if(rowColumnIndex.length > 1){
            row = parseInt(rowColumnIndex[0]);
            column = parseInt(rowColumnIndex[1]);
          }else{
            row = parseInt(rowColumnIndex[0]);
          }

          //enter and down key
          if (event.which === 13 || event.which === 40) {
            nextIndex = (row+1)+':'+column;
            event.preventDefault();
          //up key code
          }else if(event.which === 38){
            nextIndex = (row-1)+':'+column;
            event.preventDefault();
          //left key code
          }else if(event.which === 37){
            nextIndex = row+':'+(column-1);
            event.preventDefault();
          //right key code
          }else if(event.which === 39){
            nextIndex = row+':'+(column+1);
            event.preventDefault();
          }

          if(nextIndex){
            var nextInput = angular.element(angular.element.find('[arrow-keys-index="'+nextIndex+'"]'));
            nextInput.focus();
            scope.$apply();
          }
        }
      });
    }
  };
})

arrowKeysExample.html

<table>
  <tr ng-repeat="data in dataRows track by $index">
    <td>
      <input type="text"  arrow-keys-index="{{$index}}:1" ng-model="data.column1" />
    </td>
    <td>
      <input type="text"  arrow-keys-index="{{$index}}:2" ng-model="data.column2" />
    </td>
    <td>
      <input type="text"  arrow-keys-index="{{$index}}:3" ng-model="data.column3" />
    </td>
    <td>
      <input type="text"  arrow-keys-index="{{$index}}:4" ng-model="data.column4" />
    </td>
  </tr>
</table>