angular directive ignore non-numeric input

Question

I have to write some code for IE8. I have an ng-repeat creating a table filled with:

Answer 1

HTML:

Directive:

app.directive('productionQty', function() {
  return {
    require: 'ngModel',
    link: function (scope, element, attr, ngModelCtrl) {
      function fromUser(text) {
        var transformedInput = text.replace(/[^0-9]/g, '');
        console.log(transformedInput);
        if(transformedInput !== text) {
            ngModelCtrl.$setViewValue(transformedInput);
            ngModelCtrl.$render();
        }
        return transformedInput;  // or return Number(transformedInput)
      }
      ngModelCtrl.$parsers.push(fromUser);
    }
  }; 
});

Plunker

See also filters on ng-model in an input. My answer above is modeled off pkozlowski.opensource's answer.

I looked at ng-pattern, but it does not filter what is shown in the textbox. It sets $scope.qty1 to undefined, but the undesired characters are visible in the textbox.