Javascript regExp to accept 12 digits before decimal and two digits after decimal

Question

Can anyone tell me the javascript regEx to accept 12 numbers before decimal and to allow only 2 digits after decimal.In case the number does not have any decimal, the text box should accept max of 12 numbers.The value should be only numbers. I already have a directive where i am performing all the javascript validations.Please let me know what else should be added.

The directive-

.directive('allowOnlyDigits', function () {
    return {
        require: '?ngModel',
        scope: { currencycode: '=' },
        link: function(scope, element, attrs, ngModelCtrl) {
          if(!ngModelCtrl) {
            return; 
          }

          ngModelCtrl.$parsers.push(function(val) {
            if (angular.isUndefined(val)) {
                var val = '';
            }


            var decimalCheck = clean.split('.');

            if(!angular.isUndefined(decimalCheck[1])) {
                decimalCheck[1] = decimalCheck[1].slice(0,2);
                clean = decimalCheck[0] + '.' + decimalCheck[1];
            }

            if (val !== clean) {
              ngModelCtrl.$setViewValue(clean);
              ngModelCtrl.$render();
            }
            return clean;
          });

          element.bind('keypress', function(event) {
            if(event.keyCode === 32) {
              event.preventDefault();
            }
          });
        }
      };
    })

Answer 1

This is the RegEx you are looking for: /^\\d{1,12}(\\.\\d{1,2})?$/

Demo (try it yourself):

 var input = document.getElementsByTagName("input")[0] input.oninput = function() { document.getElementById("output").textContent = /^\\d{1,12}(\\.\\d{1,2})?$/.test(input.value) } 

 <input type="text" /> <div id="output"></div>