Angular, input field with a currency mask directive for money format on the fly

Push a $parser to the controller, and only update the value when it doesn't match the input using $setViewValue() and $render().

app.directive('currencyInput', function() {
    return {
      require: '?ngModel',
      link: function($scope, element, attrs, controller) {
        return ctrl.$parsers.push(function(inputValue) {

            ...

            if (result != inputValue) {
                controller.$setViewValue(res);
                controller.$render();
            }
        });
      }
    };
});

Here's a fiddle with the logic I used for my currency input directive: Fiddle

From your example I don't see that link returns something.

I would write directive something like:

.directive('format', ['$filter', function ($filter) {
    return {
        require: '?ngModel',
        link: function (scope, elem, attrs, ctrl) {
            if (!ctrl) return;


            ctrl.$formatters.unshift(function (a) {
                return $filter(attrs.format)(ctrl.$modelValue)
            });


            ctrl.$parsers.unshift(function (viewValue) {

          elem.priceFormat({
            prefix: '',
            centsSeparator: ',',
            thousandsSeparator: '.'
        });                

                return elem[0].value;
            });
        }
    };
}]);

Demo 1 Fiddle

If you want on start fire the filter, use $formatters:

Now link is:

link: function (scope, elem, attrs, ctrl) {
            if (!ctrl) return;

            var format = {
                    prefix: '',
                    centsSeparator: ',',
                    thousandsSeparator: ''
                };

            ctrl.$parsers.unshift(function (value) {
                elem.priceFormat(format);

                return elem[0].value;
            });

            ctrl.$formatters.unshift(function (value) {
                elem[0].value = ctrl.$modelValue * 100 ;
                elem.priceFormat(format);
                return elem[0].value;
            })
        }

Demo 2 Fiddle

Late to the party, but I believe this deserves another answer! I've been using the ng-currency module. It's absolutely fantastic.