How do I restrict an input to only accept numbers?

Question

I am using ngChange in AngularJS to trigger a custom function that will remove any letters the user adds to the input.

Answer 1

Here's my implementation of the $parser solution that @Mark Rajcok recommends as the best method. It's essentially @pkozlowski.opensource's excellent $parser for text answer but rewritten to only allow numerics. All credit goes to him, this is just to save you the 5 minutes of reading that answer and then rewriting your own:

app.directive('numericOnly', function(){
    return {
        require: 'ngModel',
        link: function(scope, element, attrs, modelCtrl) {

            modelCtrl.$parsers.push(function (inputValue) {
                var transformedInput = inputValue ? inputValue.replace(/[^\d.-]/g,'') : null;

                if (transformedInput!=inputValue) {
                    modelCtrl.$setViewValue(transformedInput);
                    modelCtrl.$render();
                }

                return transformedInput;
            });
        }
    };
});

And you'd use it like this:

Interestingly, spaces never reach the parser unless surrounded by an alphanumeric, so you'd have to .trim() as needed. Also, this parser does NOT work on . For some reason, non-numerics never make it to the parser where they'd be removed, but they do make it into the input control itself.