Angular directive for limit the max length in input number

digitLimitDirective.js

/*
<input type='number' digit-limit="4" />
*/
.directive("digitLimit", function(){
	return {
		restrict: "A",
		link: function(scope, element, attrs){
			var max = attrs.digitLimit;

			element.bind("keydown", function(e){
				var currentValue = element.val();
				if(currentValue.length >= max && e.keyCode != 8 && e.keyCode != 9){
					e.preventDefault();
				}
			});
		}
	}
})