Chargeback.js

angular.module('chargeback', ['ui.router', 'upload', 'ngAnimate'])
// Lots of code before the directive...
    .directive('test', ['$filter', function($filter){

		// This should handle and input and return 0 or a valid float.
		function toFloat(val){
			var f = parseFloat(val || 0)
			return isFinite(f) ? f : 0;
		}

		// This actually uses the standard Angular filter directive to
		// do that, calling it directly from JS instead of via the DOM.
		// It's equivalent to this in HTML:
		// 	   {{ val | number:2 }}
		function numberFormat(val){
			return $filter("number")(val, 2);
		}

	    return {
	        require: 'ngModel',
	        restrict: 'A',
	        link: function($scope, elem, attrs, ngModel){

			// $formatters read from model value and pass to DOM for
			// display. This ensures that the DOM always displays a "0.00"
	            	ngModel.$formatters.push(numberFormat);

			// $parsers read from the DOM and pass to validator, so
			// need to convert to a float here if need a float in the
			// ngModel value. If you don't need that, then can remove.
			// In this case, we use it so that the $formatter function
			// will always get a number.
	            	ngModel.$parsers.push(toFloat);
	        }
	    };
	}])