angular-money-directive.js

/**
 * Heavily adapted from the `type="number"` directive in Angular's
 * /src/ng/directive/input.js
 */

angular.module('fiestah.money', [])
.directive('money', function () {
  'use strict';

  var NUMBER_REGEXP = /^\s*(\-|\+)?(\d+|(\d*(\.\d*)))\s*$/;
  function isUndefined(value) {
    return typeof value == 'undefined';
  }
  function isEmpty(value) {
    return isUndefined(value) || value === '' || value === null || value !== value;
  }

  return {
    restrict: 'A',
    require: 'ngModel',
    link: function (scope, el, attr, ctrl) {
      function round(num) { 
        return Math.round(num * 100) / 100;
      }

      var min = parseFloat(attr.min) || 0;

      // Returning NaN so that the formatter won't render invalid chars
      ctrl.$parsers.push(function(value) {

        // Allow "-" inputs only when min < 0
        if (value === '-') {
          ctrl.$setValidity('number', false);
          return (min < 0) ? -0 : NaN;
        }

        var empty = isEmpty(value);
        if (empty || NUMBER_REGEXP.test(value)) {
          ctrl.$setValidity('number', true);
          return value === '' ? null : (empty ? value : parseFloat(value));
        } else {
          ctrl.$setValidity('number', false);
          return NaN;
        }
      });
      ctrl.$formatters.push(function(value) {
        return isEmpty(value) ? '' : '' + value;
      });

      var minValidator = function(value) {
        if (!isEmpty(value) && value < min) {
          ctrl.$setValidity('min', false);
          return undefined;
        } else {
          ctrl.$setValidity('min', true);
          return value;
        }
      };
      ctrl.$parsers.push(minValidator);
      ctrl.$formatters.push(minValidator);

      if (attr.max) {
        var max = parseFloat(attr.max);
        var maxValidator = function(value) {
          if (!isEmpty(value) && value > max) {
            ctrl.$setValidity('max', false);
            return undefined;
          } else {
            ctrl.$setValidity('max', true);
            return value;
          }
        };

        ctrl.$parsers.push(maxValidator);
        ctrl.$formatters.push(maxValidator);
      }

      // Round off to 2 decimal places
      ctrl.$parsers.push(function (value) {
        return value ? round(value) : value;
      });
      ctrl.$formatters.push(function (value) {
        return value ? value.toFixed(2) : value;
      });

      el.bind('blur', function () {
        var value = ctrl.$modelValue;
        if (value) {
          ctrl.$viewValue = round(value).toFixed(2);
          ctrl.$render();
        }
      });
    }
  };
});