Angular Validation

by Zuhaib Siddiqui

HTML

<div ng-app="myApp">
<form name="form" class="css-form" novalidate>
  <div>
    Size (integer 0 - 10):
    <input type="number" ng-model="size" name="size"
           min="0" max="10" integer />{{size}}<br />
    <span ng-show="form.size.$error.integer">The value is not a valid integer!</span>
    <span ng-show="form.size.$error.min || form.size.$error.max">
      The value must be in range 0 to 10!</span>
  </div>

  <div>
    Username:
    <input type="text" ng-model="name" name="name" username />{{name}}<br />
    <span ng-show="form.name.$pending.username">Checking if this name is available...</span>
    <span ng-show="form.name.$error.username">This username is already taken!</span>
  </div>

</form>
</div>

JavaScript

var app = angular.module('myApp', []);

var INTEGER_REGEXP = /^\-?\d+$/;
app.directive('integer', function() {
  return {
    require: 'ngModel',
    link: function(scope, elm, attrs, ctrl) {
      ctrl.$validators.integer = function(modelValue, viewValue) {
        if (ctrl.$isEmpty(modelValue)) {
          // consider empty models to be valid
          return true;
        }

        if (INTEGER_REGEXP.test(viewValue)) {
          // it is valid
          return true;
        }

        // it is invalid
        return false;
      };
    }
  };
});

app.directive('username', function($q, $timeout) {
  return {
    require: 'ngModel',
    link: function(scope, elm, attrs, ctrl) {
      var usernames = ['Jim', 'John', 'Jill', 'Jackie'];

      ctrl.$asyncValidators.username = function(modelValue, viewValue) {

        if (ctrl.$isEmpty(modelValue)) {
          // consider empty model valid
          return $q.when();
        }

        var def = $q.defer();

        $timeout(function() {
          // Mock a delayed response
          if (usernames.indexOf(modelValue) === -1) {
            // The username is available
            def.resolve();
          } else {
            def.reject();
          }

        }, 2000);

        return def.promise;
      };
    }
  };
});