Dynamic validation and name in a form with Angular

Question

I have this form : http://jsfiddle.net/dfJeN/

As you can see the name value for the input is statically set :

name="username"

, the form validation works fine (add something and remove all text from the input, a text must appears).

Then I try to dynamically set the name value : http://jsfiddle.net/jNWB8/

name="{input.name}"

Then I apply this to my validation

login.{{input.name}}.$error.required

(this pattern will be used in an ng-repeat) but my form validation is broken. It is correctly interpreted in my browser (if I inspect the element I saw login.username.$error.required).

Any Idea ?

EDIT: After logging the scope in the console it appears that the

{{input.name}}

expression is not interpolate. My form as an {{input.name}} attribute but no username.

UPDATE: Since 1.3.0-rc.3 name="{{input.name}}" works as expected. Please see #1404

Answer 1

Nice one by @EnISeeK.... but i got it to be more elegant and less obtrusive to other directives:

.directive("dynamicName",[function(){
    return {
        restrict:"A",
        require: ['ngModel', '^form'],
        link:function(scope,element,attrs,ctrls){
            ctrls[0].$name = scope.$eval(attrs.dynamicName) || attrs.dynamicName;
            ctrls[1].$addControl(ctrls[0]);
        }
    };
}])

Answer 2

You can't do what you're trying to do that way.

Assuming what you're trying to do is you need to dynamically add elements to a form, with something like an ng-repeat, you need to use nested ng-form to allow validation of those individual items:

<form name="outerForm">
<div ng-repeat="item in items">
   <ng-form name="innerForm">
      <input type="text" name="foo" ng-model="item.foo" />
      <span ng-show="innerForm.foo.$error.required">required</span>
   </ng-form>
</div>
<input type="submit" ng-disabled="outerForm.$invalid" />
</form>

Sadly, it's just not a well-documented feature of Angular.

Answer 3

Just a little improvement over EnlSeek solution

angular.module('test').directive('dynamicName', ["$parse", function($parse) {
 return {
    restrict: 'A',
    priority: 10000, 
    controller : ["$scope", "$element", "$attrs", 
           function($scope, $element, $attrs){
         var name = $parse($attrs.dynamicName)($scope);
         delete($attrs['dynamicName']);
         $element.removeAttr('data-dynamic-name');
         $element.removeAttr('dynamic-name');
          $attrs.$set("name", name);
    }]

  };
}]);

Here is a plunker trial. Here is detailed explantion

Answer 4

I used Ben Lesh's solution and it works well for me. But one problem I faced was that when I added an inner form using ng-form, all of the form states e.g. form.$valid, form.$error etc became undefined if I was using the ng-submit directive.

So if I had this for example:

<form novalidate ng-submit="saveRecord()" name="outerForm">
    <!--parts of the outer form-->
    <ng-form name="inner-form">
      <input name="someInput">
    </ng-form>
    <button type="submit">Submit</button>
</form>

And in the my controller:

$scope.saveRecord = function() {
    outerForm.$valid // this is undefined
}

So I had to go back to using a regular click event for submitting the form in which case it's necessary to pass the form object:

<form novalidate name="outerForm">  <!--remove the ng-submit directive-->
    <!--parts of the outer form-->
    <ng-form name="inner-form">
      <input name="someInput">
    </ng-form>
    <button type="submit" ng-click="saveRecord(outerForm)">Submit</button>
</form>

And the revised controller method:

$scope.saveRecord = function(outerForm) {
    outerForm.$valid // this works
}

I'm not quite sure why this is but hopefully it helps someone.

Answer 5

This issue has been fixed in Angular 1.3+ This is the correct syntax for what you are trying to do:

login[input.name].$invalid

Answer 6

Using nested ngForm allows you to access the specific InputController from within the HTML template. However, if you wish to access it from another controller it does not help.

e.g.

<script>
  function OuterController($scope) {
    $scope.inputName = 'dynamicName';

    $scope.doStuff = function() {
      console.log($scope.formName.dynamicName); // undefined
      console.log($scope.formName.staticName); // InputController
    }
  }
</script>

<div controller='OuterController'>
  <form name='myForm'>
    <input name='{{ inputName }}' />
    <input name='staticName' />
  </form>
  <a ng-click='doStuff()'>Click</a>
</div>

I use this directive to help solve the problem:

angular.module('test').directive('dynamicName', function($compile, $parse) {
  return {
    restrict: 'A',
    terminal: true,
    priority: 100000,
    link: function(scope, elem) {
      var name = $parse(elem.attr('dynamic-name'))(scope);
      // $interpolate() will support things like 'skill'+skill.id where parse will not
      elem.removeAttr('dynamic-name');
      elem.attr('name', name);
      $compile(elem)(scope);
    }
  };
});

Now you use dynamic names wherever is needed just the 'dynamic-name' attribute instead of the 'name' attribute.

e.g.

<script>
  function OuterController($scope) {
    $scope.inputName = 'dynamicName';

    $scope.doStuff = function() {
      console.log($scope.formName.dynamicName); // InputController
      console.log($scope.formName.staticName); // InputController
    }
  }
</script>

<div controller='OuterController'>
  <form name='myForm'>
    <input dynamic-name='inputName' />
    <input name='staticName' />
  </form>
  <a ng-click='doStuff()'>Click</a>
</div>