Dynamic validation and name in a form with AngularJS - angularjs

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

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 2

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>

Answer 3

The problem should be fixed in AngularJS 1.3, according to this discussion on Github.
Meanwhile, here's a temporary solution created by #caitp and #Thinkscape:
// Workaround for bug #1404
// https://github.com/angular/angular.js/issues/1404
// Source: http://plnkr.co/edit/hSMzWC?p=preview
app.config(['$provide', function($provide) {
$provide.decorator('ngModelDirective', function($delegate) {
var ngModel = $delegate[0], controller = ngModel.controller;
ngModel.controller = ['$scope', '$element', '$attrs', '$injector', function(scope, element, attrs, $injector) {
var $interpolate = $injector.get('$interpolate');
attrs.$set('name', $interpolate(attrs.name || '')(scope));
$injector.invoke(controller, this, {
'$scope': scope,
'$element': element,
'$attrs': attrs
});
}];
return $delegate;
});
$provide.decorator('formDirective', function($delegate) {
var form = $delegate[0], controller = form.controller;
form.controller = ['$scope', '$element', '$attrs', '$injector', function(scope, element, attrs, $injector) {
var $interpolate = $injector.get('$interpolate');
attrs.$set('name', $interpolate(attrs.name || attrs.ngForm || '')(scope));
$injector.invoke(controller, this, {
'$scope': scope,
'$element': element,
'$attrs': attrs
});
}];
return $delegate;
});
}]);
Demo on JSFiddle.

Answer 4

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 5

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 6

I expand the #caitp and #Thinkscape solution a bit, to allow dynamically created nested ng-forms, like this:
<div ng-controller="ctrl">
<ng-form name="form">
<input type="text" ng-model="static" name="static"/>
<div ng-repeat="df in dynamicForms">
<ng-form name="form{{df.id}}">
<input type="text" ng-model="df.sub" name="sub"/>
<div>Dirty: <span ng-bind="form{{df.id}}.$dirty"></span></div>
</ng-form>
</div>
<div><button ng-click="consoleLog()">Console Log</button></div>
<div>Dirty: <span ng-bind="form.$dirty"></span></div>
</ng-form>
</div>
Here is my demo on JSFiddle.

Answer 7

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 8

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 9

if we set dynamic name for a input like the below
<input name="{{dynamicInputName}}" />
then we have use set validation for dynamic name like the below code.
<div ng-messages="login.dynamicInputName.$error">
<div ng-message="required">
</div>
</div>