Simple AngularJS Form is undefined in Scope

Question

I'm starting to play around with AngularJS forms in jsfiddle and I've come across a problem already where a very simple form example is not working as expected. All I have is a named form and it's not showing up in scope for some reason (I'm expecting a FormController instance).

I have a fiddle set up, and below is the basic code:

HTML

<div id="mainContainer" ng-app="angularTest" ng-controller="MainCtrl">
    <h1>The Form</h1>
    <form name="theForm">
        <input name="myName" type="text" ng-model="model.name" />
        <input name="submit" type="submit" />
    </form>
</div>

JS

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

app.controller('MainCtrl', ['$scope', function($scope) {
    $scope.model = { name: 'Model Name' };
    console.log($scope.theForm); //displays 'undefined'
}]);

I can't find a lot of straightforward examples of this on jsfiddle, so I wasn't sure if this could be some strange interaction with sites like it (most examples I find aren't using formal controllers). I've tried on Plunker to check as well, but I encounter the same problem.

I'm sure I'm missing something super obvious, but I can't see many other things to change or tweak here. Any help is greatly appreciated!

Answer 1

A good way to perform this without using watch (which is a bit overkill) is to define an object in the scope into which you will register the form.

HTML

<div id="mainContainer" ng-app="angularTest" ng-controller="MainCtrl">
    <h1>The Form</h1>
    <form name="form.theForm">
        <input name="myName" type="text" ng-model="model.name" />
        <input type="button" value="Here the scope" ng-click="display()"/>
        <input name="submit" type="submit" />
    </form>
</div>

JS

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

app.controller('MainCtrl', ['$scope', function($scope) {
    $scope.model = { name: 'Model Name' };
    $scope.form = {};
    $scope.display = function () {
        console.log($scope.form.theForm);
    }
}]);

Answer 2

The form only registers itself with the $scope of the controller after the controller has initially run. Therefore the console.log($scope.theForm) will return undefined even if everything is setup correctly.

In your example to react to the presence of theForm, you can setup a watcher on theForm to set debug text depending its presence:

$scope.$watch('theForm', function(theForm) {
    if(theForm) { 
        $scope.formDebugText = 'Form in Scope';
    }
    else {
        $scope.formDebugText = 'Form is Undefined';
    }        
});

which can be seen in action at http://jsfiddle.net/9k2Jk/1/

Answer 3

What fixed it for me was to use a parent object on the $scope.

In the controller:

$scope.forms = {};
$scope.registerUser = function registerUser() {
    if ($scope.forms.userForm.$valid) {
        alert('submit');
    }
};

In the template:

<form name="forms.userForm" ng-submit="registerUser()">

The reason:

If you use <form name="userForm"... instead of <form name="forms.userForm"... it attaches the form to a child scope, but because $scopes use prototypical inheritance, as soon as I declared an empty object literal on the original $scope the form was attached to it instead.