Angularjs prevent form submission when input validation fails

You can do:

<form name="loginform" novalidate ng-submit="loginform.$valid && login.submit()">

No need for controller checks.

Change the submit button to:

<button type="submit" ng-disabled="loginform.$invalid">Login</button>

So the suggested answer from TheHippo did not work for me, instead I ended up sending the form as a parameter to the function like so:

<form name="loginform" novalidate ng-submit="login.submit(loginForm)" class="css-form">

This makes the form available in the controller method:

$scope.login = {
    submit : function(form) {
        if(form.$valid)....
    }