AngularJS Form controller from directive - angularjs

Question

I am trying to submit a simple contact form. The form is inside a bootstrap modal (don't think that makes any difference) but the controller is in a directive.
The html for the form is as followed:
<form name="contactForm" ng-submit="contactForm()" novalidate>
<div class="form-group">
<div class="col-lg-6 col-md-6 col-sm-6">
<input type="text" placeholder="Full name" name="name" ng-minlength="3" max="20"
ng-model="name" id="name" class="form-control">
</div>
<div class="col-lg-6 col-md-6 col-sm-6">
<input type="email" ng-minlength="4" placeholder="Email address" name="contactEmail"
ng-model="email" class="form-control">
</div>
</div>
<div class="form-group">
<div class="col-lg-12 col-md-12 col-sm-12">
<input type="text" ng-model="subject" name="subject" ng-minlength="10" id=""
placeholder="Subject" class="form-control">
</div>
</div>
<div class="form-group">
<div class="col-lg-12 col-md-12 col-sm-12">
<textarea class="form-control" ng-model="message" name="message" ng-minlength="10"
placeholder="Your message"></textarea>
</div>
</div>
<div class="modal-footer">
<div class="col-lg-12 col-md-12 col-sm-12">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
<input type="submit" class="btn btn-primary" value="Submit" />
</div>
</div>
</form>
Which i think is all good. The body of my controller looks like this
$rootScope.contactForm = contactForm();
function contactForm() {
console.log('triggered!');
var contactFormVars = {
name: $rootScope.name,
contactEmail: $rootScope.contactEmail,
subject: $rootScope.subject,
message: $rootScope.message
}
// With Promise
Stamplay.Object('contactform')
.save(contactFormVars)
.then(function(res) {
console.log('yes!');
}, function(err) {
console.log('No!');
})
}
return directive;
};
EDIT: Controller now looks like this:
function contactForm($rootScope,$stamplay,$q) {
$rootScope.data = {}
$rootScope.data = {
name: $rootScope.data.name,
contactemail: $rootScope.data.contactemail,
subject: $rootScope.data.subject,
message: $rootScope.data.message
}
Stamplay.Object("contactform")
.save($rootScope.data, function (err, res) {
console.log(res);
console.log(err);
// res is the new car object
});
}
When i click the submit button I get the following error which i've been Googling
Error: v2.contactForm is not a function. (In 'v2.contactForm()', 'v2.contactForm' is an instance of FormController)
fn
Any help with this is appreciated.
EDIT
Ok so now i've moved the js from a directive and placed it in to the main controller. At the moment its not making any difference, only that the error has changed very slightly:
angular.js:12722Error: v4.contactForm is not a function. (In 'v4.contactForm(ensureSafeObject(v5,text))', 'v4.contactForm' is an instance of FormController)
fn
Not sure what the difference between v2 and v4 is.
Any advice to get past this blocker is appreciated.