Can I access a form in the controller?

The reason you can’t access the input is because the Foundation tab (or ng-repeat?) creates an isolate scope. One way to address this is using the controller as syntax:

<div ng-controller="MyController as ctrl">

<!-- an example of a directive that would create an isolate scope -->
<div ng-if="true">

<form name="ctrl.myForm">
    ...inputs
    Dirty? {{ctrl.myForm.$dirty}}

    <button ng-click="ctrl.saveChanges()">Save</button>
</form>

</div>

</div>

Then you can access the FormController in your code like:

function MyController () {
    var vm = this;
    vm.saveChanges = saveChanges;

    function saveChanges() {

       if(vm.myForm.$valid) { 
            // Save to db or whatever.
            vm.myForm.$setPristine();
       }
}