setPristine is not a function - angularjs

Question

I got my angular form all setup and working. The values are set after calling a response to a json request. The form is succesfully populated with the json response. After that i want to 'reset' the form, as in $scope.object.$setPristine. But i get an error:
$scope.object.$setPristine is not a function
I'm using angular 1.4.8.
Here is my HTML:
<div ng-app="myApp" ng-controller="formController" class="ng-scope">
<form name="object" ng-submit="submit()" method="post" action="" novalidate="" class="ng-pristine ng-valid">
<div class="form-group">
<label class="control-label" for="object_name">Name</label>
<input type="text" id="object_name" name="object[name]" ng-model="object.name" class="form-control ng-pristine ng-valid ng-touched" value="Object 2c">
</div>
<div class="form-group">
<label class="control-label" for="object_elements">Elements</label>
<select id="object_elements" name="object[elements][]" ng-model="object.elements" ng-options="opt.id as opt.name for opt in options | orderBy: "id"" class="form-control ng-pristine ng-untouched ng-valid" multiple="multiple"></select></div>
<div class="form-group">
<input ng-disabled="object.$pristine" class="btn btn-primary" value="Save" ng-click="submitForm()">
</div>
</form>
</div>
And here is my .js:
var app = angular.module('myApp', ["ngResource"]).controller('formController', function ($scope, $http, $location) {
var url = $location.absUrl() + '/json'
$http({
method: 'GET',
url: url
}).then(function (response) {
$scope.status = response.status;
$scope.data = response.data;
$scope.object = response.data;
$scope.object.$setPristine();
$('#modal-loading').modal('hide');
}, function (response) {
$scope.data = response.data || "Request failed";
$scope.status = response.status;
$('#modal-loading').modal('hide');
});
});

Answer 1

You overwrite $scope.object with a JSON response, of course it doesn't have any functions attached to it.
$scope.object = response.data;
$scope.object.$setPristine();
This is functionally the same as:
$scope.object = {of_course: "this doesn't work"};
$scope.object.$setPristine();
You probably just need to change your ng-models to reference $scope.data instead of $scope.object
ng-model="data.name"
and then not overwrite your form object.

Answer 2

My way is this...
<form name="newClntForm" id="newClnt" class="add(newClnt, newClntForm)">
<input type="text" class="form-control" ng-model="newClnt.name" placeholder="Contact Person Name" required >
</form>
And Controller Save Function is
function(newClnt, newClntForm){
angular.copy({},newClnt);
// newClntForm is form name
newClntForm.$setPristine();
newClntForm.$setUntouched();
};