Angular.js: Storing variable from http.get request to use globally in different $scope function

I am trying to implement Infinite scroll in my Ionic/Cordova mobile application. My nextBatch variable holds the url to the next set of objects I need to fetch once the user hits the bottom of the page. The only problem is, when I try to access it in my loadMoreData() functions it comes out as undefined. I've tried using $rootScope only to get the same result. Any ideas how I should handle this?

Thanks!

.controller('HomeCtrl', function($scope,Model) {

        var nextBatch; //holds the url of the next batch
        $scope.model = []; //used in ng-repeat

        //loads an array of 5 objects
        Model.getAll().success(function(model){
            nextBatch        = model.meta.next; //for infinite scrolling 
            $scope.model     = model.objects; 
        })

        $scope.loadMoreData = function() {
            if (nextBatch !== undefined) {
                Model.getMore(nextBatch).then(function(model){
                   $scope.model.push(favours);
                   $scope.$broadcast('scroll.infiniteScrollComplete');
                })      
            }
};

 })

Here is how you can make synchronizing your infinite scroll. I mean blocking the loadMore until the first call (getAll is finished).

.controller('HomeCtrl', function($scope, Model, $q) {
  var nextBatch; //holds the url of the next batch
  $scope.model = []; //used in ng-repeat

  var defer = $q.defer();
  var promise = defer.promise;

  //loads an array of 5 objects
  Model.getAll().then(function(model){
      nextBatch        = model.meta.next; //for infinite scrolling 
      $scope.model     = model.objects;
      defer.resolve(model);
      return defer.promise;
  });

  $scope.loadMoreData = function() {
      promise.then(function(result){
          if(nextBatch !== "END"){
            Model.getMore(nextBatch).then(function(favours){
              angular.forEach(favours.objects, function(item){
                $scope.model.push(item);
              });
              nextBatch = favours.meta.next;
            });
          }    
      });
  };
})

http://plnkr.co/edit/qohKNUd48czYKASNqCVP