gistfile1.txt

app.controller('ItemsUpdateController', function ($scope, item, Items, $state) {
    $scope.item = item;
    $scope.item.$loaded().then(function(data) {
        $scope.item = data;   
    });
    $scope.add = function() {
       var item = {};
       item.$id = $scope.item.$id;
       item.title = $scope.item.title;
       item.ingredients = $scope.item.ingredients;
       item.price = $scope.item.price;
       item.url = $scope.item.url;
       console.log(item.$id);// this is -J_C-1R8sb13Nqb-7jO6 but I've got Error: Firebase.set failed: First argument contains an invalid key ($id). Keys must be non-empty strings and can't contain ".", "#", "$", "/", "[", or "]"
       console.log(Items.update(item.$id,item));/*.then(function () {
            $state.transitionTo('items');
        });*/ $state.transitionTo('items');
    }
});