angularjs - Firebase angularfire child.$asObject give properties undefined

Question

I've got this code:

factory

app.factory('Items', function($firebase,FIREBASE_URL) {
    var ref = new Firebase(FIREBASE_URL);
    var items = $firebase(ref.child('items')).$asArray();
    var Item = {
        all: function () {
          return items;
        },
        create: function (item) {
          return items.$add(item);
        },
        get: function (itemId) {
          return $firebase(ref.child('items').child(itemId)).$asObject();
        },
        update: function (itemId, item) {
          return $firebase(ref.child('items').child(itemId)).update(item);
        },
        delete: function (item) {
          return items.$remove(item);
        }
    };
    return Item;
});

route

app.config(function($stateProvider) {
    $stateProvider      
        .state('items_update', {
            url: '/items/update/:id',
            templateUrl: 'views/items/form.html',
            controller:'ItemsUpdateController',
            resolve:{
                item:function(Items,$stateParams){
                    return Items.get($stateParams.id);
                }
            }
        })
});

controller

app.controller('ItemsUpdateController', function ($scope, item, $state) {
    $scope.item = item;
    console.log($scope.item.url);
    $scope.add = function() {
        Items.update($scope.item).then(function () {
            $state.transitionTo('items');
        });
    }
});

why console.log($scope.item.url); give me undefined ?

but in the view I've got all the data

html

<form class="form-horizontal" role="form" name="form" data-ng-submit="add()">
    <div class="form-group">
        <input type="text" name="title" tabindex="1" class="form-control" placeholder="{{ 'items.form.title' | translate }}" data-ng-model="item.title" required="required" data-ng-minlength="3" data-ng-maxlength="25" user-feedback />
    </div>
    <div class="form-group">
        <input type="text" name="ingredients" tabindex="2" class="form-control" placeholder="{{ 'items.form.ingredients' | translate }}" data-ng-model="item.ingredients" required="required" ng-pattern="/^w(s*,?s*w)*$/" user-feedback />
    </div>
    <div class="form-group">
        <input type="text" name="price" tabindex="3" class="form-control" placeholder="{{ 'items.form.price' | translate }}" data-ng-model="item.price" required="required" data-smart-float user-feedback />  
    </div>
    <div class="form-group">
        <button type="button" tabindex="4" class="btn btn-default btn-lg" item="item" data-uploader>{{ 'items.form.upload' | translate }}</button>
        <input type="text" name="url" style="display:none;" required="required" data-ng-model="item.url" />
    </div>
    <div class="form-group form-no-required clearfix">
        <div class="pull-right">
            <button type="submit" tabindex="5" class="btn btn-primary" data-ng-disabled="form.$invalid">{{ 'items.form.submit' | translate }}</button>
        </div>
    </div>
</form>

ENDS UP

as in the @Frank van Puffelen comment I worked it out with:

app.controller('ItemsUpdateController', function($scope, item, $state) {
    item.$loaded().then(function(data) {
        $scope.item = data;  
        console.log($scope.item.url);
    });
    $scope.add = function() {
        Items.update($scope.item).then(function() {
            $state.transitionTo('items');
        });
    }
});

Answer 1

Waitting for answers