angluarjs trigger $http on model update

I am building a TODO-lists app using Angularjs, nodejs and mongoose.
What I want to do is to trigger ajax when watched model changes.

I noticed the well known todomvc use the following code

$scope.$watch('todos', function () {
    $scope.remainingCount = filterFilter(todos, {
        completed: false
    }).length;
    $scope.doneCount = todos.length - $scope.remainingCount;
    $scope.allChecked = !$scope.remainingCount;
    todoStorage.put(todos);
}, true);

However I have a TODO detail panel, and I use x-editable to in-place edit the title. The model is referenced by app.currentTodo.

Currently I use

$scope.$watch('currentTodo', function(){ $http... });

Is there a better way?