AngularJS watch service value change instead of scope inheritance - angularjs

Question

I just give a try to AngularJS. I try to do something quite simple but I'd like to do it the good way.
I got a list of items in a table which displays name and quantity for each item.
I have a form under the table.
When I click on an item name from the table I'd like the given item to be updatable through the form.
I achieve to do thing with scope inheritance as in fiddle http://jsfiddle.net/5cRte/1/
View :
<tr ng-repeat="item in items">
<td>{{item.name}}</td>
<td>{{item.quantity}}</td>
</tr>
Controllers :
function ItemListController($scope){
$scope.items = [{name:'item1', quantity:10}, {name:'item2', quantity:5}];
$scope.selectCurrentItem = function(currentItem) {
$scope.currentItem = currentItem;
}
}
function ItemFormController($scope){
$scope.$watch('currentItem', function() {
$scope.item = $scope.currentItem;
});
}
But has I read in some topics, it is not a good practice to couple controllers scopes this way, and preferably I'll wan't to use a service to store variables shared between controllers.
I was able to put a static variable in a service and retrieve it in another controller, but I can't make it updated when clicking on the item from the table, as watch not working on services variable. Have you an hint, for this ?
Thanks in advance

Answer 1

I don't know whether this is optimal but this what I could come up with
angular.module('myApp', []);
angular.module('myApp').factory('myService', function(){
var items = [{name:'item1', quantity:10}, {name:'item2', quantity:5}, {name:'item3', quantity:50}];
var current = {};
return {
getItems: function(){
return items;
},
setCurrentItem: function(item){
current.item = item;
},
removeCurrentItem: function(){
delete current.item;
},
getCurrent: function(){
return current;
}
}
});
function ItemListController($scope, myService){
$scope.items = myService.getItems();
$scope.selectCurrentItem = function(currentItem) {
myService.setCurrentItem(currentItem);
}
}
function ItemFormController($scope, myService){
$scope.current = myService.getCurrent();
}
Demo: Fiddle