I have a two Symfony forms:

```
ShoppingListForm
ShoppingListItemForm

```

I'm embedding the ShoppingListItemForm inside the ShoppingListForm many times. i.e. A shopping list contains many items.

So the ShoppingListItemForm consists of two widgets:

```
item_id (checkbox) 
shopping_list_id (hidden - foreign key)

```

What I would like to do is delete the corresponding ShoppingListItem object if the object exists and the checkbox is left unchecked.

I'm not sure how this delete would occur? Would I use a post validator to see which fields have/haven't been checked? I'm a bit lost on this one.