private async Task EditPerson(ParentWithChildren parentWithChildren)
{
//in a real world app you would pass _people in and allow the selectable items source to dynamically change
var editor = new RelationEditor(parentWithChildren, _people.Items.ToArray());
//TODO: Investigate why selectable state is being held onto ny the Dialog
await DialogHost.Show(editor, (object sender, DialogClosingEventArgs eventArgs) =>
{
//use the .Edit method as it is more efficient when apply multiple changes
_relations.Edit(innerCache =>
{
//extract the new relations
var newRelations = editor.Children
.Where(c => c.IsSelected).Select(selectable => new Relation(parentWithChildren.Parent, (Person)selectable))
.ToArray();
//remove old ones
var toRemove = innerCache
.Items.Where(r => r.Parent == parentWithChildren.Parent && !newRelations.Contains(r))
.ToArray();
innerCache.Remove(toRemove);
innerCache.AddOrUpdate(newRelations);
});
});
}
public ParentWithChildrenProxy(ParentWithChildren personWithChildren, Action <ParentWithChildren> editAction)
{
_personWithChildren = personWithChildren;
var children = personWithChildren.Children;
ChildrenNames = children.Length == 0 ? "<None>" : string.Join(", ", children.Select(p => p.Name).OrderBy(s => s));
EditCommand = new Command(() => editAction(personWithChildren));
}
public RelationEditor(ParentWithChildren parentWithChildren, Person[] people)
{
Name = parentWithChildren.Parent.Name;
Children = new ObservableCollection <SelectablePerson>
(
people.Where(p => p.Name != parentWithChildren.Parent.Name)
.Select(person => new SelectablePerson(person, parentWithChildren.Children.Contains(person)))
);
}