How can i make Recursion Asynchronous using Async and Await Keyword?

Question

i am getting multi-level dynamic menus from database. Currently i have called it successfully but i want to make it async.
here is my code;

protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
    var menus = Uow.Menus.GetAll()
        .Select(m => new ParentMenuViewModel()
        {
            MenuId = m.MenuId,
            Name = m.Name,
            ParentId = m.ParentId
        })
        .ToList<ParentMenuViewModel>();
    ViewBag.Menus = CreateVM(0, menus);
    base.OnActionExecuting(filterContext);
}

public IEnumerable<ParentMenuViewModel> CreateVM(int parentid, List<ParentMenuViewModel> list)
{
    return list.Where(m=> m.ParentId==parentid)
        .Select(m=> new ParentMenuViewModel()
        {
            MenuId = m.MenuId,
            Name = m.Name,
            ParentId = m.ParentId,
            ChildMenus = CreateVM(m.MenuId, list)
        });
}

So, how can i make this asynchronous using async and await keywords?
Notice that, it loops until the children are loaded completely;
Is it even a good practice to make it async (the above code)?

There is no point in making it async unless you have an actual async operation inside (which you don't) — SLaks, May 19 '13 at 14:35
so, if i mark it as async, this will have no positive feedback? — Idrees Khan, May 19 '13 at 14:38

score 2 · Answer 1 · edited May 23 '17 at 12:05

2

Unfortunately, async action filters are not available (yet); see this question. You can vote here for the MVC team to add this capability.

Once MVC supports async action filters, you could use, e.g., GetAllAsync. The recursive part does not require any async functionality because it's not I/O-bound.

edited May 23 '17 at 12:05

Community

1
1

answered May 19 '13 at 14:38

Stephen Cleary

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what about making the `CreateVM` method async? – Idrees Khan May 19 '13 at 14:39
`CreateVM` would not benefit from being `async`; see my edit. – Stephen Cleary May 19 '13 at 14:39

How can i make Recursion Asynchronous using Async and Await Keyword?

1 Answers1