action-reducer | simple ActionCreator and Reducer library | Frontend Framework library

For future archeologists, the best solution I could come up with was to add Fluxor's IActionSubscriber via DI into my component (with the virtualized list which is managed by a redux state) and subscribe to the success/failure actions dispatched when the LoadDtosActionEffect attempts to talk to the API to retrieve the DTOs. The component declares a simple boolean flag which is immediately set to true in LoadDtosAsync, the actions registered with the action subscriber simply set this flag to false when the success/failure actions are dispatched.

I suspect, since Blazor WASM is single-threaded, this flag should not be concurrently modified. I discovered this when I tried to use System.Threading.EventWaitHandle to block while waiting for the DTOs to load.

Pro-tip: don't block in Blazor WASM, you will only achieve deadlock in your application.

The biggest note here is to add a timeout to this code, if some future modification breaks the chain of actions/effects upon which the action subscriptions rely, the loop will still exit and simply use the incorrect state. This result is more desirable than slowly building up tons of concurrent "threads" (which aren't really threads) in the async/await schedule which will just end up eating cycles and killing performance.

The resulting code to wait for an action (or subsequent effects/actions dispatched) to complete: