Hands-On Mobile Development with .NET Core

Observable repository

In the previous example, the responsibility of choosing between the remote data and the local data fell onto the view model. If we could actually notify the view-model about the changing result (that is, local and remote data), we would need to pass the local repository instance to the view-model. By using reactive extensions, we could implement a notifying observable and subscribe to various events on the view-model:

• OnNext: We would update the data within the view model, which would be fired twice
• OnCompleted: We would hide any progress indicator we have been showing up until this point

Before we can implement the view-model subscriptions, let's implement the GetAuction method in a reactive manner:

public IObservable<Auction> ...