Devlog #6

These past days I’ve been focused on cleaning up the auth code and setting up frontend-backend communication.

IScopeFactory - Singletons and Scoped Objects

.NET (modern C#) features native dependency injection, where abstractions can be mapped directly to a class, in order to allow that class to receive its required objects from an external source in a more efficient and cleaner manner.

In ASP.NET Core C#, you can register classes as a couple of different types of services to be injected into other classes. I mainly use singletons and scoped objects. Singletons, like their name suggests, are long-lived classes, of which a single instance exists throughout the application’s lifecycle. By contrast, scoped objects are created once per client request before being destroyed.

The problem is that when you use dependency injection, you cannot inject a shorter-lifespan class into a longer-lifespan class (e.g. a scoped into a singleton). This necessitates the use of IServiceScopeFactory to automatically manage the lifetimes of these child classes.

Thread-Safe Singletons

By default, the System.Collections.Generic library in C# is NOT threadsafe. That means that, if multiple scoped objects or singletons access the same Dictionary, that could throw an error. Thus, I switched them out for ConcurrentDictionaries throughout my app.

Multi-Account Functionality Integration

I further integrated functionality that allows my app to store MULTIPLE accounts per provider (e.g. 3 OneDrive accounts, 4 Google Drive accounts). This required refactoring the CloudToken object to include a new AccountId prop, retrieving that prop from the OAuth2.0 protocol, and rewriting some logic in TokenManager to include AccountId validity checks.

RevokeOAuthSync

I added a method to revoke OAuth by terminating the refresh and access tokens using the revoke OAuth2.0 endpoint.

Frontend-Backend Communication

With the basics of the auth protocol API and TokenManager API setup, I’ve begun attempting to facilitate API calls between the React Vite frontend and the ASP.NET Core C# backend. It’s still a WIP, but things are moving! I also added some additional UI to allow the user to select and manage their accounts on different providers.