Avalonia Music Store App

An amateur's take on the AvaloniaUI Music Store App Tutorial project using Microsoft's CommunityToolkit.Mvvm framework.

CommunityToolkit

I wanted to use the community toolkit to become more familiar with its concepts since it now comes as an MVVM framework option for new Avalonia projects.
It cuts out a lot of the boilerplate code that the tutorial uses, but libraries like ReactiveUI.Fody can help with that too.

I have used Avalonia with ReactiveUI in the past but never to an advanced level.

Inversion of Control

I separated out a lot of business logic away from the Album model, put them into services, and then injected them using Microsoft.Extensions.DependencyInjection. Most of the services just implement a single method but could be expanded upon.

I'm honestly not sure if I set up the IServiceProvider in the right place but it seems to do the job.

Services

IAlbumSearchService

Dedicated to finding available albums and returning a list of them.
Implemented with iTunesAlbumSearchService to use the iTunes API just like in the original tutorial.

IAlbumCoverService

Dedicated to getting the cover image for a given Album.
Implemented with HttpAlbumCoverService to use an HttpClient to download images from the Album.CoverUrl if it does not find one stored in a local "Cache" folder.

IAlbumDataService

Dedicated to saving and loading lists of Album.
Implemented with JsonAlbumDataService to serialize and deserialize lists of Album and save/load them to a local file.

IAlbumViewModelFactory

One issue I came across is that because the Album models are now dumb and don't store the Image for the cover themselves, I needed a way to get the Album and cover Image to the AlbumViewModel at the same time without giving it access directly to the DI container. I solved this by creating a IAlbumViewModelFactory service that uses the current IAlbumCoverService from the DI container.

Unit Testing

This was my first project that properly implemented Depedency Injection so I ended up using it to learn about Unit Testing too.
I used Xunit, which comes built-in to Visual Stuido; FluentAssertions, which lets your write "fluent" (readable) assertions; and FakeItEasy, to fake implementations for my services.

Adding unit tests really made me have to rethink how I approached my services and how they were used, mostly because I could not unit test static classes or extention methods.

Summary

I had a lot of fun doing this tutorial project. I had to think a lot about how to do things in the community toolkit that were being done with ReactiveUI in the tutorial. I think it worked out really well with the inclusion of HanumanInstitute.MvvmDialogs.Avalonia to handle the MusicStoreView dialog window. I was originally going to use DialogHost.Avalonia with it but because the tutorial opted to open a whole new window, I didn't feel the need to include it.

I feel like I over-did it with all of the services but I also feel like they all cover specific tasks that don't necessarily need to go together.