Updating an Object in the Local Database in MAUI .NET 9 [GamesCatalog] - Part 11

Previous part: Adding Objects to a Local Database in MAUI .NET 9 [GamesCatalog] - Part 10

Step 1. In GameRepo, add a function to retrieve a game from the local database using igdbId and another function to update the game's status.

Code

public async Task<GameDTO?> GetByIGDBIdAsync(int igdbId)
{
    using var context = DbCtx.CreateDbContext();
    return await context.Games.FirstOrDefaultAsync(g => g.IGDBId == igdbId);
}
public async Task UpdateStatusAsync(int id, DateTime updatedAt, GameStatus status, int? rate)
{
    using var context = DbCtx.CreateDbContext();

    await context.Games
        .Where(x => x.Id == id)
        .ExecuteUpdateAsync(y => y
            .SetProperty(z => z.UpdatedAt, updatedAt)
            .SetProperty(z => z.Status, status)
            .SetProperty(z => z.Rate, rate));
}

Press [Ctrl + .] on GetByIGDBIdAsync and UpdateStatusAsync, then add them to the interface.

Step 2. In GameService, add both functions.

Code

public async Task<GameDTO?> GetByIGDBIdAsync(int igdbId) => 
    await GameRepo.GetByIGDBIdAsync(igdbId);
public async Task UpdateStatusAsync(int id, GameStatus gameStatus, int? rate) => 
    await GameRepo.UpdateStatusAsync(id, DateTime.Now, gameStatus, rate);

Press [Ctrl + .] on GetByIGDBIdAsync and UpdateStatusAsync, then add them to the interface.

Step 3. Add a variable for the local game ID.

Step 4. Still in AddGameVM, create a function to retrieve the game.

public async Task BuildGameStatus()
{
    var gameDTO = await gameService.GetByIGDBIdAsync(int.Parse(IgdbId));
    if (gameDTO is null) 
        return;
    Id = gameDTO.Id;
    switch (gameDTO.Status)
    {
        case GameStatus.Want:
            _ = Want();
            break;
        case GameStatus.Playing:
            _ = Playing();
            break;
        case GameStatus.Played:
            _ = Played();
            Rate = gameDTO.Rate;
            break;
    }
}

Step 5. Call this function asynchronously using ApplyQueryAttributes.

Code

public void ApplyQueryAttributes(IDictionary<string, object> query)
{
    if (query is not null && query.TryGetValue("Game", out object? game))
    {
        if (game is not null and UIIGDBGame uiGame)
        {
            Game = uiGame;
            IgdbId = Game.Id;
            Name = Game.Name;
            ReleaseDate = Game.ReleaseDate;
            CoverUrl = Game.CoverUrl;
            Platforms = Game.Platforms;
            Summary = Game.Summary;
            _ = BuildGameStatus();
        }
    }
}

Step 6. Modify the confirmation command to update the game's status.

[RelayCommand]
public async Task Confirm()
{
    // Disable button to avoid multiple requests
    ConfirmIsEnabled = false;
    int? _rate = null;
    string displayMessage;
    // If the game is played, the rate is required
    if (GameSelectedStatus == GameStatus.Played)
        _rate = Rate;
    if (Id is null)
    {
        if (IsOn && CoverUrl is not null)
            _ = IGDBGamesApiService.SaveImageAsync(CoverUrl, $"{IgdbId}.jpg");
        GameDTO game = new()
        {
            IGDBId = int.Parse(IgdbId),
            Name = Name,
            ReleaseDate = ReleaseDate,
            CoverUrl = CoverUrl,
            Platforms = Platforms,
            Summary = Summary,
            Status = GameSelectedStatus.Value,
            Rate = _rate,
        };
        await gameService.CreateAsync(game);
        displayMessage = "Status Added!";
    }
    else
    {
        await gameService.UpdateStatusAsync(Id.Value, GameSelectedStatus.Value, _rate);
        displayMessage = "Status Updated!";
    }
    if (DeviceInfo.Platform == DevicePlatform.iOS || DeviceInfo.Platform == DevicePlatform.Android)
    {
        ToastDuration duration = ToastDuration.Short;
        var toast = Toast.Make(displayMessage, duration, 15);
        await toast.Show();
    }
    else
    {
        await Application.Current.Windows[0].Page.DisplayAlert("Success", displayMessage, null, "Ok");
    }

    await Shell.Current.GoToAsync("..");
    ConfirmIsEnabled = true;
}

Step 7. With this, we can now update already registered games.

In Android

Next part: We will begin creating the app’s main screen.