C#•7mo ago

Refresh object in EntityFramework

Hi, I have the situation where multiple users can work on the same order. There is a possibility that the order will be finalized and other user can still make changes, because I'm checking Order.IsFinalized, but it is not updated before. How do I refresh object with current data?

public async Task UpdateAsync(Order updatedOrder)
    {

        var order = await dbContext.Orders
            .Include(order => order.OrderDates)
            .Include(order => order.OrderPositions)
            .FirstOrDefaultAsync(x => x.OrderId == updatedOrder.OrderId)
            ?? throw new DbException("Order not found!");

        await dbContext.Entry(order).ReloadAsync();

        if (updatedOrder.IsFinalized) throw new DbException("Cannot update finalized updatedOrder!");

        updatedOrder.DraftModificationDate = DateTime.Now;

        dbContext.Entry(updatedOrder).State = EntityState.Modified;

        try
        {
            await dbContext.SaveChangesAsync();
        }
        catch (Exception e)
        {
            throw new DbException("Cannot update updatedOrder!", e);
        }
    }

public async Task UpdateAsync(Order updatedOrder)
    {

        var order = await dbContext.Orders
            .Include(order => order.OrderDates)
            .Include(order => order.OrderPositions)
            .FirstOrDefaultAsync(x => x.OrderId == updatedOrder.OrderId)
            ?? throw new DbException("Order not found!");

        await dbContext.Entry(order).ReloadAsync();

        if (updatedOrder.IsFinalized) throw new DbException("Cannot update finalized updatedOrder!");

        updatedOrder.DraftModificationDate = DateTime.Now;

        dbContext.Entry(updatedOrder).State = EntityState.Modified;

        try
        {
            await dbContext.SaveChangesAsync();
        }
        catch (Exception e)
        {
            throw new DbException("Cannot update updatedOrder!", e);
        }
    }

I tried doing something like this, but the order is not updating.

15 Replies

mikibanan•7mo ago

Order is refreshing but it does not update Becuase I suppose it is updated with the data loaded from db

Keswiik•7mo ago

Shouldn't you be checking order.IsFinalized instead of updatedOrder.IsFinalized? From the way this reads, updatedOrder is the user-modified instance and order is freshly loaded at the beginning of the method.

Jimmacle•7mo ago

what behavior are you expecting here? should any changes after an order is finalized be rejected? this doesn't seem like a problem of refreshing, but of rejecting the second request entirely because it's not valid behavior to modify a finalized order

Keswiik•7mo ago

It seems to me that they checked the wrong Order instance, assumed the data was stale, and then attempted to reload the entity as a fix (but that isn't working because they're still checking the wrong instance for the IsFinalized flag)

mikibanan•7mo ago

I mean the thing is that EntityFramework stores e.g. Orders DbSet and it is not updated. When I'm refreshing the DbContext it does not update, because it is updated from the database, so it is the same value

Jimmacle•7mo ago

you shouldn't be using the same dbcontext instance for getting and saving in this instance IMO those are 2 different logical requests get order -> some indeterminate amount of editing time -> update order

mikibanan•7mo ago

I have the lifetime oof the context set to scoped, so it's known blazor's bug

Jimmacle•7mo ago

it's not a bug blazor server scopes last the whole lifetime of the signalr session that's just how it works you need to use IDbContextFactory

mikibanan•7mo ago

Yes but the fact that AddDbContext results in unexpected behaviour in Blazor for me sounds like a bug

Jimmacle•7mo ago

it sounds like a bug if you haven't researched how blazor server works

mikibanan•7mo ago

I'll try this ContextFactory

Jimmacle•7mo ago

it's either that or come up with some other system to create more realistic per-request scopes i do that with mediatr and create a new service scope for each mediatr request but i also don't touch the dbcontext directly from any blazor code

mikibanan•7mo ago

So do I, it's a call from the repository What is mediatr?

Jimmacle•7mo ago

https://github.com/jbogard/MediatR

GitHub

GitHub - jbogard/MediatR: Simple, unambitious mediator implementati...

Simple, unambitious mediator implementation in .NET - GitHub - jbogard/MediatR: Simple, unambitious mediator implementation in .NET

Jimmacle•7mo ago

it's not directly applicable to your problem this is the main bit of how i work around blazor scoping issues

public async Task<T> Send<T>(IRequest<T> request)
{
    using var scope = await CreateScope();
    return await scope.ServiceProvider.GetRequiredService<IMediator>().Send(request);
}

private async Task<IServiceScope> CreateScope()
{
    var scope = _scopeFactory.CreateScope();
    var authState = await _authState.GetAuthenticationStateAsync();
    scope.ServiceProvider.GetRequiredService<CurrentUserService>().User = authState.User;
    return scope;
}

public async Task<T> Send<T>(IRequest<T> request)
{
    using var scope = await CreateScope();
    return await scope.ServiceProvider.GetRequiredService<IMediator>().Send(request);
}

private async Task<IServiceScope> CreateScope()
{
    var scope = _scopeFactory.CreateScope();
    var authState = await _authState.GetAuthenticationStateAsync();
    scope.ServiceProvider.GetRequiredService<CurrentUserService>().User = authState.User;
    return scope;
}

yes i make my own scopes with blackjack and hookers in my specific use case it works fine™️ but i'm going to switch to a proper client+api eventually so there is a strict separation

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Refresh object in EntityFramework