asp.net core custom IRouter Dependency Injection

Question

I'm creating a custom routing in asp.net core 2, where I check the path in a DB and update action and controller to the desired one.

I have this custom IRouter defined like this

public interface IRouteCustom : IRouter
{
}

public class RouteCustom : IRouteCustom
{
    private readonly IRouter _innerRouter;
    private readonly IMemoryCache _memoryCache;
    private readonly IUnitOfWork _unitOfWork;

    public RouteCustom(IRouter innerRouter, IMemoryCache memoryCache, IUnitOfWork unitOfWork)
    {
        _innerRouter = innerRouter ?? throw new ArgumentNullException(nameof(innerRouter));
        _memoryCache = memoryCache;
        _unitOfWork = unitOfWork;
    }

    public async Task RouteAsync(RouteContext context)
    {
        I check the routes in the DB using the _unitOfWork   
    }

    public VirtualPathData GetVirtualPath(VirtualPathContext context)
    {
        Also I do the same here...
    }

}

I have no problem with those functions and I'm able to select controller and action.

My problem is how to access the database, since I can't inject the IUnitOfWork dependency into de custom router.

I'm getting this error message:

'Cannot resolve 'IUnitOfWork' from root provider because it requires scoped service 'DbContext'.'

I have my ConfigureServices like this

public void ConfigureServices(IServiceCollection services)
{
    services.AddDbContext<DbContext>(options => options.UseMySQL(configuration.GetConnectionString("DefaultClient")));
    services.AddIdentity<Domain.EntitiesClient.Entities.ApplicationUser, Domain.EntitiesClient.Entities.ApplicationRole>().AddEntityFrameworkStores<DbContext>().AddDefaultTokenProviders();

    services.AddScoped<IDbContext, DbContext>();
    services.AddTransient<IUnitOfWork, UnitOfWork>();

    services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
    services.AddMemoryCache();

    services.AddMvc();

    /*route custom*/
    var supportedCultures = new[] { new CultureInfo("en-US"), new CultureInfo("es-ES"), new CultureInfo("it-IT") };
    var optionsCulture = new RequestLocalizationOptions { DefaultRequestCulture = new RequestCulture("en-US", "en-US"), SupportedCultures = supportedCultures, SupportedUICultures = supportedCultures };

    optionsCulture.RequestCultureProviders = new IRequestCultureProvider[] { new RouteDataRequestCultureProvider() { RouteDataStringKey = "culture", Options = optionsCulture } };
    services.AddSingleton(optionsCulture);

}

And the Configure

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseBrowserLink();
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }

    app.UseStaticFiles();
    app.UseAuthentication();

    app.UseMvc(routes =>
    {
        routes.Routes.Add(new RouteCustom(routes.DefaultHandler
            , routes.ServiceProvider.GetRequiredService<IMemoryCache>()
            , app.ApplicationServices.GetService<IUnitOfWork>()
            ));
        routes.MapRoute(name: "areas", template: "{area:exists}/{controller=Home}/{action=Index}/{id?}");
        routes.MapRoute(name: "default", template: "{controller=Home}/{action=Index}/{id?}");
        });
}

The problem is here

app.ApplicationServices.GetService<IUnitOfWork>()

I need to inject the IUnitOfWork in order to check the database, but I don't know how to do it. In other Middlewares I could inject the IUnitOfWork directly in the function, but in this case I can't do it in the

public async Task RouteAsync(RouteContext context)

How can I achieve this? I'm sure I'm doing something wrong here, but I have been reading a lot of articles and can't figure out the way.

Thanks.

UPDATE: POSSIBLE SOLUTION

The only solution I can think is remove the injection into the IRouter and get the service "manually" inside the RouteAsync method.

public async Task RouteAsync(RouteContext context)
{
    var unitOfWork = context.HttpContext.RequestServices.GetRequiredService<IUnitOfWork>()
    var routes = unitOfWork.Router.GetAll();
    ...
}

This way we have access to the database and it works good. Is it a good approach?

asp.net core custom IRouter Dependency Injection

0 Answers0