How can I use an API controller as a service in an ASP.NET Core application? - asp.net-core

Question

I'm new to entity framework and have built a working API with a controller that I'll call APIController. My aim is to use the API as a 'service' in my ASP.NET Core MVC app which is in the same project but a different solution by having an instance of the API controller in my MVC controller and using it for the View requests.
The issue is that doing it this way means I have two contexts: one for the database in the API 'TTContext', which is the main one used to actually edit the files and another in the MVC 'TraineeTrackerContext'which is required for userManager authentication because it needs to inherent IdentityDbContext (which can't be done in the API).
I've tried to introduce these contexts in the program.cs as below:
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using SpartaTraineeTrackerAPI.Models;
using SpartaTraineeTrackerAPI.Service;
using TraineeTrackerMVC.Data;
using SpartaTraineeTrackerAPI.Models;
using SpartaTraineeTrackerAPI.Service;
using TraineeTrackerMVC.Models;
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
builder.Services.AddDbContext<TTContext>(options =>
options.UseSqlServer(connectionString));
builder.Services.AddDbContext<TraineeTrackerContext>(options => options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();
builder.Services.AddDefaultIdentity<User>(options => options.SignIn.RequireConfirmedAccount = true)
.AddEntityFrameworkStores<TTContext>();
builder.Services.AddControllersWithViews();
builder.Services.AddScoped<ITrackerService, TrackerService>();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
app.UseMigrationsEndPoint();
}
else
{
app.UseExceptionHandler("/Home/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.MapRazorPages();
app.Run();
With the idea being that the TraineeTrackerContext has an instance of the TTContext attached like this:
using System;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore;
using TraineeTrackerMVC.Models;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using SpartaTraineeTrackerAPI.Models;
namespace TraineeTrackerMVC.Data;
public partial class TraineeTrackerContext : IdentityDbContext
{
public TraineeTrackerContext()
{
ttContext = new TTContext();
}
public TraineeTrackerContext(TTContext context)
{
ttContext = context;
}
/*
public TraineeTrackerContext(DbContextOptions<TraineeTrackerContext> options)
: base(options)
{
ttContext = new TTContext(options);
}
*/
public TTContext ttContext;
public virtual DbSet<Profile> Profiles { get; set; }
public virtual DbSet<Tracker> Trackers { get; set; }
public virtual DbSet<User> Users { get; set; }
public TraineeTrackerContext(DbSet<Tracker> trackers, DbSet<User> users, DbSet<Profile> profiles)
{
Trackers = trackers;
Users = users;
Profiles = profiles;
}
}
But running it throws two exceptions when doing builder.Build():
InvalidOperationException: Error while validating the service descriptor ServiceType
System.AggregateException: Unable to activate type Trainee TrackerContext
I've been trying to fix these myself but I'm very new to Entity Framework and this is one of the first applications I've made so I was hoping someone could help explain where I'm going wrong and perhaps how to do this correctly. I haven't found many resources online using the API as a service in this way, as others tend to use the HttpClient class. Any help would be appreciated.