Performing Implementations in the Infrastructure Project

Follow these steps to perform implementations in the Infrastructure project:

1. We first add a reference to our Application project from Infrastructure:

2. Then we implement our interfaces, starting with IUoW in the EF folder of the Infrastructure project:

Go to https://goo.gl/SFBMLt to access the code.

using RestBuy.Application.Repos;
using System.Threading;
using System.Threading.Tasks;
namespace RestBuy.Infrastructure.EF
{
  public class RestBuyUoW : IUoW
  {
...
...
  }
}

3. Next, define a BaseRepo that will be the base class for all our repository implementations:

Go to https://goo.gl/s7LVBU to access the code.

using Microsoft.EntityFrameworkCore;
using RestBuy.Application.Repos;
using RestBuy.Application.Services.Queries;
using RestBuy.Entities;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
namespace RestBuy.Infrastructure.EF
{
...
  if (query.Skip > 0)
  {
    filterQuery = filterQuery.Skip(query.Skip);
  }
  if (query.Take > 0)
  {
    filterQuery = filterQuery.Take(query.Take);
  }
  if (query.OrderBy != null || query.OrderByDescending != null)
...
}

The preceding code basically checks if the query has to do with either Take, Skip, or OrderBy clauses, and modifies the query accordingly (depending on these parts of queries defined).

4. Now, define the UserRepo:

Go to https://goo.gl/9wPekN to access the code.

using RestBuy.Application.Repos;
using RestBuy.Entities;
using System.Threading;
using System.Threading.Tasks;
namespace RestBuy.Infrastructure.EF
{
  public class UserRepo : BaseRepo<User> , IUserRepo
  {
    public UserRepo(RestBuyContext restBuyContext) : base(restBuyContext)
    { }
    public Task AddAsync(User user, CancellationToken ct = default) =>
    this.restBuyContext.Users.AddAsync(user, ct);
  }
}

Our EF folder looks as follows:

Finally, we need to define our service interfaces. We will start with user registration. For starters, let's define our ViewModel for registration. We will define the ViewModel directly in the application layer as this will be the input of our service interfaces. Normally in onion layered architecture, we try not to pass data across the layer borders. That's why we are not directly using the entities. One notable exception to this rule is persistence. Since the persistence layer is responsible only for persisting entities, there is no harm passing the entities directly there. Still, this is a hotly debated subject.