ReadonlyDbContextGenerator 0.0.1

ReadOnly DbContext Source Generator

Overview

The ReadOnlyDbContextGenerator is a C# source generator that creates read-only versions of EF Core DbContext and entities. It ensures that the generated DbContext and entities prevent modifications, making them suitable for read-only operations in applications.

How It Works

1. DbContext Analysis

   • Identifies classes inheriting from Microsoft.EntityFrameworkCore.DbContext.
   • Extracts the DbSet properties and their entity types.

2. Entity Processing

   • Analyzes the entity types referenced in the DbSet properties.
   • Converts their properties to init-only.
   • Modifies navigation properties to reference read-only entities or collections.

3. Entity Configuration

   • Identifies and processes IEntityTypeConfiguration implementations.
   • Generates read-only configuration classes for the entities.

4. Code Generation

   • Produces source files for:
     • Read-only DbContext.
     • Read-only entity classes.
     • Entity configuration classes.
     • IReadOnlyDbContext interface.

Usage

1. Add the source generator to your project:

   dotnet add package ReadOnlyEfCoreGenerator
   

2. Build your project. The generator will create source files for the read-only components.

3. Access the generated read-only DbContext and entities:

   var readOnlyDbContext = new ReadOnlyMyDbContext();
   

Example

Input

DbContext

public class MyDbContext : DbContext
{
    public DbSet<User> Users { get; set; }
    public DbSet<Order> Orders { get; set; }
}

Entity

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Order> Orders { get; set; }
}

public class Order
{
    public int Id { get; set; }
    public string Product { get; set; }
    public User User { get; set; }
}

Generated Output

ReadOnlyMyDbContext

public class ReadOnlyMyDbContext : IReadOnlyMyDbContext
{
    public IReadOnlyCollection<User> Users { get; }
    public IReadOnlyCollection<Order> Orders { get; }

    public int SaveChanges()
    {
        throw new NotImplementedException("Read-only context");
    }
}

ReadOnlyUser

public class ReadOnlyUser
{
    public int Id { get; init; }
    public string Name { get; init; }
    public IReadOnlyCollection<ReadOnlyOrder> Orders { get; init; }
}

ReadOnlyOrder

public class ReadOnlyOrder
{
    public int Id { get; init; }
    public string Product { get; init; }
    public ReadOnlyUser User { get; init; }
}

IReadOnlyMyDbContext

public interface IReadOnlyMyDbContext : IDisposable, IAsyncDisposable
{
    IReadOnlyCollection<ReadOnlyUser> Users { get; }
    IReadOnlyCollection<ReadOnlyOrder> Orders { get; }
}