Rystem.RepositoryFramework.Abstractions 0.9.8

Interfaces

Based on CQRS we could split our repository pattern in two main interfaces, one for update (write, delete) and one for read.

Command (Write-Delete)

public interface ICommandPattern<T, TKey, TState> : ICommandPattern
    where TKey : notnull
{
    Task<TState> InsertAsync(TKey key, T value, CancellationToken cancellationToken = default);
    Task<TState> UpdateAsync(TKey key, T value, CancellationToken cancellationToken = default);
    Task<TState> DeleteAsync(TKey key, CancellationToken cancellationToken = default);
}

Query (Read)

public interface IQueryPattern<T, TKey, TState> : IQueryPattern
    where TKey : notnull
{
    Task<T?> GetAsync(TKey key, CancellationToken cancellationToken = default);
    Task<TState> ExistAsync(TKey key, CancellationToken cancellationToken = default);
    Task<IEnumerable<T>> QueryAsync(Expression<Func<T, bool>>? predicate = null, int? top = null, int? skip = null, CancellationToken cancellationToken = default);
}

Repository Pattern (Write-Delete-Read)

Repository pattern is a sum of CQRS interfaces.

public interface IRepositoryPattern<T, TKey, TState> : ICommandPattern<T, TKey, TState>, IQueryPattern<T, TKey, TState>, IRepositoryPattern, ICommandPattern, IQueryPattern
    where TKey : notnull
{
}

With bool as TState

Command (Write-Delete)

public interface ICommandPattern<T, TKey> : ICommandPattern<T, TKey, bool>, ICommandPattern
    where TKey : notnull
{
    Task<bool> InsertAsync(TKey key, T value, CancellationToken cancellationToken = default);
    Task<bool> UpdateAsync(TKey key, T value, CancellationToken cancellationToken = default);
    Task<bool> DeleteAsync(TKey key, CancellationToken cancellationToken = default);
}

Query (Read)

public interface IQueryPattern<T, TKey> : IQueryPattern<T, TKey, bool>, IQueryPattern
    where TKey : notnull
{
    Task<T?> GetAsync(TKey key, CancellationToken cancellationToken = default);
    Task<bool> ExistAsync(TKey key, CancellationToken cancellationToken = default);
    Task<IEnumerable<T>> QueryAsync(Expression<Func<T, bool>>? predicate = null, int? top = null, int? skip = null, CancellationToken cancellationToken = default);
}

Repository Pattern (Write-Delete-Read)

Repository pattern is a sum of CQRS interfaces.

public interface IRepositoryPattern<T, TKey> : IRepositoryPattern<T, TKey, bool>, ICommandPattern<T, TKey>, IQueryPattern<T, TKey>, IRepositoryPattern, ICommandPattern, IQueryPattern
    where TKey : notnull
{
}

With bool as TState and string as TKey

Command (Write-Delete)

public interface ICommandPattern<T> : ICommandPattern<T, string>, ICommandPattern
{
    Task<bool> InsertAsync(string key, T value, CancellationToken cancellationToken = default);
    Task<bool> UpdateAsync(string key, T value, CancellationToken cancellationToken = default);
    Task<bool> DeleteAsync(string key, CancellationToken cancellationToken = default);
}

Query (Read)

public interface IQueryPattern<T> : IQueryPattern<T, string>, IQueryPattern
{
    Task<T?> GetAsync(string key, CancellationToken cancellationToken = default);
    Task<bool> ExistAsync(string key, CancellationToken cancellationToken = default);
    Task<IEnumerable<T>> QueryAsync(Expression<Func<T, bool>>? predicate = null, int? top = null, int? skip = null, CancellationToken cancellationToken = default);
}

Repository Pattern (Write-Delete-Read)

Repository pattern is a sum of CQRS interfaces.

public interface IRepositoryPattern<T> : IRepositoryPattern<T, string>, ICommandPattern<T>, IQueryPattern<T>, IRepositoryPattern, ICommandPattern, IQueryPattern
    where TKey : notnull
{
}    

Examples

Model

public class User
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
}

Command

public class UserWriter : ICommandPattern<User, string>
{
    public Task<bool> DeleteAsync(string key, CancellationToken cancellationToken = default)
    {
        //delete on with DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> InsertAsync(string key, User value, CancellationToken cancellationToken = default)
    {
        //insert on DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> UpdateAsync(string key, User value, CancellationToken cancellationToken = default)
    {
        //update on DB or storage context
        throw new NotImplementedException();
    }
}

Query

public class UserReader : IQueryPattern<User, string>
{
    public Task<User?> GetAsync(string key, CancellationToken cancellationToken = default)
    {
        //get an item by key from DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> ExistAsync(string key, CancellationToken cancellationToken = default)
    {
        //check if an item by key exists in DB or storage context
        throw new NotImplementedException();
    }
    public Task<IEnumerable<User>> QueryAsync(Expression<Func<User, bool>>? predicate = null, int? top = null, int? skip = null, CancellationToken cancellationToken = default)
    {
        //get a list of items by a predicate with top and skip from DB or storage context
        throw new NotImplementedException();
    }
}

Alltogether as repository pattern

if you don't have CQRS infrastructure (usually it's correct to use CQRS when you have minimum two infrastructures one for write and delete and at least one for read)

public class UserRepository : IRepositoryPattern<User, string>, IQueryPattern<User, string>, ICommandPattern<User, string>
{
    public Task<bool> DeleteAsync(string key, CancellationToken cancellationToken = default)
    {
        //delete on with DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> InsertAsync(string key, User value, CancellationToken cancellationToken = default)
    {
        //insert on DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> UpdateAsync(string key, User value, CancellationToken cancellationToken = default)
    {
        //update on DB or storage context
        throw new NotImplementedException();
    }
    public Task<User?> GetAsync(string key, CancellationToken cancellationToken = default)
    {
        //get an item by key from DB or storage context
        throw new NotImplementedException();
    }
    public Task<bool> ExistAsync(string key, CancellationToken cancellationToken = default)
    {
        //check if an item by key exists in DB or storage context
        throw new NotImplementedException();
    }
    public Task<IEnumerable<User>> QueryAsync(Expression<Func<User, bool>>? predicate = null, int? top = null, int? skip = null, CancellationToken cancellationToken = default)
    {
        //get a list of items by a predicate with top and skip from DB or storage context
        throw new NotImplementedException();
    }
}

How to use it

In DI you install the service

services.AddRepository<User, string, UserRepository>();

And you may inject the object

IRepository<User, string> repository

Query and Command

In DI you install the services

services.AddCommand<User, string, UserWriter>();
services.AddQuery<User, string, UserReader>();

And you may inject the objects

ICommand<User, string> command
IQuery<User, string> command

Example with default key

In DI you install the services

services.AddRepository<User, UserRepository>();
services.AddCommand<User, UserWriter>();
services.AddQuery<User, UserReader>();

And you may inject the objects

IRepository<User> repository
ICommand<User> command
IQuery<User> command

Example with TState

In DI you install the services, in example we are using a Result class instead the default integration with a return type bool.

services.AddRepository<User, string, Result, UserRepository>();
services.AddCommand<User, string, Result, UserWriter>();
services.AddQuery<User, string, Result, UserReader>();

And you may inject the objects

IRepository<User, string, Result> repository
ICommand<User, string, Result> command
IQuery<User, string, Result> command