Rystem.RepositoryFramework allows you to use correctly concepts like repository pattern, CQRS and DDD. You have interfaces for your domains, auto-generated api, auto-generated HttpClient to simplify connection "api to front-end", a functionality for auto-population in memory of your models, a functionality to simulate exceptions and waiting time from external sources to improve your implementation/business test and load test.
public class User
{
public string Id { get; set; }
public string Name { get; set; }
public string Email { get; set; }
}
Command
Your storage class has to extend ICommand, and use it on injection
public class UserWriter : ICommand<User, string>
{
public Task<IState<User>> DeleteAsync(string key, CancellationToken cancellationToken = default)
{
//delete on with DB or storage context
throw new NotImplementedException();
}
public Task<IState<User>> InsertAsync(string key, User value, CancellationToken cancellationToken = default)
{
//insert on DB or storage context
throw new NotImplementedException();
}
public Task<IState<User>> UpdateAsync(string key, User value, CancellationToken cancellationToken = default)
{
//update on DB or storage context
throw new NotImplementedException();
}
public Task<BatchResults<User, string>> BatchAsync(BatchOperations<User, string> operations, CancellationToken cancellationToken = default)
{
//insert, update or delete some items on DB or storage context
throw new NotImplementedException();
}
}
Query
Your storage class has to extend IQuery, and use it on injection
public class UserReader : IQuery<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<IState<User>> ExistAsync(string key, CancellationToken cancellationToken = default)
{
//check if an item by key exists in DB or storage context
throw new NotImplementedException();
}
public IAsyncEnumerable<IEntity<User, string>> QueryAsync(IFilterExpression filter, CancellationToken cancellationToken = default)
{
//get a list of items by a predicate with top and skip from DB or storage context
throw new NotImplementedException();
}
public ValueTask<TProperty> OperationAsync<TProperty>(OperationType<TProperty> operation, IFilterExpression filter, CancellationToken cancellationToken = default)
{
//get an items count by a predicate with top and skip from DB or storage context or max or min or some other operations
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).
You may choose to extend IRepository, but when you inject you have to use IRepository
public class UserRepository : IRepository<User, string>, IQuery<User, string>, ICommand<User, string>
{
public Task<IState<User>> DeleteAsync(string key, CancellationToken cancellationToken = default)
{
//delete on with DB or storage context
throw new NotImplementedException();
}
public Task<IState<User>> InsertAsync(string key, User value, CancellationToken cancellationToken = default)
{
//insert on DB or storage context
throw new NotImplementedException();
}
public Task<IState<User>> UpdateAsync(string key, User value, CancellationToken cancellationToken = default)
{
//update on DB or storage context
throw new NotImplementedException();
}
public Task<BatchResults<User, string>> BatchAsync(BatchOperations<User, string> operations, CancellationToken cancellationToken = default)
{
//insert, update or delete some items 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<IState<User>> ExistAsync(string key, CancellationToken cancellationToken = default)
{
//check if an item by key exists in DB or storage context
throw new NotImplementedException();
}
public IAsyncEnumerable<IEntity<User, string>> QueryAsync(IFilterExpression filter, CancellationToken cancellationToken = default)
{
//get a list of items by a predicate with top and skip from DB or storage context
throw new NotImplementedException();
}
public ValueTask<TProperty> OperationAsync<TProperty>(OperationType<TProperty> operation, IFilterExpression filter, CancellationToken cancellationToken = default)
{
//get an items count by a predicate with top and skip from DB or storage context or max or min or some other operations
throw new NotImplementedException();
}
}
Twice or more configurations for the same repository service
Pay attention during the DI, you may install the same repository two or more times for the same model. If you want to be sure, you may start the DI with a method that checks for you.
When can it happen? For instance, when you use at the same time InMemory integration with a custom integration.
You can use a class or record.
Record is better in my opinion, for example, if you want to use the Equals operator from key, with record you don't check it by the refence but by the value of the properties in the record.
My key:
public class MyKey
{
public int Id { get; set; }
public int Id2 { get; set; }
}
and you may inject (for ICommand and IQuery is the same)
IRepository<User, MyKey> repository
Default TKey record
You may use the default record key in repository framework namespace.
It's not really useful when used with no-primitive or no-struct objects (in terms of memory usage [Heap]).
For 1 value (it's not really useful I know, but I liked to create it).
new Key<int>(2);
or for 2 values (useful)
new Key<int, int>(2, 4);
or for 3 values (unuseful)
new Key<int, int, string>(2, 4, "312");
or for 4 values (useful)
new Key<int, int, double, Guid>(2, 4, 3, Guid.NewGuid());
or for 5 values (unuseful)
new Key<int, int, string, Guid, string>(2, 4, "312", Guid.NewGuid(), "3232");
and you may inject (for ICommand and IQuery is the same)
IRepository<User, Key<int, int>> repository
Translation
In some cases you need to "translate" your query for your database context query, for example in case of EF integration.
.AddDbContext<SampleContext>(options =>
{
options.UseSqlServer(configuration["ConnectionString:Database"]);
}, ServiceLifetime.Scoped)
.AddRepository<AppUser, AppUserKey, AppUserStorage>()
.Translate<User>()
.With(x => x.Id, x => x.Identificativo)
.With(x => x.Username, x => x.Nome)
.With(x => x.Email, x => x.IndirizzoElettronico)
In this case I'm helping the Filter class to understand how to transform itself when used in a different context.
Use Filter methods to help to translate and apply to your context the right query.
await foreach (var user in filter.ApplyAsAsyncEnumerable(_context.Users))
yield return new AppUser(user.Identificativo, user.Nome, user.IndirizzoElettronico, new());
You may use Filter for queryable, FilterAsEnumerable for Enumerable and FilterAsAsyncEnumerable for async enumerable context.
You can add more translations for the same model
.AddDbContext<SampleContext>(options =>
{
options.UseSqlServer(configuration["ConnectionString:Database"]);
}, ServiceLifetime.Scoped)
.AddRepository<AppUser, AppUserKey, AppUserStorage>()
.Translate<User>()
.With(x => x.Id, x => x.Identificativo)
.With(x => x.Username, x => x.Nome)
.With(x => x.Email, x => x.IndirizzoElettronico)
.AndTranslate<AnotherUser>()
.With(x => x.Id, x => x.Identificativo)
.With(x => x.Username, x => x.Nome)
.With(x => x.Email, x => x.IndirizzoElettronico)
You have the chance to write your business methods to execute them before or after a command or query.
For instance, you have to check before an update or insert the value of an entity and deny the final insert/update on the database.
Example
In this example BeforeInsertAsync runs before InsertAsync of IRepository/ICommand and AfterInsertAsync runs after InsertAsync of IRepository/ICommand.