EzDev.GenericRepository 1.0.0-preview3.1

Easy Generic Repository

EzDev.GenericRepository is a very simplistic, lightweight generic repository based on EntityFramework Core, that doesn't lock you into a certain way of working. You're provided a single base class with simple CRUD-based operations, that you may override if you have other requirements.

Installation

Install with NuGet

or use .NET Core CLI
dotnet add package EzDev.GenericRepository.

Consider using --prelease for preview versions.

How do I get started?

Create a class that inherits from EntityRepository<T> and implement its constructor.
In its simplest form, you can have a repository such as below.

public class SimpleEmployeeRepository : EntityRepository<Employee> {
    public SimpleEmployeeRepository(DbContext context) : base(context) { }
}

That's honestly it.

The SimpleEmployeeRepository now has default implementations for getting, adding, updating, and deleting Employee entities.

More advanced options

Say you have a Company type acting as an aggregate root with a list of employees, and you want to retrieve all employees whenever you query a company.

In this case, you may want to override the default Entities property on the EntityRepository, as demonstrated below.

public class CompanyRepository : EntityRepository<Company> {
    public CompanyRepository(DbContext context) : base(context) {
        Entities = context.Set<Company>().Include(c => c.Employees).AsNoTracking();
    }
}

Extension and listening points

Take advantage of events to plug in your own code without having to override methods. This is great for implementing cross-cutting concerns such as logging.

You can listen to repository events in two ways: implement the methods directly in the repository, or, register them with the dependency injection framework.

public class EmployeeRepositoryWithEvents : EntityRepository<Employee> {
    public EmployeeRepositoryWithEvents(DbContext context, ILogger logger) : base(context) {
        Events = new RepositoryEvents<Employee> {
            OnBeforeSaving = async employee => logger.LogInformation("Before saving employee {Id}", employee.Id),
            OnSaved = async employee => logger.LogInformation("Saved employee {Id}", employee.Id),
            OnSavingFailed = async (employee, exception) => logger.LogError("Saving employee {Id} failed with message {Message}", employee.Id, exception.Message)
        };
    }
}

If you don't want to pollute your repository with logging statements, then you can register the RepositoryEvents<T> with your dependency container framework, such as below.

public class EmployeeRepositoryWithEvents : EntityRepository<Employee> {
    public EmployeeRepositoryWithEvents(DbContext context, RepositoryEvents<Employee> events) :
        base(context, events) { }
}

// In Startup.cs (or elsewhere)
services.AddRepository<Employee, EmployeeTestRepository>()
  .WithEvents<Employee>(_ => {
    OnBeforeSaving = async employee => logger.LogInformation("Before saving employee {Id}", employee.Id),
    OnSaved = async employee => logger.LogInformation("Saved employee {Id}", employee.Id),
    OnSavingFailed = async (employee, exception) => logger.LogError("Saving employee {Id} failed with message {Message}", employee.Id, exception.Message)
  });