Question

I’m wondering where the best place to put Type specific functions is when using a generic repository pattern.

My generic Repository<T> has methods for things like GetMany() etc, but where is the most sensible location to place functions specific to a Type?

A simple example would be, say I have a ‘User’ type and I want a function, which instead of bringing back the firstname / lastname of the user and requiring me to glue them together when the object set is returned, could return FirstName + " " + LastName as ‘Username‘.

The previous non repository pattern implementation I’ve inherited used partial classes on the EF types to provide these extension methods, but I’m a little unsure where to move these type of functions to when using the respository.

Any ideas would be a big help,

Cheers,

Doug

Answer 1

The below link explains how to specify selection, instead of widening the contract of generic repository, the common technique is to subclass the generic repository to implement a specific repository

EF POCO

 public class CustomerRepository : GenericRepository<Customer>, ICustomerRepository
{
    public CustomerRepository(ObjectContext context) : base(context) { }

    public IList<Customer> NewlySubscribed()
    {
        var lastMonth = DateTime.Now.Date.AddMonths(-1);

        return GetQuery().Where(c => c.Inserted >= lastMonth)
        .ToList();
    }

    public Customer FindByName(string firstname, string lastname)
    {
        return GetQuery().Where(c => c.Firstname == firstname && c.Lastname == lastname).FirstOrDefault();
    }
}

you can add your function as the one used for NewlySubscribed()