In an effort to make my entities persistent ignorant and make my repositories testable, I've implemented a repository pattern like so:
public interface IJobRepository : IRepository<Job>
{
Job GetJobById(int jobId); //Special case where I'm eager loading other entities
void SaveJob(Job job, Job originalJob);
}
public class JobRepository : IJobRepository
{
private readonly IContext _context;
public JobRepository()
{
_context = new CustomObjectContext();
}
public JobRepository(UnitOfWork unitOfWork)
{
_context = unitOfWork.Context;
}
//Basic GetAll, GetById, Add and Delete methods from IRepository<T> Interface here
//omitted for brevity
public Job GetJobById(int jobId)
{
var job = _context.Jobs.Include("Company").Include("Location").
Include("PlantInfo").Where(j => j.Jobid == jobId).SingleOrDefault();
_context.DisposeContext();
return job;
}
public void SaveJob(Job job, Job originalJob)
{
if (job.Jobid > 0)
{
// Update
_context.Jobs.Attach(originalJob);
_context.PlantInfoes.Attach(originalJob.PlantInfo);
_context.Jobs.ApplyCurrentValues(job);
_context.PlantInfoes.ApplyCurrentValues(job.PlantInfo);
Note: ApplyCurrentValues is an extension method I'm using on the ObjectSet
}
else
{
// Create
_context.Jobs.AddObject(job);
}
_context.Save();
}
}
public class UnitOfWork
{
private readonly IContext _context;
public UnitOfWork()
{
_context = new CustomObjectContext();
}
public UnitOfWork(IContext context)
{
_context = context;
}
public string Save()
{
return _context.Save();
}
internal IContext Context
{
get { return _context; }
}
}
public interface IContext
{
IObjectSet<Job> Jobs { get; }
IObjectSet<Company> Companies { get; }
IObjectSet<Location> Locations { get; }
IObjectSet<PlantInfo> PlantInfoes { get; }
string Save();
}
My ObjectContext inherits from IContext...So my understanding is that I will only use the overloaded constructor on the repository to facilitate unit tests or to use it in the case that I want to use the same context (not desirable based on this post I found on SO "Entity Framework and Connection Pooling" -- Is this right?
Also, assuming the context only gets disposed when the repository is garbage collected, I have to dispose the context explicitly to avoid the "An entity object cannot be referenced by multiple instances of IEntityChangeTracker." exception when attaching the entity prior to a save.
That said, what is the best practice for managing the DataContext in a manner that keeps your entities persistent ignorant and repositories testable?
Note: This is an asp.net webapplication; UnitOfWork and IContext implementation was based on examples from "Programming Entity Framework", Second Edition by Julia Lerman Ch24.
Thanks in advance!