It's a week I have been dealing with Repository pattern, somehow I have implemented something, a generic repository:
private CentralEntities db = null;
private DbSet<T> table = null;
public RepositoryTest()
{
this.db = new CentralEntities();
table = db.Set<T>();
}
public RepositoryTest(CentralEntities db)
{
this.db = db;
table = db.Set<T>();
}
public IEnumerable<T> SelectAll()
{
return table.Take(10).ToList();
}
Here is my IRepository:
public interface IRepositoryTest<T> where T:class
{
IEnumerable<T> SelectAll();
}
Here in my Controller I implemented like the following and it works:
public class DashbrdController : Controller
{
IRepositoryTest<Event> _repository = null;
public DashbrdController(IRepositoryTest<Event> _repository)
{
this._repository = _repository;
}
public DashbrdController()
{
this._repository = new RepositoryTest<Event>();
}
public ActionResult DashBrd()
{
var rslt= _repository.SelectAll().Take(10);
return View(rslt);
}
}
First I do not how to implement Iunitofwork and UnitOfWork, and second apart from creating a single gate for update or insert, whats the usage of UnitOfWork? what kind of problem can it solve in the above example?
Please refer to the section below for detail understanding of UOW and Repository:
1) You create Generic Repository (The base of all the data source):
public class GenericRepository : IGenericRepository where T :
class
{
protected DbContext _entities;
protected readonly IDbSet<T> _dbset;
public GenericRepository(DbContext context)
{
_entities = context;
_dbset = context.Set<T>();
}
public IEnumerable<T> GetAll()
{
return _dbset.AsEnumerable();
}
public IEnumerable<T> FindBy(System.Linq.Expressions.Expression<Func<T, bool>> predicate)
{
IEnumerable<T> query = _dbset.Where(predicate).AsEnumerable();
return query;
}
public virtual T GetSingle(System.Linq.Expressions.Expression<Func<T, bool>> predicate)
{
T query = _dbset.Where(predicate).FirstOrDefault();
return query;
}
public virtual void Add(T entity)
{
_dbset.Add(entity);
}
public virtual void Delete(T entity)
{
_dbset.Remove(entity);
}
public virtual void Edit(T entity)
{
_entities.Entry(entity).State = EntityState.Modified;
}
public virtual void Attach(T entity)
{
_dbset.Attach(entity);
}
public virtual void Save()
{
_entities.SaveChanges();
}
}
2) Then you create a Unit Of Work (Generic that adds the instance of Repository)
public sealed class GenericUnitOfWork : IGenericUnitOfWork, IDisposable
{
private ApplicationDbContext entities = null;
private ApplicationUserManager _userManager;
public GenericUnitOfWork()
{
entities = new ApplicationDbContext();
}
public Dictionary<Type, object> repositories = new Dictionary<Type, object>();
public IGenericRepository<T> Repository<T>() where T : class
{
if (repositories.Keys.Contains(typeof(T)) == true)
{
return repositories[typeof(T)] as IGenericRepository<T>;
}
IGenericRepository<T> repo = new GenericRepository<T>(entities);
repositories.Add(typeof(T), repo);
return repo;
}
public int Commit()
{
return entities.SaveChanges();
}
private bool disposed = false;
private void Dispose(bool disposing)
{
if (!this.disposed)
{
if (disposing)
{
entities.Dispose();
}
}
this.disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
3) Then you call UnitOfWork from your controller, that creates instance of Repository in Generic Form
public class DashbrdController : Controller
{
private GenericUnitOfWork uow = null;
public DashbrdController()
{
uow = new GenericUnitOfWork();
}
public ActionResult DashBrd()
{
var rslt = uow.Repository<Event>().GetAll().ToList();
return View(rslt);
}
}
The unit of work class coordinates the work of multiple repositories by creating a single database context class shared by all of them.
For a specific user action (say adding a event), all the transactions like insert/update/delete and so on are done in one single transaction, rather then doing multiple database transactions. This means, one unit of work here involves insert/update/delete operations, all in one single transaction.
Please make the interfaces with the implementation classes provided above. Let me know if problem occurs in that.
Hope if helps.
Related
I am wondering, how we can handle a situation, and if I'm going about this the wrong way. We wrote a web application based on one ERP's database schema model. We are using Entity Framework for the system, with the regular dependency injection method.
Now that we have purchased multiple ERP's from other labs, we are trying to allow their data be used on our first original web portal built for our original ERP. As you can imagine, this is rough as the database models and design will not line up with ours. For example something like GetAllAssets() stored procedure returns the complex type and then is bound to the repo level, the service level and onto the view.
What I was thinking is that we could maybe add multiple EDMX (context for databases), then keep everything from the Views to the controllers to the service layer the same. At the service layer, and type params to our classes, and so we could pass the context the current user logged in as, and then in auto mapper add new entries for the new database context calls from Entity Framework, to map to our original code from the service back down to the view.
Is this possible, and or a good idea or bad idea?
Here is a example of a current basic controller we are using with DI style, and I have removed a lot of code for this question's example:
[AuthorizeWithSession]
public class LocationController : Controller
{
private readonly IMProAssetLocationService _mProAssetLocationService;
private readonly IUIDataService _uiDataService;
public LocationController(IMProAssetLocationService mProAssetLocationService,
IUIDataService uiDataService)
{
_mProAssetLocationService = mProAssetLocationService;
}
public ActionResult List()
{
return View();
}
public ActionResult List2()
{
return View();
}
public ActionResult GetLocationList([DataSourceRequest]DataSourceRequest request)
{
//var result = DepartmentService.GetDepartmentList(SessionHelper.GetCustId());
var result = _mProAssetLocationService.MProAssetLocationGetLocationByCustID(SessionHelper.GetCustId(), null);
if (result != null && result.Any())
{
return Json(result.ToDataSourceResult(request), JsonRequestBehavior.AllowGet);
}
}
}
The interface service layer:
public interface IMProAssetLocationService
{
IEnumerable<LocationVm> MProAssetLocationGetLocationByCustID(string custId,string id);
string MProAssetLocationInsertLocation(LocationVm vm);
void MProAssetLocationDeleteLocationByCustIDAndLocationID(string custId, string locationId);
void MProAssetLocationUpdateLocationByCustIDAndLocationID(LocationVm vm);
}
The service layer:
public class MProAssetLocationService : LogManager, IMProAssetLocationService
{
private readonly IMProAssetLocationRepo _mProAssetLocationRepo;
public MProAssetLocationService(IMProAssetLocationRepo mProAssetLocationRepo)
{
_mProAssetLocationRepo = mProAssetLocationRepo;
}
protected override Type LogPrefix
{
get { return this.GetType(); }
}
public IEnumerable<LocationVm> MProAssetLocationGetLocationByCustID(string custId, string id)
{
List<LocationVm> listlocationVm = new List<LocationVm>();
try
{
var records = _mProAssetLocationRepo.MProAssetLocationGetLocationByCustID(custId,id);
}
}
The Interface repo layer:
public interface IMProAssetLocationRepo : IRepository<MProAssetLocation>
{
IEnumerable<string> GetMProAssetLocatonByCustId(string custId);
IEnumerable<string> GetMProAssetLocatonDescriptionByCustId(string custId);
IEnumerable<LocationView> GetMProAssetLocatonListByCustId(string search, string locationID, string custId);
IEnumerable<LocationView> MProAssetLocationGetLocationByCustID(string custId, string id);
string MProAssetLocationInsertLocation(LocationView lv);
void MProAssetLocationDeleteLocationByCustIDAndLocationID(string custId, string locationId);
void MProAssetLocationUpdateLocationByCustIDAndLoacationID(LocationView lv);
}
The repo layer:
public class CalLocationsRepo : RepositoryBase<CalLocaton>, ICalLocationsRepo
{
public CalLocationsRepo(IDbFactory dbFactory)
: base(dbFactory)
{
}
//WHERE CalCodeActive=1 AND CalCodeGroup='OSS' ORDER BY CalCode
public IEnumerable<string> GetCalLocations(string empID)
{
return DbContext.TAM_GetCalLocationsList(empID).ToList();
}
}
I was thinking of something like using a context type in our system. I know the entity models calls would be named differently based on our different databases using their own stored procedures, but thought at the level prior to the call i check the context to use, then make the call accordingly like so:
public class DBContextRepo<T> : RepositoryBase, IDBContextRepo<T>
{
DBContextRepo<T> _typeParameterClass;
public DBContextRepo(IDbFactory dbFactory, DBContextRepo<T> typeParameterClass)
: base(dbFactory)
{
_typeParameterClass = typeParameterClass;
}
public List<string> GetAllModelsByManufcaturer(string manufacturerName)
{
List<string> results = new List<string>();
if (_typeParameterClass.GetType() == typeof(TAM.DataLayer.EntityModels.QuoteWerks1Entities))
{
using(var dbContext = DbContextQw)
{
var items = dbContext.Products_OurProducts_Products.Where(p => p.Manufacturer == manufacturerName).ToList();
results = items.Select(p => p.ManufacturerPartNumber).ToList();
}
}
else
{
using (var dbContext = DbContext)
{
var items = dbContext.Models.Where(a => a.Manufacturer.MfrName == manufacturerName);
results = items.Select(m => m.ModelNumber).ToList();
}
}
return results;
}
}
This causes errors and is where im not sure how to handle two DBContext:
public class DbFactory : Disposable, IDbFactory
{
private TAMModel _dbContext;
private QuoteWerks1Entities _dbContextQW;
public TAMModel Init()
{
return _dbContext ?? (_dbContext = new TAMModel());
}
public QuoteWerks1Entities InitQW()
{
return _dbContextQW ?? (_dbContextQW = new QuoteWerks1Entities());
}
protected override void DisposeCore()
{
if (_dbContext != null)
{
_dbContext.Dispose();
}
if (_dbContextQW != null)
{
_dbContextQW.Dispose();
}
}
}
Once i added the second context, all of my regular code say they do not have a corresponding type in constructors such as this one:
public class ContractRepo : RepositoryBase<Contract>, IContractRepo
{
public ContractRepo(IDbFactory dbFactory)
: base(dbFactory)
{
}
public string GetContractIdentifyByCustId(string custId)
{
return DbContext.TAM_GetContractIdentifyByCustId(custId).SingleOrDefault();
}
}
Here is the BaseRepo class:
public class RepositoryBase
{
private readonly TAMModel _dataContext;
private readonly QuoteWerks1Entities _dataContextQW;
protected IDbFactory DbFactory { get; private set; }
protected TAMModel DbContext
{
get
{
return _dataContext ?? DbFactory.Init();
}
}
protected QuoteWerks1Entities DbContextQw
{
get
{
return _dataContextQW ?? DbFactory.InitQW();
}
}
protected RepositoryBase(IDbFactory dbFactory)
{
DbFactory = dbFactory;
}
}
public abstract class RepositoryBase<T> where T : class
{
private readonly TAMModel _dataContext;
private readonly IDbSet<T> _dbSet;
private readonly IDbSet<T> _dbSetQW;
private readonly QuoteWerks1Entities _dataContextQW;
protected IDbFactory DbFactory { get; private set; }
protected TAMModel DbContext
{
get
{
return _dataContext ?? DbFactory.Init();
}
}
protected QuoteWerks1Entities DbContextQW
{
get
{
return _dataContextQW ?? DbFactory.InitQW();
}
}
protected RepositoryBase(IDbFactory dbFactory, T type)
{
DbFactory = dbFactory;
_dbSet = DbContext.Set<T>();
_dbSetQW = DbContextQW.Set<T>();
}
public virtual void Add(T entity)
{
_dbSet.Add(entity);
}
public virtual void Update(T entity)
{
_dbSet.Attach(entity);
DbContext.Entry(entity).State = EntityState.Modified;
}
public virtual void Delete(T entity)
{
_dbSet.Remove(entity);
}
public virtual void Delete(Expression<Func<T, bool>> where)
{
IEnumerable<T> objects = _dbSet.Where<T>(where);
foreach (T obj in objects)
{
_dbSet.Remove(obj);
}
}
public virtual T GetById(int id)
{
return _dbSet.Find(id);
}
public virtual T GetById(string id)
{
return _dbSet.Find(id);
}
public virtual IEnumerable<T> GetAll()
{
return _dbSet.ToList();
}
public virtual IEnumerable<T> GetMany(Expression<Func<T, bool>> where)
{
return _dbSet.Where(where).ToList();
}
public T Get(Expression<Func<T, bool>> where)
{
return _dbSet.Where(where).SingleOrDefault();
}
public virtual IQueryable<T> Query()
{
return _dbSet;
}
public virtual IQueryable<T> Query(Expression<Func<T, bool>> where)
{
return _dbSet.Where(where);
}
public virtual ObjectQuery<U> CreateQuery<U>(string query, ObjectParameter[] parameters)
{
return CastAsObjectContext().CreateQuery<U>(query, parameters);
}
public virtual ObjectQuery<U> CreateQuery<U>(string query)
{
return CreateQuery<U>(query, new ObjectParameter[0] { });
}
public virtual ObjectQuery<DbDataRecord> CreateQuery(string query, ObjectParameter[] parameters)
{
return CreateQuery<DbDataRecord>(query, parameters);
}
public virtual ObjectQuery<DbDataRecord> CreateQuery(string query)
{
return CreateQuery<DbDataRecord>(query);
}
private ObjectContext CastAsObjectContext()
{
var oContext = (DbContext as IObjectContextAdapter).ObjectContext;
return oContext;
}
}
The only problem is, how do I set the context on a login when using dependency injection? Will this work, as at the moment I'm still in the process, or am I over complicating it and going about it the wrong way? Thanks in advance.
I am trying to create a Repository & UnitOfWork for Data Access Layer. In my current implementation I have to modify my UnitOfWork everytime I create a new repository. I would like to avoid that and also keep the functionality to extend my repository abstract class.
Following is my generic Repository & UnitOfWork interface & classes
public interface IRepositoryBase<T> where T : class
{
IList<T> FindAll();
T FindByCondition(Expression<Func<T, bool>> expression);
void Create(T entity);
void Update(T entity);
void Delete(T entity);
}
public abstract class RepositoryBase<T> : IRepositoryBase<T> where T : class
{
protected DBContext _dbContext { get; set; }
public RepositoryBase(DBContext dbContext)
{
_dbContext = dbContext;
}
//other methods removed
public void Create(T entity)
{
_dbContext.Set<T>().Add(entity);
}
}
public interface IUnitOfWork
{
IReminderRepository Reminder { get; }
void Save();
}
public class UnitOfWork : IUnitOfWork, IDisposable
{
protected DBContext _dbContext { get; set; }
private IReminderRepository _reminderRepository;
public UnitOfWork(DBContext dbContext)
{
_dbContext = dbContext;
}
public IReminderRepository Reminder
{
get
{
return _reminderRepository = _reminderRepository ?? new ReminderRepository(_dbContext);
}
}
public void Save()
{
_dbContext.SaveChanges();
}
public void Dispose()
{
_dbContext.Dispose();
}
}
Here I can extend my Repository as per my specific needs by implementing the specific Repository as
public interface IReminderRepository : IRepositoryBase<Reminder>
{
IList<Reminder> GetAllReminders();
Reminder GetReminderById(Guid id);
Reminder GetReminderByName(string name);
void CreateReminder(Reminder reminder);
void UpdateReminder(Reminder reminder);
void DeleteReminder(Reminder reminder);
}
public class ReminderRepository : RepositoryBase<Reminder>, IReminderRepository
{
public ReminderRepository(DBContext dbContext)
: base(dbContext)
{
_dbContext = dbContext;
}
//other methods removed
public Reminder GetReminderByName(string name)
{
return FindAll()
.OrderByDescending(r => r.Name)
.FirstOrDefault(r => r.Name == name);
//return FindByCondition(r => r.Name == name);
}
}
This is ok but when ever I will create a new Specific Repository I will have to modify the UnitOfWork class as well by adding a new property for the new Repository.
While searching online I found following but it does not work in my case as my RepositoryBase is an abstract class.
public interface IUnitOfWork
{
void Save();
}
public class UnitOfWork : IUnitOfWork, IDisposable
{
private readonly DBContext _dbContext { get; set; }
private readonly Dictionary<Type, object> _repositories = new Dictionary<Type, object>();
public Dictionary<Type, object> Repositories
{
get { return _repositories; }
set { Repositories = value; }
}
public UnitOfWork(DBContext dbContext)
{
_dbContext = dbContext;
}
public IRepositoryBase<T> Repository<T>() where T : class
{
if (Repositories.Keys.Contains(typeof(T)))
{
return Repositories[typeof(T)] as IRepositoryBase<T>;
}
IRepositoryBase<T> repo = new RepositoryBase<T>(_dbContext);//This does not work
Repositories.Add(typeof(T), repo);
return repo;
}
public void Save()
{
_dbContext.SaveChanges();
}
}
You obviously need to get a reference to a IReminderRepository somewhere in your code to be able to use the remainder specific APIs.
If you don't want to extend your UnitOfWork class to return an IReminderRepository, you may create one yourself in the method that actually uses the specific repository, e.g.:
using (var context = new DBContext())
{
IUnitOfWork uow = new UnitOfWork(context);
ReminderRepository repository = new ReminderRepository(context);
Reminder remainder = repository.GetReminderByName("...");
remainder.SomeProperty = "updated value..";
uow.Save();
}
The only purpose of using the unit of work is to be able to share the same context between several different repositories anyway. Exposing a Dictionary<Type, object> in your UnitOfWork won't solve anything as the purpose of using generics is to provide compile-time type safety.
I am working on crud operations in mvc 4.0 with unitofwork and generic repository with Ninject for DI.
I am able to get a particular record from a table, I am even able to get all the records from the table.
but I am not able to insert a new record in the database table. I am not getting any error/exception and it is running each statement
cleanly but there is no effect in database below is my controller where I am using the repository and unitof work.
Can somebody tell me where I am wron or what code/statements I have left in this code. I ahve checked it lot of time and I am stucked now.
Not getting the problem
Controller:
private IUnitOfWork _unitOfWork;
private IRepository<tbl_Employee> _Repo;
private IRepository<tbl_Department> _Department;
public HomeController( IUnitOfWork UOW, IRepository<tbl_Employee> Repository, IRepository<tbl_Department> Depart)
{
this._unitOfWork = UOW;
this._Repo = Repository;
this._Department = Depart;
}
//This runs successfully and gets all the records in the view page and I am displaying all records using foreach in div structure
public ActionResult Index()
{
EmployeeModel ObjModel = new EmployeeModel();
ObjModel.Employees = this._Repo.GetALL();
//ObjModel.Employees = this._Employee.GetEmployees();
return View(ObjModel);
}
//This also runs successfully and it brought me a single record on selection of particular record from employee listing.
public ActionResult EmployeeDetail(string id)
{
EmployeeDetailModel ObjModel = new EmployeeDetailModel();
if (!string.IsNullOrEmpty(id))
{
var Employee = this._Repo.Find(Convert.ToInt32(id));
if (Employee != null)
{
ObjModel.InjectFrom(Employee);
}
}
return View(ObjModel);
}
// Here is the problem . Not able to insert the record. The model object is not empty . I have checked it and there is no error.It brought me a message
"Employee Created Successfully but in database there is no record.
public ActionResult SaveEmployee(EmployeeDetailModel Model)
{
string Msg = string.Empty;
try
{
tbl_Employee ObjEmployee = new tbl_Employee();
ObjEmployee.InjectFrom(Model);
if (Model.Male)
{
ObjEmployee.Sex = "m";
}
else
{
ObjEmployee.Sex = "f";
}
ObjEmployee.Department_Id = Model.Dept_id;
ObjEmployee.Salary = Convert.ToInt32(Model.Salary);
this._Repo.Insert(ObjEmployee);
this._unitOfWork.Commit();
Msg = "Employee Created Successfully";
}
catch
{
Msg = "Error occurred while creating the employee, Please try again.";
}
return Json(new { Message = Msg });
}
/// Repository interface
public interface IRepository<T> where T : class
{
void Insert(T entity);
void Delete(T entity);
void Update(T entity);
T Find(int key);
IEnumerable<T> GetALL();
}
Repository class
public class Repository<T> : Connection, IRepository<T> where T : class
{
private readonly DbSet<T> _dbSet;
public Repository()
{
_dbSet = _dbContext.Set<T>();
}
public void Insert(T entity)
{
_dbSet.Add(entity);
}
public void Delete(T entity)
{
_dbSet.Remove(entity);
}
public void Update(T entity)
{
var updated = _dbSet.Attach(entity);
_dbContext.Entry(entity).State = EntityState.Modified;
//_dataContext.Entry(item).State = EntityState.Modified;
}
public T Find(int Key)
{
var dbResult = _dbSet.Find(Key);
return dbResult;
}
public IEnumerable<T> GetALL()
{
return _dbSet;
}
}
UnitofWork Interface
public interface IUnitOfWork : IDisposable
{
void Commit();
}
Unit of work class
public class UnitOfWork : Connection, IUnitOfWork
{
private bool _disposed;
public void Commit()
{
_dbContext.SaveChanges();
}
public void Dispose()
{
Dispose(true);
// Take yourself off the Finalization queue to prevent finalization code for object from executing a second time.
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
// Check to see if Dispose has already been called.
if (!_disposed)
{
// If disposing equals true, dispose all managed and unmanaged resources.
if (disposing)
{
// Dispose managed resources.
if (_dbContext != null)
{
_dbContext.Dispose();
}
}
}
_disposed = true;
}
}
My UnitofWork and Repository class derives from connection class where dbcontext is defined.
public abstract class Connection
{
protected db_TestEntities _dbContext;
public Connection()
{
this._dbContext = new db_TestEntities();
}
}
Is it that my dbContext is creating a new instance everytime like explained Here
and if yes then how can I resolve it.
tbl_Employee ObjEmployee = new tbl_Employee();
ObjEmployee.InjectFrom(Model);
if (Model.Male)
{
ObjEmployee.Sex = "m";
}
else
{
ObjEmployee.Sex = "f";
}
ObjEmployee.Department_Id = Model.Dept_id;
ObjEmployee.Salary = Convert.ToInt32(Model.Salary);
this._Repo.Insert(ObjEmployee);
After this, you should see your object mapped by EF in local memory.
this._unitOfWork.Commit();
Here your object should be pushed to database. dbContext.SaveChanges() return number of changed records which should be in your case 1.
Msg = "Employee Created Successfully";
Update:
So the problem is in your Connection class as you suggested.
I would create your DbContext in one place and then pass it to repository and unit of work. You could also create DbContext in unit of work constructor and then pass UOW to repository. This is one of my older implementation of this:
public class EntityFrameworkUnitOfWork : IUnitOfWork
{
private ForexDbContext dbContext;
internal ForexDbContext DbContext
{
get { return dbContext ?? (dbContext = new ForexDbContext()); }
}
internal DbSet<T> Set<T>()
where T : class
{
return DbContext.Set<T>();
}
public void Dispose()
{
if(dbContext == null) return;
dbContext.Dispose();
dbContext = null;
}
public void SaveChanges()
{
int result = DbContext.SaveChanges();
}
public ITransaction BeginTransaction()
{
return new EntityFrameworkTransaction(DbContext.BeginTransaction());
}
}
public class ContactsRepositoryWithUow : IRepository<Contact>
{
private SampleDbEntities entities = null;
public ContactsRepositoryWithUow(SampleDbEntities _entities)
{
entities = _entities;
}
public IEnumerable<Contact> GetAll(Func<Contact, bool> predicate = null)
{
if (predicate != null)
{
if (predicate != null)
{
return entities.Contacts.Where(predicate);
}
}
return entities.Contacts;
}
public Contact Get(Func<Contact, bool> predicate)
{
return entities.Contacts.FirstOrDefault(predicate);
}
public void Add(Contact entity)
{
entities.Contacts.AddObject(entity);
}
public void Attach(Contact entity)
{
entities.Contacts.Attach(entity);
entities.ObjectStateManager.ChangeObjectState(entity, EntityState.Modified);
}
public void Delete(Contact entity)
{
entities.Contacts.DeleteObject(entity);
}
}
Please find answer in below link for more details
Crud Operation with UnitOfWork
Following is my code. I want to know it is true or not.
public interface IRepository<T> : IDisposable
{
IQueryable<T> GetAll();
T Update(T entity);
T Insert(T entity);
T GetById(T entity);
void Delete(T entity);
void Save();
}
public class Repository<T> : IRepository<T> where T : class
{
private readonly SchoolDBEntities _context;
public Repository(SchoolDBEntities context)
{
_context = context;
}
public IQueryable<T> GetAll()
{
return _context.Set<T>();
}
public T Update(T entity)
{
var result = _context.Set<T>().Attach(entity);
_context.Entry(entity).State = EntityState.Modified;
return result;
}
public T Insert(T entity)
{
return _context.Set<T>().Add(entity);
}
public T GetById(T entity)
{
return _context.Set<T>().Find(entity);
}
public void Delete(T entity)
{
_context.Set<T>().Remove(entity);
}
public void Save()
{
_context.SaveChanges();
}
public void Dispose()
{
_context.Dispose();
}
}
The problem is, I don't know when and where to call the Save and Dispose methods.
Don't do dispose in IRepository<T>
Try UnitOfWork pattern like this
public interface IUnitOfWork : IDisposable
{
IRepository<Cart> CartRepository { get; }
IRepository<Product> ProductRepository { get; }
void Save();
}
public class UnitOfWork : IUnitOfWork
{
readonly SqlDbContext _context;
public UnitOfWork()
{
_context = new SqlDbContext();
}
private bool _disposed;
protected virtual void Dispose(bool disposing)
{
if (!_disposed)
{
if (disposing)
{
_context.Dispose();
}
}
_disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
public void Save()
{
_context.SaveChanges();
}
public IGenericRepository<Cart> CartRepository
{
get { return new Repository<Cart>(_context); }
}
public IGenericRepository<User> UserRepository
{
get { return new Repository<User>(_context); }
}
}
You can call it like this
using (_unitOfWork)
{
var p = _unitOfWork.ProductRepository.SingleOrDefault(p => p.Id == productId);
_cartRepository.Add(p);
_unitOfWork.Save();
}
I think it depends on the way you use this repo.
So save when you want to save and dispose when you want to finish your work ... on application close etc..
As you use a Unit of Work pattern here, obviously you should call Save method if user (of a repository) send save changes command. It could be a person clicking Apply changes button on one of your Edit forms or other part of your application which handles some transaction logic and saves/discards changes based on it. So basically, when the logical set of changes is ready to be save, Repository takes care of it.
Hi I am using Unity to manage my service layers, which in turn speak to UnitOfWork which manages all the repositories.
Some of my services call other services, my question is how can i pass the same UnitOfWork between service layers?
In my case all controller actions are initiated from a GUI on each button action or event on a timer, this is why I have a factory to create UnitOfWork on demand, but it is causing issues as i dont know how to pass this UnitOfWork between services.
Especially difficult is knowing how to get this specific UnitOfWork instance injected into the service constructor. Please note that some of the services may be long running (10 minutes or so on a background thread), i don't know if that has any impact on the design or not.
Currently the service that is called from the other service is then creating its own UnitOfWork which is causing issues for both transactional design, and Entity framework entity tracking.
Suggestions very welcome!
class OtherService : IOtherService
{
public OtherService(IUnitOfWorkFactory unitOfworkFactory,
ISettingsService settingsService)
{
UnitOfWorkFactory = unitOfworkFactory;
SettingsService = settingsService;
}
IUnitOfWorkFactory UnitOfWorkFactory;
ISettingsService SettingsService;
function SomeSeviceCall()
{
// Perhaps one way is to use a factory to instantiate a
// SettingService, and pass in the UnitOfWork here?
// Ideally it would be nice for Unity to handle all of
// the details regardless of a service being called from
// another service or called directly from a controller
// ISettingsService settingsService =
// UnityContainer.Resolve<ISettingService>();
using (var uow = UnitOfWorkFactory.CreateUnitOfWork())
{
var companies = uow.CompaniesRepository.GetAll();
foreach(Company company in companies)
{
settingsService.SaveSettings(company, "value");
company.Processed = DateTime.UtcNow();
}
uow.Save();
}
}
}
class SettingsService : ISettingsService
{
public SettingsService(IUnitOfWorkFactory unitOfworkFactory)
{
UnitOfWorkFactory = unitOfworkFactory;
}
IUnitOfWorkFactory UnitOfWorkFactory;
// ISettingsService.SaveSettings code in another module...
function void ISettingsService.SaveSettings(Company company,
string value)
{
// this is causing an issue as it essentially creates a
// sub-transaction with the new UnitOfWork creating a new
// Entiy Framework context
using (var uow = UnitOfWorkFactory.CreateUnitOfWork())
{
Setting setting = new Setting();
setting.CompanyID = company.CompanyID;
setting.SettingValue = value;
uow.Insert(setting);
uow.Save();
}
}
}
Hi I've been battling with this problem this is what I've come up with...
public class UnitOfWorkFactory
{
private static readonly Hashtable _threads = new Hashtable();
private const string HTTPCONTEXTKEY =
"AboutDbContext.UnitOfWorkFactory";
public static IUnitOfWork Create()
{
IUnitOfWork unitOfWork = GetUnitOfWork();
if (unitOfWork == null || unitOfWork.IsDisposed)
{
unitOfWork = new UnitOfWork();
SaveUnitOfWork(unitOfWork);
}
return unitOfWork;
}
public static IUnitOfWork GetUnitOfWork()
{
if (HttpContext.Current != null)
{
if (HttpContext.Current.Items.Contains(HTTPCONTEXTKEY))
{
return (IUnitOfWork)HttpContext
.Current.Items[HTTPCONTEXTKEY];
}
return null;
}
var thread = Thread.CurrentThread;
if (string.IsNullOrEmpty(thread.Name))
{
thread.Name = Guid.NewGuid().ToString();
return null;
}
lock (_threads.SyncRoot)
{
return (IUnitOfWork)_threads[Thread.CurrentThread.Name];
}
}
private static void SaveUnitOfWork(IUnitOfWork unitOfWork)
{
if (HttpContext.Current != null)
{
HttpContext.Current.Items[HTTPCONTEXTKEY] = unitOfWork;
}
else
{
lock (_threads.SyncRoot)
{
_threads[Thread.CurrentThread.Name] = unitOfWork;
}
}
}
public static void DisposeUnitOfWork(IUnitOfWork unitOfWork)
{
if (HttpContext.Current != null)
{
HttpContext.Current.Items.Remove(HTTPCONTEXTKEY);
}
else
{
lock (_threads.SyncRoot)
{
_threads.Remove(Thread.CurrentThread.Name);
}
}
}
}
public interface IUnitOfWork : IDisposable
{
void Commit();
bool IsDisposed { get; }
}
public class UnitOfWork : MyContext
{
}
public abstract class Repository<T>
: IRepository<T>, IDisposable where T : class
{
private UnitOfWork _context;
private UnitOfWork Context
{
get
{
if (_context == null || _context.IsDisposed)
return _context = GetCurrentUnitOfWork<UnitOfWork>();
return _context;
}
}
public TUnitOfWork GetCurrentUnitOfWork<TUnitOfWork>()
where TUnitOfWork : IUnitOfWork
{
return (TUnitOfWork)UnitOfWorkFactory.GetUnitOfWork();
}
public IEnumerable<T> Get(Expression<Func<T, bool>> predicate)
{
return Context.Set<T>().Where(predicate).ToList();
}
public bool Exists(Expression<Func<T, bool>> predicate)
{
return Context.Set<T>().Any(predicate);
}
public T First(Expression<Func<T, bool>> predicate)
{
return Context.Set<T>().Where(predicate).FirstOrDefault();
}
public IEnumerable<T> GetAll()
{
return Context.Set<T>().ToList();
}
public IEnumerable<T> GetAllOrderBy(Func<T, object> keySelector)
{
return Context.Set<T>().OrderBy(keySelector).ToList();
}
public IEnumerable<T> GetAllOrderByDescending(Func<T, object> keySelector)
{
return Context.Set<T>().OrderByDescending(keySelector).ToList();
}
public void Commit()
{
Context.SaveChanges();
}
public void Add(T entity)
{
Context.Set<T>().Add(entity);
}
public void Update(T entity)
{
Context.Entry(entity).State = EntityState.Modified;
}
public void Delete(T entity)
{
Context.Set<T>().Remove(entity);
}
public void Dispose()
{
if (Context != null)
{
Context.Dispose();
}
GC.SuppressFinalize(this);
}
}
public class MyContext : DbContext, IUnitOfWork
{
public DbSet<Car> Cars { get; set; }
public void Commit()
{
SaveChanges();
}
protected override void Dispose(bool disposing)
{
IsDisposed = true;
UnitOfWorkFactory.DisposeUnitOfWork(this);
base.Dispose(disposing);
}
public bool IsDisposed { get; private set; }
}
Then I can do:
using (var unitOfWork = UnitOfWorkFactory.Create())
{
_carRepository.Add(new Car
{
Make = "Porshe", Name = "Boxter"
});
_carRepository.Commit();
}
You could use some kind of "current" unit of work which is tied to current thread and explicitly resolved in service code. You need class to hold thread static instance of UoW to achieve this. However, this is not very good solution.
You be the judge...
I think you are double doing it.
Point 1:
http://www.britannica.com/topic/Occams-razor
Point 2:
From the F2 object browser description of EF main object, the DBContext...
public class DbContext
Member of System.Data.Entity
Summary:
A DbContext instance represents a combination of the Unit Of Work and Repository patterns such that it can be used to query from a database and group together changes that will then be written back to the store as a unit.