Service isn't implementing interface member noobie - asp.net-mvc-3

I am re engineering an MVC3 app to take all linq out of controllers and in to proper layers.
I have got this as my structure SQL --> EF --> Repository --> Service --> Controller. I am using interfaces.
When compiling I am getting this error:
gpc.data.service.roleService does not implement interface member gpc.data.interfaces.iroleservice.HolderNamesbyRoleID(int).
I am totally new to proper architecture so apologies if this is blindingly obvious lol. Here is some code:
Repository:
namespace gpc.Data.Repositories
{
public class roleRepository :gpc.Data.Interfaces.IRoleRepository
{
private gpc.Models.gpcEntities _entities = new Models.gpcEntities();
public HolderNames HolderNamesbyRoleID(int roleid)
{
return (from i in _entities.HolderNames
where i.roleid == roleid select i).FirstOrDefault();
}
}
}
I then have an interface:
namespace gpc.Data.Interfaces
{
public interface IRoleRepository
{
HolderNames HolderNamesbyRoleID(int roleid);
}
}
Then I have the service:
namespace gpc.Data.Service
{
public class roleService : gpc.Data.Interfaces.IRoleService
{
private ModelStateDictionary _modelState;
private gpc.Data.Interfaces.IRoleRepository _repository;
public roleService(ModelStateDictionary modelState)
{
_modelState = modelState;
_repository = new gpc.Data.Repositories.roleRepository();
}
public roleService(ModelStateDictionary modelState,
gpc.Data.Repositories.roleRepository repository)
{
_modelState = modelState;
_repository = repository;
}
public HolderNames HolderNames(int roleid)
{
return _repository.HolderNamesbyRoleID(roleid);
}
}
}
I then have another interface:
namespace gpc.Data.Interfaces
{
public interface IRoleService
{
HolderNames HolderNamesbyRoleID(int roleid);
}
}
I created a very simple ienumerable in this structure and I was able to get data on to the view through the controller as i would expect. I guess that as this one is a bit more complicated that a select everything and throw it at a view I must have missed something. I don't know if it makes a difference, but "holdernames" is a SQL view as opposed to a table.
Any help greatly appreciated

It's basically just what your compiler error shows. Your IRoleService interface defines a method named HolderNamesbyRoleID, but in your implementation you only have a method named HolderNames.
I assume this is just a mistype on your part.

Interface only contains the signature. You have to write actual implementation in class where you have implemented your interface. In your case you have define method HolderNamesbyRoleID in IRoleRepository but you have not implemented this method in roleService class. You must have to implement HolderNamesbyRoleID in roleService class.
Your roleService class code becomes like below.
namespace gpc.Data.Service
{
public class roleService : gpc.Data.Interfaces.IRoleService
{
private ModelStateDictionary _modelState;
private gpc.Data.Interfaces.IRoleRepository _repository;
public roleService(ModelStateDictionary modelState)
{
_modelState = modelState;
_repository = new gpc.Data.Repositories.roleRepository();
}
public roleService(ModelStateDictionary modelState,
gpc.Data.Repositories.roleRepository repository)
{
_modelState = modelState;
_repository = repository;
}
public HolderNames HolderNamesbyRoleID(int roleid)
{
return _repository.HolderNamesbyRoleID(roleid);
}
}
}
Refer interface for more info.

Related

EF Core 5.0 How to manage multiple entity class with one generic repository

First question here, I hope I'm doing it right.
I'm using Entity Framework Core 5.0 (Code First) with an onion architecture (data/repo/service/mvc) and so I have a service for each table (almost).
It's work well but now I need to manage (get, insert, update, delete) about 150 tables which all have the same structure (Id, name, order).
I have added each of them as Entity class and their DbSet too in my DbContext, but I don't want to make 150 services, I would like to have a generic one .
How can I bind it to my generic repository ?
public class Repository<T> : IRepository<T> where T : BaseEntity
{
private readonly ApplicationContext context;
private DbSet<T> entities;
private readonly RepositorySequence repoSequence;
private string typeName { get; set; }
public Repository(ApplicationContext context)
{
this.context = context;
entities = context.Set<T>();
this.repoSequence = new RepositorySequence(context);
this.typeName = typeof(T).Name;
}
public T Get(long plng_Id)
{
return entities.SingleOrDefault(s => s.Id == plng_Id);
}
[...]
}
In an ideal world, would like to have something like this :
public async Task Insert(dynamic pdyn_Entity)
{
Type DynamicType = Type.GetType(pdyn_Entity);
Repository<DynamicType> vobj_Repo = new Repository<DynamicType>(mobj_AppContext);
long Id = await vobj_Repo.InsertAsync(pdyn_Entity);
}
But I can try to get type from DbSet string Name too, I just managed to retrieve some data :
public IEnumerable<object> GetAll(string pstr_DbSetName)
{
return ((IEnumerable<BaseEntity>)typeof(ApplicationContext).GetProperty(pstr_DbSetName).GetValue(mobj_AppContext, null));
}
I've tried the following method (2.0 compatible apparently) to get the good DbSet, not working neither (no Query) : https://stackoverflow.com/a/48042166/10359024
What am I missing?
Thanks a lot for your help
Not sure why you need to get type?
You can use something like this.
Repository.cs
public class Repository<T> : IRepository<T> where T : BaseEntity
{
private readonly ApplicationContext context;
private DbSet<T> entities;
public Repository(ApplicationContext context)
{
this.context = context;
entities = context.Set<T>();
}
public List<T> Get()
=> entities.ToList();
public T Get(long plng_Id)
=> entities.Find(plng_Id);
public long Save(T obj)
{
if (obj.ID > 0)
entities.Update(obj);
else
entities.Add(obj);
return obj.ID;
}
public void Delete(T obj)
=> entities.Remove(obj);
}
Then you can use either one of these 2 options you want
Multiple repositories following your tables
UserRepository.cs
public class UserRepository : Repository<User> : IUserRepository
{
private readonly ApplicationContext context;
public UserRepository(ApplicationContext context)
{
this.context = context;
}
}
BaseService.cs
public class BaseService : IBaseService
{
private readonly ApplicationContext context;
private IUserRepository user;
private IRoleRepository role;
public IUserRepository User { get => user ??= new UserRepository(context); }
public IRoleRepository Role { get => user ??= new RoleRepository(context); }
public BaseService(ApplicationContext context)
{
this.context = context;
}
}
If you are lazy to create multiple repositories, can use this way also. Your service just simple call Repository with entity name.
BaseService.cs
public class BaseService : IBaseService
{
private readonly ApplicationContext context;
private IRepository<User> user;
private IRepository<Role> role;
public IRepository<User> User { get => user ??= new Repository<User>(context); }
public IRepository<Role> Role { get => role ??= new Repository<Role>(context); }
public BaseService(ApplicationContext context)
{
this.context = context;
}
}
Finally, you can call service like this. You can use multiple services instead of BaseService if you want.
HomeController.cs
public class HomeController : Controller
{
private readonly IBaseService service;
public HomeController(IBaseService service)
{
this.service = service;
}
public IActionResult Index()
{
var user = service.User.Get();
return View(user);
}
public IActionResult Add(User user)
{
var id = service.User.Save(user);
return View();
}
}
I suggest to use first option (multiple repositories) because you may need to customise functions in own repository in future. And create service class following your controller name. For example, you have HomeController, UserController, etc. Create HomeService, UserService and link them with BaseService so that you can create customised functions in their own service class.
I assume you have a base entity like this:
public class BaseEntity
{
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Order { get; set; }
}
Then you can do CRUD operations in your generic repository like this:
public int Create(T item)
{
if (item == null) return 0;
entities.Add(item);////SaveChanges
return item.Id;
}
public void Update(T updatedItem)
{
context.SetModified(updatedItem);//SaveChanges
}
public IQueryable<T> All()
{
return entities();
}
And in each of the methods you have access to your 3 common fields in BaseEntity
Thank you all for your responses.
I need to have the type because I am using a blazor component which automatically binds to these tables. This component has the name of the desired entity class (in string) as a parameter. Thanks to #Asherguru's response I was able to find a way to do this:
1 - I made a 'SedgmentEntity' Class :
public abstract class SegmentEntity : ISegmentEntity
{
public abstract long Id { get; set; }
public abstract string Name { get; set; }
public abstract short? Order { get; set; }
}
2 - A SegmentRepository which is typed via Reflection:
public class SegmentRepository : ISegmentRepository
{
private readonly ApplicationContext context;
private readonly RepositorySequence repoSequence;
public SegmentRepository(ApplicationContext context)
{
this.context = context;
this.repoSequence = new RepositorySequence(context);
}
public async Task<long> Insert(string pstr_EntityType, SegmentEntity pobj_Entity)
{
Type? vobj_EntityType = Assembly.GetAssembly(typeof(SegmentEntity)).GetType("namespace.Data." + pstr_EntityType);
if (vobj_EntityType != null)
{
// create an instance of that type
object vobj_Instance = Activator.CreateInstance(vobj_EntityType);
long? nextId = await repoSequence.GetNextId(GetTableName(vobj_EntityType));
if (nextId == null)
{
throw new TaskCanceledException("Sequence introuvable pour " + vobj_EntityType.FullName);
}
PropertyInfo vobj_PropId = vobj_EntityType.GetProperty("Id");
vobj_PropId.SetValue(vobj_Instance, nextId.Value, null);
PropertyInfo vobj_PropName = vobj_EntityType.GetProperty("Name");
vobj_PropName.SetValue(vobj_Instance, pobj_Entity.Name, null);
PropertyInfo vobj_PropOrder = vobj_EntityType.GetProperty("Order");
vobj_PropOrder.SetValue(vobj_Instance, pobj_Entity.Order, null);
return ((SegmentEntity)context.Add(vobj_Instance).Entity).Id;
}
}
public IEnumerable<object> GetAll(string pstr_EntityType)
{
Type? vobj_EntityType = Assembly.GetAssembly(typeof(SegmentEntity)).GetType("namespace.Data." + pstr_EntityType);
if (vobj_EntityType != null)
{
PropertyInfo vobj_DbSetProperty = typeof(ApplicationContext).GetProperties().FirstOrDefault(prop =>
prop.PropertyType.FullName.Contains(vobj_EntityType.FullName));
return (IEnumerable<object>)vobj_DbSetProperty.GetValue(context, null);
}
return null;
}
}
I still have to handle the Get and the Delete functions but it should be fine.
Then I will be able to create a single service which will be called by my component.
Thanks again !

ObjectContext not retrieving recent changes

This code works fine, However, if I run execute a storedprocedure in my unit of work class (or any update, delete, add operation), I'm still getting original the data. Actually, I have already a solution(posted below in controller) but Im sure this is not the most elegant way, I hope someone can help me refactor the code. please help. Thanks
My unit of work
public class UnitOfWork : IUnitOfWork, IDisposable
{
private readonly ObjectContext _context;
private BookRepository _books;
public UnitOfWork(ObjectContext context)
{
if (context == null)
{
throw new ArgumentNullException("Context was not supplied");
}
_context = context;
}
public IRepository<Book> Books
{
get
{
if (_books== null)
{
_books= new BookRepository (_context);
}
return _books;
}
}
public void UpdateAuthor(int id)
{
_context.ExecuteStoreCommand("sp_UpdateAuthor #param1",
new SqlParameter("param1", id));
}
public void Commit()
{
_context.SaveChanges();
}
Book Repository
public class BookRepository : Repository<Book>
{
public BookRepository (ObjectContext context)
: base(context)
{
}
public override Machine GetById(object id)
{
return _objectSet.SingleOrDefault(s => s.Id== (int)id);
}
}
Generic Repository
public abstract class Repository<T> : IRepository<T>
where T : class, IAuditEntity
{
protected IObjectSet<T> _objectSet;
public Repository(ObjectContext context)
{
_objectSet = context.CreateObjectSet<T>();
}
public abstract T GetById(object id);
public IEnumerable<T> GetAll()
{
return _objectSet;
}
public IEnumerable<T> Query(Expression<Func<T, bool>> filter)
{
return _objectSet.Where(filter);
}
public void Add(T entity)
{
_objectSet.AddObject(entity);
}
public void Remove(T entity)
{
_objectSet.DeleteObject(entity);
}
}
Controller Code
public class HomeController : Controller
{
private IUnitOfWork _unitOfWork;
#region Core Action Methods
public HomeController()
{
this._unitOfWork = new UnitOfWork(((IObjectContextAdapter)new BookContext()).ObjectContext);
}
private IEnumerable<BookViewModel> GetBookdsViewModels(int id)
{
//THE CODE WHERE ITS NOT RETURNING THE UPDATED VLAUES
//var query = _unitOfWork.Books.GetAll().Where(d => d.Id== id);
//I WANT TO CHANGE THIS CODE
ObjectContext objectContext = ((IObjectContextAdapter)new BookContext()).ObjectContext;
ObjectSet<Book> set = objectContext.CreateObjectSet<Book>();
set.MergeOption = MergeOption.OverwriteChanges;
var query = from a in set
where a.Id== id && !a.IsDeleted
select a;
return query
.Select(
c => new BookViewModel
{
Id = c.Id ,
Name = c.Name
});
}
I believe the problem is because you're executing things directly against your database, and then trying to refer back to the local copy that's stored in your repository and they're different.
public void UpdateAuthor(int id)
{
_context.ExecuteStoreCommand("sp_UpdateAuthor #param1",
new SqlParameter("param1", id));
}
When you run this query, you're making a change in your db instead of your local - why dont you do something like this:
public void UpdateAuthor(int id)
{
var book = Books.GetById(id);
/* make changes to your book object */
_unit.Save();
}
If you're wanting to make changes using store procs, you're going to have to dispose of your context, and recreate the repo's so that you're working with data from the DB instead of the local copy.
Expanding on Mark Oreta's answer, you need to ensure your Model is updated after manually executing a stored proc on your database. If you must manually call that stored proc then try this afterward:
_context.Entry<Book>(instanceOfAuthor).Reload();
Which might be:
_context.Entry<Book>(_context.Books.GetById(id)).Reload();

Entity framework: ObjectContext and inheritance

I need to have a CRUd operations on my class (CompetenceSpecific).
Competence has three derived classes - CompetenceFunction, CompetenceArea and CompetenceSpecifc
The error I recieved:
There are no EntitySets defined for the specified entity type 'CompetencyManagement.Domain.Entities.CompetenceFunction'. If 'CompetencyManagement.Domain.Entities.CompetenceFunction' is a derived type, use the base type instead. Parameter name: TEntity
How should I correct this? Please suggest a solution that would solve my problem. Thanks
Please check the code below, I removed some parts of the code for simplicity.
--MODEL
public class Competence
{
public int CompetenceID { get; set; }
public int CourseID { get; set; }
...
}
public class CompetenceFunction : Competence
{
}
--REPOSITORY and interfaces
public interface IRepository<T> where T : class
{
T GetById(object id);
IEnumerable<T> GetAll();
IEnumerable<T> Query(Expression<Func<T, bool>> filter);
void Add(T entity);
void Remove(T entity);
}
public abstract class Repository<T> : IRepository<T>
where T : class
{
protected IObjectSet<T> _objectSet;
public Repository(ObjectContext context)
{
_objectSet = context.CreateObjectSet<T>();
}
...
}
public class CompetenceFunctionRepository : Repository<CompetenceFunction>
{
public CompetenceFunctionRepository(ObjectContext context)
: base(context)
{
}
public override CompetenceFunction GetById(object id)
{
return _objectSet.SingleOrDefault(s => s.CompetenceID == (int)id);
}
}
--UNIT oF WORK
public interface IUnitOfWork
{
IRepository<CompetenceFunction> CompetenceFunctions { get; }
IRepository<CompetenceArea> CompetenceAreas { get; }
IRepository<CompetenceSpecific> CompetenceSpecifics { get; }
void Commit();
}
public class UnitOfWork : IUnitOfWork, IDisposable
{
private CompetenceFunctionRepository _competencefunction;
private CompetenceAreaRepository _competencearea;
private CompetenceSpecificRepository _competencespecifc;
public UnitOfWork(ObjectContext context)
{
if (context == null)
{
throw new ArgumentNullException("Context was not supplied");
}
_context = context;
}
#region IUnitOfWork Members
public IRepository<CompetenceFunction> CompetenceFunctions
{
get
{
if (_competencefunction == null)
{
_competencefunction = new CompetenceFunctionRepository(_context);
}
return _competencefunction;
}
}
public IRepository<CompetenceArea> CompetenceAreas
{
get
{
if (_competencearea == null)
{
_competencearea = new CompetenceAreaRepository(_context);
}
return _competencearea;
}
}
public IRepository<CompetenceSpecific> CompetenceSpecifics
{
get
{
if (_competencespecifc == null)
{
_competencespecifc = new CompetenceSpecificRepository(_context);
}
return _competencespecifc;
}
}
--Im getting an error in this part of Repository
public Repository(ObjectContext context)
{
_objectSet = context.CreateObjectSet<T>();
}
There are no EntitySets defined for the specified entity type 'CompetencyManagement.Domain.Entities.CompetenceFunction'. If 'CompetencyManagement.Domain.Entities.CompetenceFunction' is a derived type, use the base type instead. Parameter name: TEntity
Here's how I implement in the controller
private IUnitOfWork _unitOfWork;
var a = _unitOfWork.CompetenceFunctions.GetAll();
return View(a);
You have to get derived type by the OfType function, e.g.
context.CreateObjectSet<Competence>().OfType<CompetenceFunction>()
In your case that would mean that there is only a CompetenceRepository that serves all derivatives of Competence.
Edit
(After your comment)
First, UoW is meant for temporarily storing changes that should be dealt with in one batch (like changes to be committed to the database). GetAll and similar functions are repository stuff.
But do you need repositories? I like this post. When beginning to know EF, I would focus on the ins and outs of EF without getting distracted too much by surrounding architecture. E.g. start with services that at the inside communicate directly with the context and expose methods like GetCompetenceFunctions, GetCompetenceAreas (using OfType), and SaveCompetenceFunction, ....
You can address these service methods directly from action methods in the MVC controllers.

Repository Pattern and Azure Table Storage(???)

While doing the following simple example, I found the following difficulties
As the title says, I am intending to use the Repository pattern while I am storing data in the Azure table storage.now I have couple of classes, Repository.cs, IRepository.cs, DataContext.cs and the Controller.
During my reading I found some info and been doing as follows.
IRepository.cs
public interface IRepository<T> where T: TableServiceEntity
{
T GetById(int Id);
IQueryable<T> GetAll();
}
and the DataContext.cs
public class DataContext<T>:TableServiceContext where T:TableServiceEntity
{
public DataContext(CloudStorageAccount storageaccount, StorageCredentials credentials)
: base(storageaccount.TableEndpoint.AbsoluteUri, credentials)
{
// _storageAccount = storageaccount;
var storageAccount = CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue(KEY_STORAGE));
storageAccount.CreateCloudTableClient().CreateTableIfNotExist(tableName);
}
public IQueryable<T> DeviceTable
{
get { return CreateQuery<T>(tableName); }
}
}
plus some part of the controller(I have already data in the table which I created before)
public class DeviceMeController : Controller
{
private IRepository<Entity>_repository;
public Controller() : this(new Repository<Entity>())
{
}
public Controller(IRepository<Entity> repository)
{
_repository = repository;
}
public ActionResult Index()
{
var List = _repository.GetAll();
return View(deviceList);
}
and the the Implementation of the interface Reposistory.cs, here is where I have an error and got lost somewhere
public class Repository<T>:IRepository<T> where T:TableServiceEntity
{
private DataContext<T> _serviceContext;
// here get tablename as pararameter;
// so the Enities call this function
public Repository()
{
// the same context for multiple tables ?
}
// perhaps it should take the table Name
public void Add(T item)
{
_serviceContext.AddObject(TableName,item);
_serviceContext.SaveChangesWithRetries();
}
public IQueryable<T> GetAll()
{
var results = from c in _serviceContext.Table
select c;
return results;
Error is about the null reference, the debugger shows the variable results is null?
In the end I need to know few things.
what should I do in the Repository.cs constructor? I believe the Datacontext.cs class has to be in a separate class ...
any Hint here
Hy,
first of all I presume you left out some code, because I don't see how you get your context in your repository. But supposing you do set it correctly, (injection?) taking into account the way you desinged your datacontext the repository doesn't need to know the table name because it is set in the following lines of code:
public IQueryable<T> DeviceTable
{
get { return CreateQuery<T>(Constants.DeviceTableName); }
}
So when you create a query based on the IQueryable DeviceTable, the table name is already set.
The thing is I don't see the need for your context class, especially as it can only bring over a single entity type (it is generic and based on an entity).
A basic layout of my Repository for Azure Table Storage is:
public abstract class CloudRepository<TEntity> : ICloudRepository<TEntity>
{
private TableServiceContext _tableServiceContext;
private string _tableName;
public string TableName
{
get { return _tableName ?? ( _tableName = typeof(TEntity).Name.Replace("Entity", string.Empty).ToLower()); }
}
public CloudStorageAccount StorageAccount
{
get
{
return CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue("StorageConnectionString"));
}
}
public CloudTableClient TableClient
{
get
{
CloudTableClient cloudTableClient = StorageAccount.CreateCloudTableClient();
cloudTableClient.CreateTableIfNotExist(TableName);
return cloudTableClient;
}
}
public TableServiceContext ServiceContext
{
get
{
return _tableServiceContext ?? (_tableServiceContext = TableClient.GetDataServiceContext());
}
}
public IEnumerable<TEntity> FindAll()
{
return ServiceContext.CreateQuery<TEntity>(TableName).ToList();
}
}
Hope this helps you.

Ninject, Repository and DAL

I am new to MVC, repository concept and dependency injection.
My repository and DAL looks like
public interface IRepository<TEntity> where TEntity : class
{
List<TEntity> FetchAll();
IQueryable<TEntity> Query { get; }
void Add(TEntity entity);
void Delete(TEntity entity);
void Save();
}
public class Repository<T> : IRepository<T> where T : class
{
private readonly DataContext _db;
public Repository(DataContext db)
{
_db = db;
}
#region IRepository<T> Members
public IQueryable<T> Query
{
get { return _db.GetTable<T>(); }
}
public List<T> FetchAll()
{
return Query.ToList();
}
public void Add(T entity)
{
_db.GetTable<T>().InsertOnSubmit(entity);
}
public void Delete(T entity)
{
_db.GetTable<T>().DeleteOnSubmit(entity);
}
public void Save()
{
_db.SubmitChanges();
}
#endregion
}
In Global.asax file I have
private void RegisterDependencyResolver()
{
var kernel = new StandardKernel();
kernel.
Bind(typeof(IRepository<>)).
To(typeof(Repository<>))
.WithConstructorArgument("db", new DataContext(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString()));
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
}
but when I am trying to access repository I get "Object reference not set to an instance of an object". Do I understand correctly how Repository and Injection should work?
public class AdminController : Controller
{
private readonly IRepository<User> _userRepository;
public ActionResult Index()
{
var a = _userRepository.FetchAll(); //I get exception here
return View();
}
}
You get nullref because you don't set _userRepository. Set it in the AdminControllers constructor and Niject will inject it happily:
public class AdminController : Controller
{
private readonly IRepository<User> _userRepository;
public AdminController(IRepository<User> userRepository)
{
_userRepository = userRepository;
}
//...
}
You can read here more about the injection patterns with Ninject and how injection works.
In the web config file
<appSettings>
<add key="RepoSetting" value="Solution.DAL.OrderRepository"/>
</appSettings>
In the ninject web common class
private static void RegisterServices(Ikernel Kernel)
{
//kernl.Bind<Irepo>().To<CustRepo>();
string name = WebConfigurationManager.AppSettings["RepoSetting"];
Type repoToInject = Assembly.GetExecutingAssembly().GetType(name);
kernel.Bind<ICustomerRepository>().To(repoToInject
}

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