Use automapper to set creation time and last edit time - asp.net-core-mvc

In my MVC Core 2 application i use Automapper to map from resource classes to dto classes.
Some of my dto classes inherits from a base class with this properties:
ID
CREATED
UPDATED
I create this kind of mapping for one inherited class:
CreateMap<AnagraficaCompletaResource, ANAGRAFI>()
.ForMember(d => d.CREATED, option => { option.Condition(s => {return (s.ID == 0);}); option.MapFrom(s => DateTime.Now);})
.ForMember(d => d.UPDATED, opt => opt.MapFrom(s => DateTime.Now));
Can I create a generic mapping for all the classes that inherit from th base class?
My resource class don't have Created and Updated properties.
Thank you.

It is not reasonable to set CREATED and UPDATED by Automapper. First, the Creation Time should be the time when saving the record to databse instead of mapping time, second, ANAGRAFI is a new empty instance when mapping, you would not be able to decide whether it is create or update operation.
For standard way, you could try to set these field during SaveChanges or SaveChangesAsync.
BaseEntity
public class BaseEntity
{
public DateTime? DateCreated { get; set; }
public DateTime? DateModified { get; set; }
}
SchoolContext
public class SchoolContext : DbContext
{
public DbSet<Student> Students { get; set; }
public override int SaveChanges()
{
SetCreatedAndModified();
return base.SaveChanges();
}
public override async Task<int> SaveChangesAsync()
{
SetCreatedAndModified();
return await base.SaveChangesAsync();
}
private void SetCreatedAndModified()
{
var entities = ChangeTracker.Entries().Where(x => x.Entity is BaseEntity && (x.State == EntityState.Added || x.State == EntityState.Modified));
foreach (var entity in entities)
{
if (entity.State == EntityState.Added)
{
((BaseEntity)entity.Entity).DateCreated = DateTime.UtcNow;
}
((BaseEntity)entity.Entity).DateModified = DateTime.UtcNow;
}
}
}

Related

ASPNET Boilerplate, extending audit log

I am trying to extend the AuditLog entity in ASPNETBOILETPLATE framework in order to add some new properties to it. I have tried to extend the AuditLog class (ExtendedAuditInfo) and implement a customised version of AuditStore Class (ExtendedAuditStore). However, I am not able to inject my new ExtendedAuditInfo in the constructor and receive two error messages regarding unmatching input parameters in the Constructor and SaveAsync method.
Class ExtendedAuditInfo:
public class ExtendedAuditInfo : AuditInfo
{
// Some properties
}
Class ExtendedAuditStore:
public class ExtendedAuditStore : AuditingStore
{
public ExtendedAuditStore(IRepository<ExtendedAuditInfo, long> auditLogRepository)
: base(auditLogRepository)
{
}
public override Task SaveAsync(ExtendedAuditInfo auditInfo)
{
if (!string.IsNullOrEmpty(auditInfo.Parameters) && auditInfo.Parameters != "{}")
{
var parameters = JsonConvert.DeserializeObject<AuditParameterInput>(auditInfo.Parameters);
if (parameters != null)
auditInfo.CustomData = parameters.Input.Id.ToString();
}
return base.SaveAsync(auditInfo);
}
}
The errors are:
cannot convert from 'Abp.Domain.Repositories.IRepository<SixB.Serafina.Auditing.ExtendedAuditInfo, long>' to 'Abp.Domain.Repositories.IRepository<Abp.Auditing.AuditLog, long>'
and
no suitable method found to override
The procedure above is based on the idea that I found Here
I found the solution based on the official document of How To Extend Existing Entities.
In order to extend the AuditLog class, inheritance must be used. Therefore a new class, let's say ExtendedAuditInfo needs to be inherited from AuditLog.
public class ExtendedAuditLog : AuditLog
{
public ExtendedAuditLog()
{
}
public ExtendedAuditLog(AuditInfo auditInfo)
{
this.BrowserInfo = auditInfo.BrowserInfo;
this.ClientIpAddress = auditInfo.ClientIpAddress;
this.ClientName = auditInfo.ClientName;
this.CustomData = auditInfo.CustomData;
this.Exception = auditInfo.Exception?.Message.ToString() + "";
this.ExecutionDuration = auditInfo.ExecutionDuration;
this.ExecutionTime = auditInfo.ExecutionTime;
this.ImpersonatorTenantId = auditInfo.ImpersonatorTenantId;
this.ImpersonatorUserId = auditInfo.ImpersonatorUserId;
this.MethodName = auditInfo.MethodName;
this.Parameters = auditInfo.Parameters;
this.ReturnValue = auditInfo.ReturnValue;
this.ServiceName = auditInfo.ServiceName;
this.TenantId = auditInfo.TenantId;
this.UserId = auditInfo.UserId;
}
//new properties
}
This class has to be added to the context and obviously, a new migration needs to be run in order to add the new properties.
public class ProjectDbContext : AbpZeroDbContext<Tenant, Role, User, ProjectDbContext >
{
/* Define a DbSet for each entity of the application */
public SerafinaDbContext(DbContextOptions<SerafinaDbContext> options)
: base(options)
{
}
public virtual DbSet<County> Counties { get; set; }
public virtual DbSet<Country> Countries { get; set; }
public virtual DbSet<Currency> Currencies { get; set; }
public virtual DbSet<OrganisationType> OrganisationTypes { get; set; }
public virtual DbSet<ExtendedAuditLog> ExtendedAuditLogs { get; set; }
}
Finally, in the ExtendedAuditStore class, IRepository<ExtendedAuditLog, long> _extendedAuditLogRepository has to be injected as a second parameter of the constructor and can be used to insert the extended entity.
public class ExtendedAuditStore : AuditingStore
{
IRepository<ExtendedAuditLog, long> _extendedAuditLogRepository;
public ExtendedAuditStore(
IRepository<AuditLog, long> auditLogRepository,
IRepository<ExtendedAuditLog, long> extendedAuditLogRepository
)
: base(auditLogRepository)
{
_extendedAuditLogRepository = extendedAuditLogRepository;
}
public override async Task SaveAsync(AuditInfo auditInfo)
{
if (auditInfo.Exception != null)
await base.SaveAsync(auditInfo);
var auditLog = new ExtendedAuditLog(auditInfo);
//new properties can be set here
await _extendedAuditLogRepository.InsertAsync(auditLog);
}
}
Also, instead of inheriting from AuditingStore, a new implementation for IAuditingStore can be created and injected into application services.
UPDATE:
Finally, all you need is to replace the default AuditingStore in StartUp class:
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddTransient<IAuditingStore, ExtendedAuditStore>();
}

MVC 6 EF7 RC1 creating multiple dbcontexts

I am trying to figure out how to create a second DB context in EF7 RC1. In the past I could use a constructor with :base("connectionName") but that no longer seems an option since it says cannot convert string to System.IServiceProvider.
My second context code is as follows:
public class DecAppContext : DbContext
{
public DecAppContext()
// :base("DefaultConnection")
{
}
public DbSet<VignetteModels> VignetteModels { get; set; }
public DbSet<VignetteResult> Result { get; set; }
}
}
In my config.json I have the connection specified:
"Data": {
"DefaultConnection": {
"ConnectionString": "Server=(localdb)\\mssqllocaldb;Database=aspnet5-xxxxx...;Trusted_Connection=True;MultipleActiveResultSets=true"
}
}
In my configure services section of my startup I have both contexts added:
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]))
.AddDbContext<DecAppContext>(options => options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
The applicationDB context works fine since I can create a user and login without issue
However when I try to access the other context as in my controller via:
private DecAppContext db = new DecAppContext();
var vignette = db.VignetteModels.SingleOrDefault(v => v.CaseId == vid);
I get the error:
No database providers are configured. Configure a database provider by
overriding OnConfiguring in your DbContext class or in the
AddDbContext method when setting up services.
Any working examples in EF7 RC1 with multiple db contexts and accessing them would be much appreciated.
First of all I would recommend you the article from the wiki of EntityFramework on GitHub. The article describes many ways to define DbContext, which references to a section of appsettings.json. I personally prefer the way with the usage of [FromServices] attribute.
The code could be about the following:
First of all you defined appsettings.json with the following content
{
"Data": {
"ApplicationDbConnectionString": "Server=(localdb)\\mssqllocaldb;Database=ApplicationDb;Trusted_Connection=True;MultipleActiveResultSets=true",
"DecAppDbConnectionString": "Server=Server=(localdb)\\mssqllocaldb;Database=DecAppDb;Trusted_Connection=True;MultipleActiveResultSets=true"
}
}
where you define two connection strings.
Seconds you declare the classes DecAppContext and ApplicationDbContext which have DbContext as the base class. The simplest form will be just
public class ApplicationDbContext : DbContext
{
}
public class DecAppContext : DbContext
{
}
without any DbSet properties.
Third Step. You use Microsoft.Extensions.DependencyInjection to inject the database contexts. To do this you need just include in Startup.cs something like
public class Startup
{
// property for holding configuration
public IConfigurationRoot Configuration { get; set; }
public Startup(IHostingEnvironment env)
{
// Set up configuration sources.
var builder = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
.AddEnvironmentVariables();
// save the configuration in Configuration property
Configuration = builder.Build();
}
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.
services.AddMvc()
.AddJsonOptions(options => {
options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
});
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApplicationDbContext>(options => {
options.UseSqlServer(Configuration["Data:ApplicationDbConnectionString"]);
})
.AddDbContext<DecAppContext>(options => {
options.UseSqlServer(Configuration["Data:DecAppDbConnectionString"]);
});
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
...
}
}
Se create two DbContext (DecAppContext and ApplicationDbContext) using the configuration "Data:DecAppDbConnectionString" and "Data:ApplicationDbConnectionString".
Now we can just use the context in the controller. For example
[Route("api/[controller]")]
public class UsersController : Controller
{
[FromServices]
public ApplicationDbContext ApplicationDbContext { get; set; }
[FromServices]
public DecAppContext DecAppContext { get; set; }
[HttpGet]
public IEnumerable<object> Get() {
var returnObject = new List<dynamic>();
using (var cmd = ApplicationDbContext.Database.GetDbConnection().CreateCommand()) {
cmd.CommandText = "SELECT Id, FirstName FROM dbo.Users";
if (cmd.Connection.State != ConnectionState.Open)
cmd.Connection.Open();
var retObject = new List<dynamic>();
using (var dataReader = cmd.ExecuteReader())
{
while (dataReader.Read())
{
var dataRow = new ExpandoObject() as IDictionary<string, object>;
for (var iFiled = 0; iFiled < dataReader.FieldCount; iFiled++)
dataRow.Add(
dataReader.GetName(iFiled),
dataReader.IsDBNull(iFiled) ? null : dataReader[iFiled] // use null instead of {}
);
retObject.Add((ExpandoObject)dataRow);
}
}
return retObject;
}
}
}
or the same using async/await:
[Route("api/[controller]")]
public class UsersController : Controller
{
[FromServices]
public ApplicationDbContext ApplicationDbContext { get; set; }
[FromServices]
public DecAppContext DecAppContext { get; set; }
[HttpGet]
public async IEnumerable<object> Get() {
var returnObject = new List<dynamic>();
using (var cmd = ApplicationDbContext.Database.GetDbConnection().CreateCommand()) {
cmd.CommandText = "SELECT Id, FirstName FROM dbo.Users";
if (cmd.Connection.State != ConnectionState.Open)
cmd.Connection.Open();
var retObject = new List<dynamic>();
using (var dataReader = await cmd.ExecuteReaderAsync())
{
while (await dataReader.ReadAsync())
{
var dataRow = new ExpandoObject() as IDictionary<string, object>;
for (var iFiled = 0; iFiled < dataReader.FieldCount; iFiled++)
dataRow.Add(dataReader.GetName(iFiled), dataReader[iFiled]);
retObject.Add((ExpandoObject)dataRow);
}
}
return retObject;
}
}
}
One can just declare the property public ApplicationDbContext ApplicationDbContext { get; set; } with the attribute [FromServices] and ASP.NET initialize it from the context injected in ConfigureServices. In the same way one can use the second context DecAppContext whenever you need it.
The above code example will execute SELECT Id, FirstName From dbo.Users in the database context and return JSON data in the form [{"id":123, "firstName":"Oleg"},{"id":456, "firstName":"Xaxum"}]. The conversion of property names from Id and FirstName to id and firstName will be done automatically during serialization because of usage AddJsonOptions in ConfigureServices.
UPDATE: I have to reference the announcement. The next version of MVC (RC2) will require to change the above code to use [FromServices] as additional parameter (of method Get() for example) instead of usage public property [FromServices] public ApplicationDbContext ApplicationDbContext { get; set; }. One will need to remove the property ApplicationDbContext and to add additional parameter to Get() method: public async IEnumerable<object> Get([FromServices] ApplicationDbContext applicationDbContext) {...}. Such changes can be easy done. See here and example of the changes in the demo example of MVC:
[Route("api/[controller]")]
public class UsersController : Controller
{
[HttpGet]
public async IEnumerable<object> Get(
[FromServices] ApplicationDbContext applicationDbContext,
[FromServices] DecAppContext decAppContext)
{
var returnObject = new List<dynamic>();
// ... the same code as before, but using applicationDbContext
// and decAppContext parameters instead of ApplicationDbContext
// and DecAppContext properties
}

How to unit test child validators with When() condition with FluentValidation.TestHelper

The extension method .ShouldHaveChildValidator() in the FluentValidation.TestHelper namespace doesn't have an overload that takes the model. How do I then test that the child validators are set up correctly when using a When() clause like in the following example?
E.g.
public class ParentModel
{
public bool SomeCheckbox { get; set; }
public ChildModel SomeProperty { get; set; }
}
public class ParentModelValidator : AbstractValidator<ParentModel>
{
RuleFor(m => m.SomeProperty)
.SetValidator(new ChildModelValidator())
.When(m => m.SomeCheckbox);
}
I want to Assert that if SomeCheckbox is true, then the child validator is present, and if SomeCheckbox is false, then the child validator isn't present.
I have the following so far in the unit test:
ParentModelValidator validator = new ParentModelValidator();
validator.ShouldHaveChildValidator(
m => m.SomeProperty,
typeof(ChildModelValidator));
but that doesn't take into account the .When() condition.
I notice other methods in the FluentValidation.TestHelper namespace such as .ShouldHaveValidationErrorFor() have an overload that takes the model, so it's easy to test a simple property type with a When() clause by setting up a model that satisfies the precondition.
Any ideas?
Here's a snippet of how I achieve this:
public class ParentModelSimpleValidator : AbstractValidator<ParentModel>
{
public ParentModelSimpleValidator()
{
When(x => x.HasChild, () =>
RuleFor(x => x.Child)
.SetValidator(new ChildModelSimpleValidator()));
}
}
public class ChildModelSimpleValidator : AbstractValidator<ChildModel>
{
public ChildModelSimpleValidator()
{
RuleFor(x => x.ChildName)
.NotEmpty()
.WithMessage("Whatever");
}
}
Here's the relevant simplified models:
[Validator(typeof(ParentModelSimpleValidator))]
public class ParentModel
{
public bool HasChild { get { return Child != null; } }
public ChildModel Child { get; set; }
}
[Validator(typeof(ChildModelSimpleValidator))]
public class ChildModel
{
public string ChildName { get; set; }
public int? ChildAge { get; set; }
}
Here's a sample unit test:
[TestMethod]
public void ShouldValidateChildIfParentHasChild()
{
var validator = new ParentModelSimpleValidator();
var model = new ParentModel
{
ParentName = "AABBC",
Child = new ChildModel { ChildName = string.Empty }
};
validator.ShouldHaveErrorMessage(model, "Whatever");
}
very late to the game here, but I just started using FluentValidation and that was my solution
public class ParentValidator: AbstractValidator<ParentModel>
{
public ParentValidator()
{
// other rules here
// use == for bool?
When(model => model.SomeBoolProperty == false, () => RuleFor(model => model.ChildClass).SetValidator(new ChildClassValidator()));
}
}
public class ChildClassValidator: AbstractValidator<ChildClass>
{
public ChildClassValidator()
{
this
.RuleFor(model => model.SomeProperty).NotNull();
}
}
then the test is
[TestMethod]
public void ParentValidator_should_have_error_in_child_class_property_when_bool_is_false_on_parent()
{
// Arrange - API does not support typical unit test
var validator = new ParentValidator()
var foo = new ParentModel() { SomeBoolProperty = false };
foo.ChildClass.SomeProperty = null;
// Act
var result = validator.Validate(foo);
// Assert - using FluentAssertions
result.Errors.Should().Contain(err => err.PropertyName == "ChildClass.SomeProperty");
}

Implementing Unique Contraint with ValidateEntity gives "The given key was not present in the dictionary" error

While in search of trying to implement unique key validations for my db using EF CodeFirst/Mvc3 I came upon this post http://blogs.msdn.com/b/adonet/archive/2011/05/27/ef-4-1-validation.aspx which gave an example on how to do it by using IValidateObject for my object model:
public class Category : IValidatableObject
{
public int CategoryID { get; set; }
public string CategoryName { get; set; }
public string Description { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
var testContext = (TestContext)validationContext.Items["Context"];
if (testContext.Categories.Any(
c => c.CategoryName == CategoryName && c.CategoryID != CategoryID))
{
yield return new ValidationResult("A category with the same name already exists!", new[] { "CategoryName" });
}
yield break;
}
}
and overriding DbEntityValidationResult ValidateEntity:
public class TestContext : DbContext
{
public DbSet<Test.Models.Category> Categories { get; set; }
protected override DbEntityValidationResult ValidateEntity( DbEntityEntry entityEntry, IDictionary<object, object> items)
{
var myItems = new Dictionary<object, object>();
myItems.Add("Context", this);
return base.ValidateEntity(entityEntry, myItems);
}
}
And the action on the controller
[HttpPost]
public ActionResult Create(Category category)
{
if (ModelState.IsValid) {
categoryRepository.InsertOrUpdate(category);
categoryRepository.Save();
return RedirectToAction("Index");
} else {
return View();
}
}
But I get the error: "The given key was not present in the dictionary." for the line
var testContext = (TestContext)validationContext.Items["Context"];
It seems like Validate on the object is getting called which accesses "Context" before its set in the override ValidateEntity code.
At first I thought it could have been ModelState.Isvalid triggering validate too early but it wasn't.
Anyone know what I'm missing here or what I'm doing wrong? Thanks in advance.
Model.IsValid definitely triggers it too early and perhaps something else. IValidatableObject is global interface used by both MVC and EF but your method in DbContext is called only when you call SaveChanges on the context so any usage of IValidatableObject prior to calling SaveChanges will result in the exception. You must use another approach if you want to validate your entity this way. For example store context in HttpContext.Items - you can create custom action filter and instantiate and store the context before the operation call and dispose it after operation call - hopefully it will cover all problems.
I was facing the same problem... Then after a lot of Googling I finally found this:
Exercise 3: Using IValidatableObject Custom Validation
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
MusicStoreEntities storeDB = new MusicStoreEntities();
if (storeDB.Albums.Any(
a => a.Title.Trim().ToUpper() == this.Title.Trim().ToUpper() &&
a.ArtistId == (int)this.ArtistId))
{
yield return new ValidationResult("Existing Album", new string[] { "Title" });
}
}
As you see in their example, they instantiate a new Context and as such there's no need for validationContext.Items["Context"];. Doing so we won't get this error anymore.

ASP.NET MVC Patterns

I am fairly new to MVC, but after playing with it (MVC 3/Razor), I am hooked.
I have a few questions:
1) What is the best, or most widely used pattern to develop MVC apps in? Repository, DDD, UOW?
2) I am using the Entity Framework 4, so could some please explain to me or point me to a good source that will explain the Repository Pattern w/EF4? Doesn't EF4 take place as the business layer and the data access layer? Does the Repository Pattern even provide a benefit?
3) Also, one last question, could someone explain the whole relationship between the Controller, the Model and the View? I get the basics, but maybe a little more in depth of the correct way to use it. View Models - Say I have a view that displays customer info, and one that edits it, should I have a view model and an edit model, or can the be passed around?
4) Examples??
Thanks for the help up front,
$("Sam")
** EDIT **
Am I on the right track here:
Public Class HomeController
Inherits System.Web.Mvc.Controller
Function Index(ByVal id As Integer) As ActionResult
Return View(New HomeModel)
End Function
<HttpPost()> _
Function Index(ByVal Model As HomeModel) As ActionResult
Return View(Model)
End Function
End Class
Public Class HomeModel
Private _Repository As IRepository(Of Customer)
Public Property Customer As Customer
Public Sub New()
End Sub
Public Sub New(ByVal ID As Integer)
_Repository = New CustomerRepository
Customer = _Repository.GetByID(ID)
End Sub
End Class
Public Interface IRepository(Of T)
Function GetByID(ByVal ID As Integer) As T
Sub Add(ByVal Entity As T)
Sub Delete(ByVal Entity As T)
End Interface
Public Class CustomerRepository
Implements IRepository(Of Customer)
Public Sub Add(ByVal Entity As Customer) Implements IRepository(Of Customer).Add
End Sub
Public Sub Delete(ByVal Entity As Customer) Implements IRepository(Of Customer).Delete
End Sub
Public Function GetByID(ByVal ID As Integer) As Customer Implements IRepository(Of Customer).GetByID
Return New Customer With {.ID = ID, .FirstName = "Sam", .LastName = "Striano"}
End Function
End Class
Public Class Customer
Public Property ID As Integer
Public Property FirstName As String
Public Property LastName As String
End Class
I use generic repositories that get instantiated in a service class (using Dependency Injection with Ninject).
The service class essentially performs two functions:
It provides all the methods that the controller will consume.
It has a property called ViewModel, that essentially maps the data that the views need into a MyViewModel class.
The Controller consumes the service class. With this "pattern", your controllers look like:
namespace ES.eLearningFE.Areas.Courses.Controllers
{
public partial class CourseController : Controller
{
ICourseDisplayService service;
public CourseController(ICourseDisplayService service)
{
this.service = service;
}
public virtual ActionResult Display(int CourseId, int StepOrder, string PupilName, string TutorName)
{
service.CourseId = CourseId;
service.StepOrder = StepOrder;
service.PupilName = PupilName;
service.TutorName = TutorName;
if (Request.IsAjaxRequest())
{
return PartialView(service.ViewModel);
}
else
{
return View(service.ViewModel);
}
}
}
}
The ViewModel class only hold display data and no methods (except the odd really simple method to retrieve data from another property that is, for example a List<> object).
Works really well. An example of a service class:
namespace ES.eLearning.Domain.Services.Courses
{
public class SqlCourseDisplayService : ICourseDisplayService
{
DataContext db;
public SqlCourseDisplayService(DbDataContextFactory contextFactory)
{
db = contextFactory.Make();
CoursesRepository = new SqlRepository<Course>(db);
StepsRepository = new SqlRepository<CourseStep>(db);
StepLinksRepository = new SqlRepository<StepLink>(db);
UserCoursesRepository = new SqlRepository<UserCourse>(db);
CourseTutorsRepository = new SqlRepository<CourseTutor>(db);
UsersRepository = new SqlRepository<User>(db);
}
#region ICourseDisplayService Members
public ViewModels.CourseDisplayVM ViewModel
{
get
{
return new ViewModels.CourseDisplayVM
{
CourseId = this.CourseId,
CourseName = this.Course.Name,
Steps = this.Steps,
ActiveStepIndex = this.ActiveStepIndex,
CurrentStepIndex = this.CurrentStepIndex,
Pupil = new UserDto { UserId = this.PupilId, UserName = this.PupilName },
Tutors = this.GetTutors(this.CourseId),
Tutor = tutorName == null ? null : new UserDto { UserName = this.TutorName, UserId = this.TutorId}
};
}
}
#region Entities
int courseId;
public int CourseId
{
get
{
if (courseId == 0) throw new ApplicationException("Invalid Course Id!");
return courseId;
}
set
{
if (value == 0) throw new ApplicationException("Invalid Course Id!");
try
{
Course = (from c in CoursesRepository.Query where c.CourseId == value select c).First();
Steps = Course.CourseSteps.ToList();
courseId = value;
}
catch {throw new ApplicationException("No Course found for Course Id: " + value);}
}
}
public Data.Course Course { get; private set; }
public int StepOrder { get; set; }
public List<Data.CourseStep> Steps { get; private set; }
public int ActiveStepIndex
{
get
{
if (PupilName == null)
{
throw new ApplicationException("Pupil not set!");
}
if (CourseId == 0)
{
throw new ApplicationException("Course not set!");
}
try
{
var x = (from uc in UserCoursesRepository.Query where (uc.IdCourse == CourseId) && (uc.UserName == PupilName) select uc).First();
return x.ActiveStepIndex;
}
catch { throw new ApplicationException("Could not get Active Step!"); }
}
}
#endregion
#region Users
string tutorName;
public string TutorName
{
get
{
if (tutorName == null) throw new ApplicationException("Invalid call to get Tutor Name [Null Tutor Name]!");
return tutorName;
}
set
{
tutorName = value;
TutorId = (Guid)Membership.GetUser(tutorName).ProviderUserKey;
}
}
public Guid TutorId { get; set; }
string pupilName;
public string PupilName
{
get { return pupilName; }
set
{
pupilName = value;
PupilId = (Guid)Membership.GetUser(pupilName).ProviderUserKey;
}
}
public Guid PupilId { get; set; }
#endregion
#region Utility Properties
public int CurrentStepIndex { get; set; }
public int StepCount
{
get
{
return Steps == null ? 0 : Steps.Count();
}
}
#endregion
#region Private Utilities
private List<UserDto> GetTutors(int CourseId)
{
return (from ct in CourseTutorsRepository.Query join u in UsersRepository.Query
on ct.TutorName equals u.UserName
where (ct.CourseId == courseId)
select new UserDto { UserName = ct.TutorName, UserId = u.UserId }).ToList();
}
#endregion
#region Repositories
private IRepository<Course> CoursesRepository
{
get;
set;
}
private IRepository<CourseStep> StepsRepository
{
get;
set;
}
private IRepository<StepLink> StepLinksRepository
{
get;
set;
}
private IRepository<UserCourse> UserCoursesRepository
{
get;
set;
}
private IRepository<CourseTutor> CourseTutorsRepository
{
get;
set;
}
private IRepository<User> UsersRepository
{
get;
set;
}
#endregion
#endregion
}
}
May not be everyone's choice, but hey, it works for me... AND (more importantly) my clients and their users.
Edit
As requested in the comment below, the Repository that I use:
namespace ES.eLearning.Domain
{
public class SqlRepository<T> : IRepository<T> where T : class
{
DataContext db;
public SqlRepository(DataContext db)
{
this.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 Attach(T entity)
{
db.GetTable<T>().Attach(entity);
}
public void Save()
{
db.SubmitChanges();
}
#endregion
}
}
And the IRepository Interface:
namespace Wingspan.Web.Mvc
{
public interface IRepository<TEntity> where TEntity : class
{
List<TEntity> FetchAll();
IQueryable<TEntity> Query {get;}
void Add(TEntity entity);
void Delete(TEntity entity);
void Attach(TEntity entity);
void Save();
}
}
This should help you getting started. There are a lot of tutorials and videos available; for example:
Understanding Models, Views and Controllers
The ASP.NET MVC 2.0 basics and excellent introduction by Scott Hanselman. Personally one of my favorite speakers.
And also at www.asp.net; there are a few tutorials/examples to help you getting started. For example the Music Store sample
Unfortunately, I'm not so familiar with EF4/Repository pattern. But here's a blogpost about this pattern.
1) I would say that the repository pattern is the most widely used, then there is inversion of controll too.
2) I can't really point out the benefits with using a repository for entity framework other than that the controller should not know about how to acces data other then asking a repository. This makes it easy to switch it out sometime.
You can also eager load the data to make sure that the view don't call the database in every iteration of a foreach, for example a collection of users to display data from a child entity. You can probly do this anyway, but I feel that the repository is the right place to do it.
3) I can't tell you about the concept in a more in depth way, but I can tell some about viewmodels. In my opinion you should only use viewmodels if there is anything more then one entity you want to send to the view, for example a list of countries. You can alo use a viewmodel to "flatten" out very complex objects.
I would defiantly say the repository pattern is used a lot. This pattern can be used with Dependency Injection. Using Dependency Injection makes Unit Testing a breeze because you can snap different repositories to an abstract repoistory. Check out http://ninject.org/ for a simple to use Dependecy injector for .NET.
View Models should hold display data and transfer that data from the controller to the view. If you want to edit and display customer info, take a look at this

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