Problems Passing Model from Entity Framework

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Answer 1

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User1120430333 posted

Thanks for the response. I appreciate the learning experience and am really trying to take in all of the lessons. I'm struggling is a few spots including interfaces, why use them, when to use them, etc. I am able to access the DaoPatient GetAll() but can't seem to access IDaoPatient. I haven't figure out how to return either of these successfully to the controller and the view.

And about the above, you can access IDaoPatient by doing something like this.

var data = SomeClass( new IDaoPatient).GetSomeData().ToLIat()

The SomeClass exxpects the DoaPatient class/object to be DI into SomeClass' constructor so that it can be used by GetSomeData(). Of course a new IDaoPatierent is instancing DaoPatient.

The above can be done during a unit test to satisfy the requirement of SomeClass that expects DaoPatient is going to be injected into SomeClass.

. You see the constructor for AuthorController(IAuthorDM authorDM) is specifying that AuthorDM be injected into it and that' s how you do it by the class's Interface in the constrctor. The AuthorDM was instanced by the Core IoC, and it was DI into the class by the Core IoC . You see the Core IoC being configured to use the classes and their Interfaces.

Below that, a VB.NET MVC5 example using the Unity IoC that is registering the classes along with their Interfaces so that they can be DI into the solution when needed. One set is for the ASP.NET Identity classes and their interfaces as well that are controlled by the IoC

In the Windows forms MVC solution, by the way MVC started out on desktop solutions well before it got to the Web, you can see the Interface being used,

https://www.codeproject.com/Articles/383153/The-Model-View-Controller-MVC-Pattern-with-Csharp

using Microsoft.AspNetCore.Mvc;
using PublishingCompany.Models;

namespace PublishingCompany.Controllers
{
    public class AuthorController : Controller
    {
        private IAuthorDM adm;
        public AuthorController(IAuthorDM authorDM)
        {
            adm = authorDM;
        }

        public IActionResult Index()
        {
            return View(adm.GetAll());
        }

        public IActionResult Detail(int id = 0)
        {
            return id == 0 ? null : View(adm.Find(id));
        }

        public IActionResult Create()
        {
            return View(adm.Add());
        }

        [HttpPost]
        public ActionResult Create(AuthorVM.Author author, string submit)
        {
            if (submit == "Cancel") return RedirectToAction("Index");

            if (!ModelState.IsValid) return View(author);

            adm.Add(author);
            return RedirectToAction("Index");
        }
        
        public ActionResult Edit(int id = 0)
        {
            return id == 0 ? null : View(adm.Update(id));
        }
        
        [HttpPost]
        public ActionResult Edit(AuthorVM.Author author, string submit)
        {
            if (submit == "Cancel") return RedirectToAction("Index");
                        
            if (!ModelState.IsValid) return View(author);
                       
            adm.Update(author);
            return RedirectToAction("Index");
        }
        public IActionResult Delete(int id = 0)
        {
            if (id > 0) adm.Delete(id);

            return RedirectToAction("Index");
        }

        public ActionResult Cancel()
        {
            return RedirectToAction("Index", "Home");
        }
    }
}

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Serilog;
using ServiceLayer;
using PublishingCompany.Models;

namespace PublishingCompany
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
            Log.Logger = new LoggerConfiguration().ReadFrom.Configuration(configuration).CreateLogger();
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            //Domain Model
            services.AddTransient<IAuthorDM, AuthorDM>();
            services.AddTransient<IPayRollDM, PayRollDM>();
            services.AddTransient<IArticleDM, ArticleDM>();

            //ServiceLayer
            services.AddTransient<IAuthorSvc, AuthorSvc>();
            services.AddTransient<IPayRollSvc, PayRollSvc>();
            services.AddTransient<IArticleSvc, ArticleSvc>();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env,  ILoggerFactory loggerFactory)
        {
            loggerFactory.AddSerilog();

            app.UseExceptionHandler("/Home/Error");
            
            app.UseStaticFiles();
            app.UseCookiePolicy();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}

Imports System.Data.Entity
Imports Microsoft.AspNet.Identity
Imports Microsoft.AspNet.Identity.EntityFramework
Imports ProgMgmntVB.Controllers
Imports ProgMgmntVB.Models
Imports ProgMgmntVB.WebApi
Imports Unity
Imports Unity.Injection
Imports Unity.Lifetime
Imports Unity.Mvc5

Module ModuleUnity

    public class UnityConfig

        public shared sub RegisterComponents()

            dim container = new UnityContainer()

            container.RegisterType(Of IProjectModel, ProjectModel)() 
            container.RegisterType(Of ITaskModel, TaskModel)()
            container.RegisterType(Of IWebApi, WebApi.WebApi)()
            container.RegisterType(Of IModelHelper, ModelHelper)()

            'Idenity 

            container.RegisterType(Of DbContext, ApplicationDbContext)(new HierarchicalLifetimeManager())
            container.RegisterType(of UserManager(of ApplicationUser))(new HierarchicalLifetimeManager())
            container.RegisterType(of IUserStore(of ApplicationUser), UserStore(of ApplicationUser))(New HierarchicalLifetimeManager())
            container.RegisterType(of AccountController)(new InjectionConstructor())

            DependencyResolver.SetResolver(new UnityDependencyResolver(container))

        End sub
    
    End Class
End Module

Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM

Saturday, August 3, 2019 8:16 AM

Answer 2

0

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User475983607 posted

That clarifies some of my confusions. But why use this instead of simply implementing a class?

Interfaces are another tool in your toolbox. The construct is very common and a subject that I recommend taking the time to learn.

Below is a very common pattern where the a business logic class can accept any type that implements IBehavior.

    public class BusinessLogic
    {
        private readonly IBehavior _behavior;
        public BusinessLogic(IBehavior behavior)
        {
            _behavior = behavior;
        }

        public string Talk()
        {
            return _behavior.Talk();
        }
    }

Implementation.

        static void Main(string[] args)
        {
            BusinessLogic bl1 = new BusinessLogic(new Person());
            BusinessLogic bl2 = new BusinessLogic(new Dog());

            Console.WriteLine(bl1.Talk());
            Console.WriteLine(bl2.Talk());
        }

Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM

Saturday, August 3, 2019 12:52 PM

Answer 3