Definition

MVC is a software pattern to implement your UI. It divides the application into three dependent parts to separate the internal architecture of information from the method in which data is presented to and accepted from the user.

The Turnkey WebApplication uses MVC for index and login pages. It defaults to AngularJS for all other pages. To get MVC on other pages, you must set the tagged value MVC=true on a ViewModel.

MVC works differently from Angular in several ways. The main differences are these:

1. Grid-row-clicks, in MVC select of row, is done if there are zero or many actions, but if there is 1 action (defined in ViewModel) this action is executed on row click
2. MVC never shows a popup menu of multiple actions as Angular does

How to Build MVC Apps With MDrivenFramework

• MVC_Generated_ViewModel_UI_in_MDrivenFramework
• Comboboxes_in_MVC_from_model_driven_ViewModel
• MVC_View_Model_handling
• Getting_started_template_for_MDriven_MVC

New MVC Notes Autumn 2021

New Nuget packages for .net5 and .netStandard are published on Nuget and named MDriven.*

To get a package into an EcoSpace by code, add an attribute to EcoSpace like [EcoSpacePackage(typeof(Package1Package))]

To get binding a Codegen ViewModel to work, do this:

public IActionResult View([ModelBinder(typeof(VMClassBinder))] SampleViewModel value)
{
  return View("View");
}

To suppress the bogus validation done on VMClass, do this:

var mvc = services.AddMvc(options =>
{
  options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(VMClass)));
}); // to avoid validation of the complete world by following VMClass refs

To enable your page to roundtrip truly stateless, you need to know the ViewModel name and Root object ID on postback. Add these hidden fields in your form:

<input asp-for="ThisAsExternalId" hidden />
<input asp-for="ViewModelClass.ViewModel.Name" hidden/>

To use Runtime-generated Razor files from ViewModel, try this (see comments on why each row is added and choose wisely):

public class Startup
  {
    public Startup(IWebHostEnvironment env, IConfiguration configuration) //added to inject the IWebHostEnvironment, needed for files
    {
      _HostingEnvironment = env;
      Configuration = configuration;
    }

    private IWebHostEnvironment _HostingEnvironment;


    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.AddControllersWithViews();
      services.AddMemoryCache(); // to hold shelved ecospaces
      var mvc = services.AddMvc(options =>
      { 
        options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(VMClass))); // to avoid validation of the complete world by following VMClass refs
      }); 
      mvc.AddSessionStateTempDataProvider();
      services.AddSession(); // To hold selection etc during roundtrip

      services.Configure<MvcRazorRuntimeCompilationOptions>(options => {   // Needed to generate Razor for ViewModels
        options.FileProviders.Clear();
        options.FileProviders.Add(new MDrivenMVCCoreFileProvider(this._HostingEnvironment.ContentRootFileProvider, Directory.GetCurrentDirectory()));
      });

      services.AddRazorPages().AddRazorRuntimeCompilation(); //without AddRazorRuntimeCompilation our fileProvider is not called;

    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
      if (env.IsDevelopment())
      {
        app.UseDeveloperExceptionPage();
      }
      else
      {
        app.UseExceptionHandler("/Home/Error");
        // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
        app.UseHsts();
      }
      app.UseHttpsRedirection();
      app.UseStaticFiles();
      app.UseSession(); // to hold vm vars during MVC roundtrip

      app.UseRouting();

      app.UseAuthorization();



      app.UseEndpoints(endpoints =>
      {
        endpoints.MapControllerRoute(
                  name: "default",
                  pattern: "{controller=Home}/{action=Index}/{id?}");
      });
    }
  }

Setup EcoSpace and add model package references in .net5 like this:

namespace ClassLibrary6
{
  [EcoSpace]
  [UmlTaggedValue("Eco.InitializeNullableStringsToNull", "true")]
  [UmlTaggedValue("Eco.GenerateMultiplicityConstraints", "true")]
  [EcoSpacePackage(typeof(Package1Package))] // Add packages this way
  public partial class EcoSpace1 : Eco.Handles.DefaultEcoSpace
  {

    #region Eco Managed code
    private static ITypeSystemService typeSystemProvider;
    #endregion Eco Managed code

    public EcoSpace1() : base()
    {
      this.PersistenceMapper = new PersistenceMapperXml() { FileName = @"c:\temp\MVCTempData.xml" }; // simple setup during dev
    }

....

The example for download: File:2021MVCNet5.zip

Video discussing the example: https://youtu.be/UAA4_9fRNbA