Core - Design-time Model Editor does not take Entity Framework class metadata into account

In XAF applications based on Entity Framework, the Types Info Subsystem needs an instance of the ObjectContext or DbContext class to retrieve complete information about business classes and their properties. Since there is no common way to create a context instance at design time, the Application Model shown in the design-time Model Editor may differ from the model generated at runtime.

To address this issue, we've provided the capability to specify the design-time context as follows:

1. Create an ObjectContextTypesInfoInitializerBase or DbContextTypesInfoInitializerBase descendant and override the ObjectContextTypesInfoInitializerBase.CreateObjectContext or DbContextTypesInfoInitializerBase.CreateDbContext method, respectively.
2. Decorate your context class with the TypesInfoInitializer attribute and specify the type of your Types Info Initializer class.
3. Add a default constructor to your DbContext class descendant.
   The following code demonstrates how this approach is used in the EF Demo Code First and Model First projects.
   Code First:

C#
using System.Data.Entity.Infrastructure;  
using DevExpress.ExpressApp.Design;  
using DevExpress.ExpressApp.EF.DesignTime;  

namespace EFDemo.Module.Data {  
    public class EFDemoDbContextInitializer : DbContextTypesInfoInitializerBase {  
        protected override DbContext CreateDbContext() {  
           DbContextInfo contextInfo = new DbContextInfo(typeof(EFDemoDbContext), new DbProviderInfo(providerInvariantName: "System.Data.SqlClient", providerManifestToken: "2008"));  
           return contextInfo.CreateInstance();  
        }  
    }  

    [TypesInfoInitializer(typeof(EFDemoDbContextInitializer))]  
    public class EFDemoDbContext : DbContext {  
        public EFDemoDbContext(String connectionString) : base(connectionString) {  
        }  
        public EFDemoDbContext() {  
        }  
        ...  
    }  
}  

Model First:

C#
using DevExpress.ExpressApp.Design;  
using DevExpress.ExpressApp.EF.DesignTime;  
using System.Data.Entity.Core.EntityClient;  

namespace EFDemo.Module.Data {  
    public class EFDemoObjectContextInitializer : ObjectContextTypesInfoInitializerBase {  
        protected override ObjectContext CreateObjectContext() {  
            EntityConnectionStringBuilder efConnectionStringBuilder = new EntityConnectionStringBuilder();  
            efConnectionStringBuilder.Metadata = "res://*/Data.EFDemoModel.csdl|res://*/Data.EFDemoModel.ssdl|res://*/Data.EFDemoModel.msl";  
            efConnectionStringBuilder.Provider = "System.Data.SqlClient";  
            return new EFDemoObjectContext(efConnectionStringBuilder.ConnectionString);  
        }  
    }  

    [TypesInfoInitializer(typeof(EFDemoObjectContextInitializer))]  
    public partial class EFDemoObjectContext {  
        public EFDemoObjectContext(string connectionString) : base(connectionString, "EFDemoObjectContext")  
        {  
            this.ContextOptions.LazyLoadingEnabled = true;  
        }  
        ...  
    }  
}  

Note that after these changes the Model Editor might take longer to open because the full type metadata is generated.