🛠 Custom T4 Template Setup for Devart EF Core with DevExpress XAF

✅ Requirements

Before you start, make sure you have the following installed:

• DevExpress XAF (eXpressApp Framework) (25.1.x)

  • DevExpress XAF

• Devart Entity Developer (Edition for Entity Framework) (7.3.235)

  • Devart Entity Developer

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📁 Template Location

There are two files:

• .tmpl (T4 template file)
• .xml (metadata)

Copy the two files into the folder located at:

C:\Program Files (x86)\Common Files\Devart\EntityDeveloper\Shared Templates

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🔧 Step-by-Step Instructions

1. Create an app using the XAF wizard.

2. Save, close, and reopen the project.

3. Create a new Devart EF Core model file.

   • Right-click > Add > New Item
   • Choose: Data or ASP.NET Core > Data
   • Select: Devart EF Core Model

4. Select "Database First" approach.

5. Configure the SQL Server connection.

   • Choose server and database.
   • In Advanced, set the following:

     MultipleActiveResultSets=True
     Encrypt=True
     TrustServerCertificate=True
     

6. Generate model from database.

   • Select the desired tables or select them later.

7. Leave the default settings

8. Configure context and namespace:

   • Namespace context/entities: <YourNameProject>.Module.BusinessObjects
   • Context Class Name: <YourNameProject>EFCoreDbContext

9. Add the custom template:

   • Click the first "Add Template" button
   • From Shared, choose: EF Core XAF
   • Remove any other existing template

10. Click "Finish" to complete the setup.

11. Change code in XAF wizard

//[TypesInfoInitializer(typeof(TelemacoContextInitializer))]
public partial class TelemacoEFCoreDbContext : DbContext {
    //public TelemacoEFCoreDbContext(DbContextOptions<TelemacoEFCoreDbContext> options) : base(options) {
    //}
    //public DbSet<ModuleInfo> ModulesInfo { get; set; }

    partial void OnModelCreatingPartial(ModelBuilder modelBuilder)
    {
        modelBuilder.UseDeferredDeletion(this);
        modelBuilder.UseOptimisticLock();
        modelBuilder.SetOneToManyAssociationDeleteBehavior(DeleteBehavior.SetNull, DeleteBehavior.Cascade);
        modelBuilder.HasChangeTrackingStrategy(ChangeTrackingStrategy.ChangingAndChangedNotificationsWithOriginalValues);
        modelBuilder.UsePropertyAccessMode(PropertyAccessMode.PreferFieldDuringConstruction);
    }
    
}

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✅ Result

Your Devart EF Core model will now generate code that’s fully compatible with DevExpress XAF using the customized T4 template.