openai-aspnet-core/references/ui-mvc.md

MVC

Primary docs: - https://learn.microsoft.com/aspnet/core/mvc/overview - https://learn.microsoft.com/aspnet/core/mvc/controllers/ - https://learn.microsoft.com/aspnet/core/mvc/views/

Choose MVC When Actions And Views Matter

Prefer MVC when the application benefits from explicit controllers, action-based routing, filters, view models, and a strong separation between orchestration and presentation.

This is often the right fit for:

• large server-rendered sites
• applications with many cross-cutting filters or action conventions
• applications that mix views and APIs in the same controller layer
• teams already organized around controllers and views

Core Shape

Enable MVC with views using:

• builder.Services.AddControllersWithViews();
• app.MapControllerRoute(...)

Keep views focused on presentation. Keep controllers focused on HTTP orchestration. Put business rules in services.

Controller Guidance

• Derive from Controller when the controller returns views
• Keep actions small and explicit
• Use model binding and validation instead of manual request parsing
• Return view models, not EF entities, to views
• Use POST-Redirect-GET for form submissions

View Guidance

• Use layouts, partial views, and Tag Helpers to keep markup consistent
• Keep complex display logic out of Razor markup when it becomes hard to follow
• Use strongly typed view models
• Avoid coupling views directly to persistence models

Structure And Scale

• Use areas for large bounded sections such as Admin or BackOffice
• Keep route conventions explicit
• Apply filters when behavior truly belongs at the MVC layer
• Avoid giant god controllers; split by cohesive feature or resource

Choosing MVC Over Razor Pages

Prefer MVC over Razor Pages when:

• multiple related actions share controller-level behavior
• handler-level authorization or action filters matter
• URL and action design are more natural than page-file routing