what if i used the MaPController() with view()?

Hi Mina,

If you use only attribute routing in a .NET application and avoid conventional routing, while also using the MapController() method, there are a few key points to consider:

1. Attribute Routing in API vs MVC:

• Attribute routing was originally introduced for Web APIs, but it works for MVC controllers as well, even when they return views. You can use [Route], [HttpGet], [HttpPost], and other HTTP method attributes in MVC controllers, and they will work just fine.
• The confusion might come from the fact that MapControllerRoute() (conventional routing) is typically used to map views in traditional MVC applications, while MapControllers() is commonly used with APIs.

2. What Happens When Using MapControllers() in MVC:

• MapControllers() maps controllers via attribute routing only, without requiring conventional routing definitions. However, this approach was primarily designed for APIs and does not provide out-of-the-box support for returning views.
• If you use MapControllers() in a typical MVC app that serves views, the routing still works, but you must rely exclusively on attribute routing. Any action method that returns a view (e.g., return View()) will still work as long as it is correctly mapped via attributes.
• You can still return views with attribute routing, but you will lose the automatic controller-action-based route matching that conventional routing provides.

3. Benefits and Drawbacks:

• Benefits of Attribute Routing Only:

  • Fine-grained control: You have complete control over the URLs for each action method.
  • Cleaner URLs: You can specify custom routes without worrying about the pattern defined by conventional routes.
  • Easier for APIs: If you are building a RESTful API alongside MVC, attribute routing can simplify things since it is naturally more explicit.

• Drawbacks of Attribute Routing Only:

  • Redundancy: You have to explicitly define routes for every action, which can become verbose if many of your actions follow the same URL pattern.
  • No fallback: You lose the benefit of automatic route matching for your views. Without a conventional route as a fallback, any missing route definition will lead to errors.
  • Maintenance: As your application grows, maintaining and managing all the attribute routes can become more cumbersome.

4. Best Practice:

• It’s often recommended to use a combination of both conventional routing and attribute routing:
  • Use conventional routing to handle most of your standard views (like /Controller/Action/Id pattern), as it provides a simple and scalable solution.
  • Use attribute routing when you need more control, especially for more customized or RESTful routes.

Suggested Approach:

• If your app heavily relies on MVC views, it’s better to:
  1. Use both conventional routing and attribute routing.
  2. Map controllers with views using MapControllerRoute().
  3. Use attribute routing where necessary, such as in API controllers or specific MVC actions that need custom routing.

Example Setup with Both:

app.UseEndpoints(endpoints =>
{
    // Conventional routing for views
    endpoints.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");
    
    // Attribute routing for controllers with API-like behavior
    endpoints.MapControllers(); // Only those with [Route] attributes will be mapped
});

This way, you get the flexibility of custom attribute routing while keeping conventional routing for views, which simplifies maintenance and avoids unnecessary route definitions.