what are convintioal routing order in asp.net core web application

Conventional routing in ASP.NET Core is a way to define routes that map URL patterns to controllers and actions. The key points from the sentence are:

1. Order-Dependent: The order in which routes are defined matters. Routes defined earlier have higher priority.
2. Automatic Order Assignment: When you use methods like MapControllerRoute, MapDefaultControllerRoute, and MapAreaControllerRoute, they are assigned an order based on the sequence they are added.
3. Specificity: Routes with areas should be placed earlier because they are more specific.
4. Greedy Routes: Routes with catch-all parameters (like {*article}) can match more URLs than intended, so they should be placed later to avoid unintended matches.

Code Example

Here’s an example to illustrate these points:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        // More specific route with area
        endpoints.MapAreaControllerRoute(
            name: "Admin",
            areaName: "Admin",
            pattern: "Admin/{controller=Home}/{action=Index}/{id?}");

        // Default route
        endpoints.MapDefaultControllerRoute();

        // Greedy route with catch-all parameter
        endpoints.MapControllerRoute(
            name: "greedy",
            pattern: "{*article}",
            defaults: new { controller = "Article", action = "Index" });
    });
}

Breakdown

1. Admin Area Route:

   endpoints.MapAreaControllerRoute(
       name: "Admin",
       areaName: "Admin",
       pattern: "Admin/{controller=Home}/{action=Index}/{id?}");
   

   This route is specific to the “Admin” area and is placed first because it is more specific.

2. Default Route:

   endpoints.MapDefaultControllerRoute();
   

   This is the default route pattern {controller=Home}/{action=Index}/{id?}. It is less specific than the area route but more specific than the greedy route.

3. Greedy Route:

   endpoints.MapControllerRoute(
       name: "greedy",
       pattern: "{*article}",
       defaults: new { controller = "Article", action = "Index" });
   

   This route uses a catch-all parameter {*article} and is placed last to avoid it matching URLs that should be handled by the more specific routes defined earlier.

By following this order, you ensure that the most specific routes are matched first, and the greedy routes are matched only if no other routes apply. This helps prevent unintended matches and ensures that your routing logic works as expected.

Thanks