ASP.Net MVC Core: setup view area location path

Question

i read a article which discuss how to setup custom path for view

http://www.c-sharpcorner.com/article/expanding-razor-view-location-and-sub-areas-in-asp-net-core/

one area is not clear regarding routing code setup.

app.UseMvc(routes =>

{
routes.MapRoute(
name: "subAreaRoute",
template: "{area:exists}/{subarea:exists}/{controller=Home}/{action=Index}/{id?}");
routes.MapRoute(
name: "areaRoute",
template: "{area:exists}/{controller=Home}/{action=Index}/{id?}");
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});

what is the meaning of {area:exists} code ?

what it does ? what it is checking ?

please help me to understand this. thanks

Rajeesh Menoth · Answer

Hi Please refer this : https://stackoverflow.com/questions/32294527/where-is-the-documentation-for-the-exists-routing-constraint-in-asp-net-mvc5

tri_inn · Answer

i did not ask what is area rather i want to know what the below code mean {area:exists} what kind of expression is it ? what it does ?

Rajeesh Menoth · Answer

Hi Areas provide a way to partition a large ASP.NET Core MVC Web app into smaller functional groupings. An area is effectively an MVC structure inside an application. The [Area] attribute decorates controllers included in the area. It takes only one parameter the name of the area. Reference : https://stackoverflow.com/questions/27254771/using-areas-in-asp-net-5 https://docs.microsoft.com/en-us/aspnet/core/mvc/controllers/areas