[Breaking change]: Razor runtime compilation is obsolete #522
Description
Description
Razor runtime compilation is obsolete and is not recommended for production scenarios. For production scenarios, use the default build time compilation. For development scenarios, use Hot Reload instead.
Version
.NET 10 Preview 7
Previous behavior
Developers could use Razor runtime compilation to recompile .cshtml files while the application is running. This is useful for development time so you don't need to restart the application for changes to take affect.
We're now obsoleting this and recommending developers make use of Hot Reload which has the same effect for development time.
New behavior
Using the APIs listed below will produce a compiler warning with diagnostic ID ASPDEPR003:
warning ASPDEPR003: Razor runtime compilation is obsolete and is not recommended for production scenarios. For production scenarios, use the default build time compilation. For development scenarios, use Hot Reload instead. For more information, visit https://aka.ms/aspnet/deprecate/003.
Type of breaking change
- Binary incompatible: Existing binaries may encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.
- Source incompatible: When recompiled using the new SDK or component or to target the new runtime, existing source code may require source changes to compile successfully.
- Behavioral change: Existing binaries may behave differently at run time.
Reason for change
Razor Runtime compilation has been replaced by Hot Reload which has been the recommended approach for a few years now. We're making it clearer that Razor Runtime compilation is not getting support for new features and should no longer be used.
Recommended action
Remove calls to .AddRazorRuntimeCompilation() and use Hot Reload.
Affected APIs
Microsoft.AspNetCore.Mvc.ApplicationParts.AssemblyPartExtensions
Microsoft.Extensions.DependencyInjection.RazorRuntimeCompilationMvcBuilderExtensions.AddRazorRuntimeCompilation
Microsoft.Extensions.DependencyInjection.RazorRuntimeCompilationMvcCoreBuilderExtensions.AddRazorRuntimeCompilation
Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.FileProviderRazorProjectItem
Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.MvcRazorRuntimeCompilationOptions