gumbarros / CoreWebForms

WebForms on ASP.NET Core

The goal of this project is to explore building some of the basic building blocks of the WebForms on ASP.NET Core. This will isolate out the actual components needed to build a functional page.

Supported so far:

• System.Web.IHttpHandler
• System.Web.UI.Page
• System.Web.UI.HtmlTextWriter
• System.Web.UI.HtmlControls.*
• System.Web.UI.WebControls.*
• System.Web.Routing.*
• Master pages
• Compilation of aspx pages (both VB and C#)
• Binary compatibility (via the WebForms.SystemWebShim package) - limited support; needs testing

What is NOT supported:

• Designer support
• System.Web hosting model
• System.Web membership model
• Any System.Web concept not called out as in scope

This will make use of Microsoft.AspNetCore.SystemWebAdapters to provide the System.Web.HttpContext that is at the core of the WebForms pipeline.

Packages

• WebForms - Contains the majority of the page/control/etc methods required for WebForms
• WebForms.Compiler - Build time compiler that will generate a .dll for each page in the project. This includes a Roslyn code generator that can generate a strongly-type file to include the compiled assemblies that will remove the need for runtime reflection to load them.
• WebForms.Compiler.Dynamic - Run time compiler that will allow for updating aspx at run time and generating a new in-memory assembly
• WebForms.HttpHandler - Contains IHttpHandler and related helpers to enable hooking them up to ASP.NET Core
• WebForms.Routing - Contains APIs from the System.Web.Routing namespace
• WebForms.Extensions - Contains APIs from the System.Web.Extensions namespace
• WebForms.SystemWebShim - A package with a System.Web.dll assembly that will type forward to the new locations. This is build for .NET 6+ and would help with controls/assemblies/etc that are compiled and cannot be recompiled for some reason. If they use members/types not supported, they will throw at runtime, but can be a helpful step in migrating old projects (see the TypeDumper tool to regenerate the available types for the shim)

Get Started

1. Add a nuget.config or update yours to have the ci feed:

   <?xml version="1.0" encoding="utf-8"?>
   <configuration>
     <packageSources>
       <!--To inherit the global NuGet package sources remove the <clear/> line below -->
       <clear />
       <add key="nuget" value="https://api.nuget.org/v3/index.json" />
       <add key="webforms" value="https://webformsfeed.blob.core.windows.net/feed/index.json" />
     </packageSources>
   </configuration>

2. Add WebForms and WebForms.Compiler to your project

3. Add WebForms to your services (this automatically will add the System.Web adapters - this can be configured independently if needed)

   builder.Services.AddWebForms()
       .AddCompiledPages();
   
   builder.Services.AddSession();
   builder.Services.AddDistributedMemoryCache();

4. Add the System.Web middleware and map the webforms pages:

   ...
   app.UseSession();
   app.UseSystemWebAdapters();
   ...
   app.MapWebForms();

5. Add any .aspx or .aspx.cs/.aspx.vb files to your project. They should be served up as expected when you run.

Alternate

There is a dynamic compilation method that can be enabled by doing the following (continued from the above sample):

1. Add WebForms.Compiler.Dynamic and WebForms.Compiler

2. Add <EnableRuntimeAspxCompilation>true</EnableRuntimeAspxCompilation> to a property group in the project file

3. Add dynamic compilation to the services:

   builder.Services.AddWebForms()
       .AddDynamicPages();

Design docs

Please see the design docs to see the designs and plans for how this are expected to work.