[6.0] Codegeneration improvements

[Daniel-Svensson]

High level goals for code generation

• Works for server projects which targets .net6 (maybe even for netstandard2.0)
  • also works for .Net Framework (what is supported today)
  • Keeps support for clients running .net framework, netstandard2.0 and net core (net5.0+) (Support mixed server / client framework versions #274 )
• Works cross platform with "dotnet build"
  Fixed by ([CodeGen] Support net6+ on server #414)
• Support portable pdb (Support for Portable PDBs in server project #185)

A working sample can be found in Samples repo

Codegen remaining work

• Add test similar to CreateRiaClientFiles_ASPNET_AppDomain for net6 link
  • We want a test which verifies that Program.SetupAppConfig in codegeneration program works as expected
• Add dependencies from Tools and Tools.TextTemplate in T4.nuspec link
• Create ServerClassLibNet6 by copying ServerClassLib link
• Fix insecurity with Path.GetTempFile()
• Implement or take action on server codegen validation
• Support nullable reference types (it generates attributes on client which gives Compile errors).
  • see nullable attributes metadata which needs to be "reversed/decompiled" to corresponding c#/vb code
  • a good temporary solution could be to ignore properties in code gen
• Support "required" properties (it generates an attribute on client which gives Compile errors)
• Support other new property features (if any) that are implemented as attributes that are not allowed to be specified in code ("init" properties?)

New codegen exe todo's:

Program.cs

• // TODO: Remove dependency on MSBuild and then remove any PackageReferences to MSBuild and MSBuildLocator
  - This will require splitting "OpenRiaServices.Tools" into 2 separate projects, one with MSbuild tasks and one without (just code generation)

SharedCodeServiceParametersBinder.cs

• Change parameter names to match "default/recommended" names such as "--shared-source-files"
  This might make the binders redundant and maybe allows some further cleanup of the program
  // TODO:

• Change name of project (and exe) , from "Tools.CodeGen" to something else such as "Tools.Console"

[Daniel-Svensson]

@ehsangfl you might be interested in trying out https://www.nuget.org/packages/OpenRiaServices.Client.CodeGen/5.4.0-tags-v5-4-0-preview-1.1 it can generate code directly against aspnetcore projects.