BuildRenderTree does not get called in Preview 4

[DerekChasse]

Describe the bug

I've added a simple component which overrides BuildRenderTree and attempts to wrap ChildContent in a simple <div>. I've more complex logic in a real-world usage, but this simple test demonstrates the issue.

I'm wondering if this is related to the ix for #8192

To Reproduce

See reproducible demo here:
https://github.com/DerekChasse/BuildRenderTree

Index.razor has a <p> tag which should, as part of rendering the TestComponent, be wrapped in a <div> and that <div> should have a GUID identifier as a simple test of AddAttribute.

Expected behavior

I would expect that, as in preview 0.9.0 calls to the overridden BuildRenderTree be honored.

Screenshots

Additional context

There is also simple logging with Console.Writeline in the BaseIndex baseclass which was previously honored in and is no longer being called.

Visual Studio 16.1.0 Preview 2.0
dotnet 3.0.100-preview4-011223

[chrissainty]

@DerekChasse I've messaged you on Gitter as well but this looks to be an issue with your code.

You've overridden BuildRenderTree in a base class, TestComponentBase.cs, which is inherited by TestComponent.razor but you've also specified markup in TestComponent.razor file.

I believe the razor code will override your code in BuildRenderTree hence you are not seeing the expected outcome.

Generally, I would not write code in BuildRenderTree and would try and stick to razor.

[rynowak]

The explanation from @chrissainty is correct. Generated Razor code will replace override BuildRenderTree() and will not call call base.BuildRenderTree(). This is the intended behavior, we want to make it possible to subclass a component and totally replace its markup.