Add @code directive support for Blazor

[ajaybhargavb]

Fixes dotnet/aspnetcore#6361

• Added @code directive that has the exact behavior as @functions
• Conditionally adding the directive only for Blazor
• Updated tests
• Verified it works in VS with the correct directive completion

Note:

• I didn't remove @functions directive support in Blazor.
• There might be weird problems if people use both functions and code in the same file. Should we add any restrictions/warnings here?

[NTaylorMullen]

Oo fancy. I have mixed feelings about having @code and @functions simultaneously available in component files but I think overall it's a good option to have so we're not completely different from classic Razor.

[NTaylorMullen]

• There might be weird problems if people use both functions and code in the same file. Should we add any restrictions/warnings here?

What sort of problems?

[ajaybhargavb]

What sort of problems?

Hello World
@functions { // Some code 1 }
@code { // Some code 2 }
@functions { // Some code 3 }

assuming functions directive pass runs first followed by code directive pass the above will be transformed into,

- Namespace
  - class
    - method
    - // Some code 1
    - // Some code 3
    - // Some code 2

Note the change in the ordering. This could potentially cause problems.
But I know this is an implementation details and a weird corner case. But my question was mostly whether we should even support the above scenario.

[NTaylorMullen]

I could see that being an issue for extremely large Razor documents and to me what makes it a corner case is the intermingling of functions and code. My bet is that most people will either use functions or they'll use code, super rarely both.

So ya, I agree with you that it's a weird corner case. Assuming it's a minor amount of work to implement your idea of adding warnings/restrictions. Which would you do?

[ajaybhargavb]

My bet is that most people will either use functions or they'll use code, super rarely both.

Exactly. Which is why I was wondering if we should enforce that in some way.

Assuming it's a minor amount of work to implement your idea of adding warnings/restrictions. Which would you do?

I think the easiest thing to do to avoid this completely is to merge functions and code directive passes into one.

[NTaylorMullen]

I think the easiest thing to do to avoid this completely is to merge functions and code directive passes into one.

Sounds fine to me. Would keep the logic consistent amongst the two yet still give us opportunities to diverge the functionality in the future if we want. Only thing to watch out for is we'd need to support users registering just one of the directives (or both) manually so we'd need to be sure that scenario works.

[ajaybhargavb]

🆙 📅

[NTaylorMullen]

Name this CodeDirective and the Register below as RegisterForComponents

[ajaybhargavb]

I'm just following the same pattern as other component directives.

[NTaylorMullen]

Ah I see, didn't realize we did that. Leave for now then, something we should revisit for all of the component like directives before RTM

[NTaylorMullen]

👏