WebAssembly SDK - what is the replacement for `<WasmExtraFilesToDeploy>`?

[JakeYallop]

I have additional files that are produced at build time, so they cannot exist in the /wwwroot folder, that I want to output with the rest of my app. Non-WebAssembly SDK projects could use for this - what can be used for WebAssembly SDK projects?

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.

[JakeYallop]

Linking a workaround I've document in #117900.

Just adding the files as <Content /> without any special handing does not work if those files are not within the wwwroot folder (and if they are in there, they'll be included anyway). Any Content files not in wwwroot are filtered out by the ResolveProjectStaticWebAssets target.

Instead, what I had to do was create a target that ran before AssignTargetPaths - this is the task that resolves <Content />, add them specifically at that point:

 <Target Name="_AddContent" BeforeTargets="AssignTargetPaths">
    <ItemGroup>
      <Content Include="MyContent.json">
        <! -- content configuration etc. -->
      </Content>
    </ItemGroup>
  </Target>

[maraf]

Is it problematic to generate the files into wwwroot and just gitinore them?

cc @javiercn

[JakeYallop]

Technically, that would work - however, I think its very surprising if I have

    <ItemGroup>
      <Content Include="package.json">
        <CopyToOutputDirectory>Always</CopyToOutputDirectory>
        <CopyToPublishDirectory>Always</CopyToPublishDirectory>
      </Content>
    </ItemGroup>

in my csproj, and it doesn't get copied the output folder.

And, I'd now have to maintain that gitignore. Ignoring wwwroot/ completely doesn't seem like a good solution (as users may have other files in wwwroot that they want to commit, although it would work for my specific case).

It would be nicer to find a solution that is more intuitive and easier to document than the workaround needed above (and of course, that workaround is not gauranteed to continue to work if the task execution order changes between updates), whether that's getting <Content> to work, or using an alternative property,

[maraf]

The general problem is that the csproj contains all sorts of files. Some of them are C# that should be passed to compiler and not copied to the output, some are server side configuration files, like appSettings.json which may contain secrets. They are all part of <Content /> collection as well. So there needs to be a pattern for expressing files that are meant to be accessible from the browser. In the proprietary runtime SDK (WasmAppBuilder), it was the WasmExtraFilesToDeploy. AspNetCore (and Blazor and now the more general WasmSDK) has convention of wwwroot. All Content items marked with CopyToOutput are copied to output, but not to the output/wwwroot, because they are not treated as browser-accessible files.

The gitignore can contain various patterns, so that wwwroot can contain user files as well as generated files. Anyway I understand the inconvenience.

@javiercn might have more context about generated files accessible from the server.

[JakeYallop]

The general problem is that the csproj contains all sorts of files.

Right - its totally fine if we don't end up using Content, as long as there is some kind of solution. Trying to copy over the files manually is a non-starter, when taking into account different output paths for build vs publish etc. If that solution is a custom MSBuild property, similar to WasmExtraFilesToDeploy, great, if not, then be nice to document whatever the solution might be - if that's "output the files into wwwroot", then that's fine.