[ASPNETCORE] multiple tags for a method generates multiple controllers

[magnayn]

Description

Multiple tags create multiple server endpoints

openapi-generator version

4.0.0-beta3

OpenAPI declaration file content or url

This is more a query (is there not a ML/community for this sort of thing?).

I've declared tags in the OpenAPI specification, to thematically collect API calls around various use-cases.

Thus API methods may have several tags. This is very useful in documentation generation.

But when aspnetcore generation occurs, you get a controller per tag - which doesn't seem right at all - not least of which the URL is identical in both.

There seems to be an assumption that a method has only one tag (maybe?) for the server end.

There doesn't seem to be a nice way to split up big APIs in OpenAPI that works nicely. Unless I'm missing something..

[nmuesch]

I'm currently seeing this on other generated languages as well. I think this is something in the core code as opposed to each template. It would be nice to have a way to allow multiple tags in the openapi spec.

[wing328]

Are you suggesting only the first tag should be considered if multiple tags are present?

[Sshnyari]

I had the same issue, but with a client generator. with typescript-redux-query we have the same methods duplicated among different files, thus the generated code have compile errors.

@wing328 considering only the first tag means that there is a primary tag, and that defeats the purpose of tags.

Is there another way to regroup paths in code ? (by path start perhaps)

[InfoSec812]

@Sshnyari According to the docs for OpenAPI, tags are there to help group related operations and all of the examples show a single tag on each operation/endpoint. Multiple tags also will not work correctly in SwaggerUI. Could you explain the use-case in which you would desire multiple tags on a single operation?

[magnayn]

I'm not sure I can be much clearer than the original ticket.

When you have a large-ish API, I want to be able to tag methods around themes. That's exactly the capability as described in the OpenAPI documentation, and is useful to help users reduce a big API surface area down to just the calls likely needed.

This is helpful in the documentation generated, as you can say "these are tagged to relate to this use-case". UIs do support this and show the top-level groupings that you define based on those tags. I.E: my method may be included in more than one "section" of the documentation. I don't know what you mean by the claim that it doesn't work in SwaggerUI - it works perfectly well in editor.swagger.io - define a second tag, add it to some methods and it works exactly as I'd expect.

At the end of the day, OpenAPI allows multiple tags per method (which is kind of the point, no?). But the code generated simply doesn't work as it tries to implement the same path multiple times over.

[InfoSec812]

I guess I'm curious what you would want this to look like in the generated code. How does the generator decide which controller the operation should be attached to. If we do it based on path, that also has issues which I have experienced in the past.