Allow dynamic headers

[LucaFilitz]

Hello,
when you create a upload link, you can only set the headers once.
This is a problem when you refresh your authentication token.

Apollo allows to pass a function to the connecitonParams so that every time a request is made the token is fetched. This is better.

What is possible:
createUploadLink({ uri: "SOME URI", headers: { Authorization: "Bearer " + get(token) } })

What I need:
createUploadLink({ uri: "SOME URI", headers: () => { return { Authorization: "Bearer " + get(token) } } })

Currently, when I do this no headers are passed.

Could you fix this?
Kind Regards
Luca

[jaydenseric]

Is that a new-ish thing in Apollo that you can do that?

For now, you should be able to create the headers each request via a custom Apollo Link:

https://www.apollographql.com/docs/react/networking/advanced-http-networking/#customizing-request-logic

[LucaFilitz]

I think it is kind of new. But not that new.
Oh, yes that is corretct I didn't think about adding a middleware.
Still, it would be nice to not need it :)
I might open a pull request if you don't mind.

[LucaFilitz]

It looks like
selectHttpOptionsAndBody (createUploadLink.js l. 118)
somehow validates the headers.
Therfor you'd have to rewrite that part/ create your own function.

To be honest I do not know what it does and do not want to touch it.

=> I will use the middleware for now.

[sashrika]

This worked for me.

const httpOptions = {
timeout: 15000,
uri: GRAPHQL_SERVER_V1,
};

const authMiddleware = setContext((operation, { headers }) => {
    return getCredentials().then(data => {
      return {
        headers: {
          ...headers,
          authorization: `Bearer ${data?.accessToken}` || null,
        }
      };
    });
  });
  

const singleLink = split(
    ({ query }) => {
        const definition = getMainDefinition(query);
        return (
            definition.kind === "OperationDefinition" &&
            definition.operation === "subscription"
        );
    },
    wssLink,
    split(
        operation => operation.getContext().hasUpload,
        from([authMiddleware, createUploadLink({ ...httpOptions, isExtractableFile: customIsExtractableFile })]),
        from([authMiddleware, httpLink])
    )
);