Return two values mapped from a content response to completion handler

Question

This return is sending back a single string, the accessToken from the ContentResponse:

return body.encodeResponse(for: request)
     .map { $0.body.buffer }
     .flatMap { buffer in
             return request.client.post(url, headers: self.callbackHeaders) { $0.body = buffer }
     }.flatMapThrowing { response in
             return try response.content.get(ContentResponse.self)
     }.map { $0.accessToken }

which is being received in the completion handler here:

return try self.fetchToken(from: request).flatMap { accessToken in

How can I send back two strings - both the accessToken and the refreshToken from the ContentResponse?

Thanks so much for any help in how to structure this!

Answer 1

You could define and use a struct to return, but for one-off cases like this, I usually just go with a tuple with named members:

return body.encodeResponse(for: request)
     .map { $0.body.buffer }
     .flatMap { buffer in
             return request.client.post(url, headers: self.callbackHeaders) { $0.body = buffer }
     }.flatMapThrowing { response in
             return try response.content.get(ContentResponse.self)
     }.map { (accessToken: $0.accessToken, refreshToken: $0.refreshToken) } // <<- This is changed line

That will result in a return type of [(accessToken: String, refreshToken: String)] instead of [String], so the return type of fetchToken(from:) will have to be changed to match.

Then the code where you call it looks like this:

return try self.fetchToken(from: request).flatMap { tokens in // <<- renamed to indicate it contains more than one value
   /* 
    refer to tokens.accessToken and tokens.refreshToken in whatever 
    code goes here 
   */
   ...
}