Set headers with nested key-value in Alamofire

Question

I'm trying to set the headers of an Alamofire 4 request where the headers have a key whose value is another key-value pair. The swift compiler is happy with my header variables but Alamofire won't take them.

This is what I have:

 let subHeader = [
  "some-key": "some-value",
  "another-oey": "another-value"
  ]

let headers : [String: Any] = [
  "some-header-key": "some-header-value",
  "subdata": [subHeader]
  ]

// Upload data                  
Alamofire.upload(data,
   to: uploadurl,
   method: .put,
   headers: headers)
   .validate()
   .response { response in
   // Handle response
 }

Answer 1

If you have a look at Alamofire's source, you can see HTTPHeaders is actually [String: String]. Basically, Alamofire expects [String: String] from you as headers.

What you can do is converting your subheader into String with NSJSONSerialization and pass it to Alamofire.

let dictData = try! JSONSerialization.data(withJSONObject: subheader)
let dictString = String(data: dictData, encoding: String.Encoding.utf8)!
print(dictString)
// Now use "dictString" instead of "subheader" in your "headers" dictionary

You can do error handling however you want, I used !s for simplicity.