Does Alamofire support JSON structured as an ordered list of values? Parameters are [String: Any], only complying to collections of name/value pairs

Question

http://json.org/ defines that JSON is built on two structures:

A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.
An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence.

I couldn't find a way to make Alamofire work on a post request where the parameters are [Any], which is the format required by the endpoint I'm consuming.

The error message is actualy a bit deceiving because it states "Extra argument in 'method' call" while performing a Alamofire.request but the actual problem is that parameters value is non-conforming.

I don't think you can just send [Any] type of parameters. You need to make a key value pair of [String: Any]. So that value can be identified by a Key at the server side. — Aditya, Jul 05 '19 at 05:24
@Aditya The thing is the server side wasn`t expecting a key value pair, but instead an ordered list of values. Instead of { "numbers": [1,2,3,4] } the server requires [1,2,3,4] which is also a valid json. — joycehf, Jul 06 '19 at 11:15

score 0 · Accepted Answer · answered Jul 05 '19 at 05:36

The parameter by the name of parameters in Alamofire expects [String: Any]. If you want to send an Array through Alamofire, you can define custom ParameterEncoding like this

struct CustomEncoding: ParameterEncoding {
    var _httpBody: Data?
    func encode(_ urlRequest: Alamofire.URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        var request = try URLEncoding().encode(urlRequest, with: parameters)
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpBody = _httpBody
        return request
    }
}

Then use it like this

let body = ... // 'Array' converted to 'Data'
Alamofire.request(...,
                  method: ...,
                  parameters: [:],
                  encoding: CustomEncoding(_httpBody: body),
                  headers: ...)

Does Alamofire support JSON structured as an ordered list of values? Parameters are [String: Any], only complying to collections of name/value pairs

1 Answers1