array as params is not working with Alamofire - swift

Question

I have an API where I need to send data as object so there I pass data as below and it works fine.
["fname" : "First 1", "lname": "Last 1"]
But for one of the API, web developer need API as Array as below.
[["fname" : "First 1", "lname": "Last 1"]]
Any idea what is going wrong?
Below is the code I have
parameters = ..... data that I passed as [String : Any] // e.x. ["fname" : "First 1", "lname": "Last 1"]
var finalWebParams : Any
var webParams2 : [[String : Any]] = [[String : Any]]()
if (webserviceFor=="array") {
webParams = parameters as [String:Any]
webParams2.append(webParams)
}
if (webserviceFor=="array") {
finalWebParams = webParams2
} else {
finalWebParams = webParams
}
print("finalWebParams==\(finalWebParams)")
request(url, method: webMethod, parameters: finalWebParams as? Parameters, encoding: myEncoding, headers: headers)
For print I get result as below, means I am passing correct data however I get 500 error.
[["fname" : "First 1", "lname": "Last 1"]]
Any idea what I am doing wrong?
Edit 1
below is the model that web developer need
[
{
"fname" : "First 1",
"lname" : "Last 1"
}
]

Answer 1

The answer is I need to add ArrayEncoding as below.
var finalWebParams : [String : Any]
var webParams2 : [[String : Any]] = [[String : Any]]()
if (webserviceFor=="array") {
webParams = parameters as [String:Any]
webParams2.append(webParams)
}
if (webserviceFor=="array") {
finalWebParams = webParams2.asParameters()
} else {
finalWebParams = webParams
}
Now add extension
private let arrayParametersKey = "arrayParametersKey"
/// Extenstion that allows an array be sent as a request parameters
extension Array {
/// Convert the receiver array to a `Parameters` object.
func asParameters() -> Parameters {
return [arrayParametersKey: self]
}
}
/// Convert the parameters into a json array, and it is added as the request body.
/// The array must be sent as parameters using its `asParameters` method.
struct ArrayEncoding: ParameterEncoding {
/// The options for writing the parameters as JSON data.
public let options: JSONSerialization.WritingOptions
/// Creates a new instance of the encoding using the given options
///
/// - parameter options: The options used to encode the json. Default is `[]`
///
/// - returns: The new instance
public init(options: JSONSerialization.WritingOptions = []) {
self.options = options
}
public func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
var urlRequest = try urlRequest.asURLRequest()
guard let parameters = parameters,
let array = parameters[arrayParametersKey] else {
return urlRequest
}
do {
let data = try JSONSerialization.data(withJSONObject: array, options: options)
if urlRequest.value(forHTTPHeaderField: "Content-Type") == nil {
urlRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")
}
urlRequest.httpBody = data
} catch {
throw AFError.parameterEncodingFailed(reason: .jsonEncodingFailed(error: error))
}
return urlRequest
}
}