Alamofire URLRequestConvertible global headers - swift

Question

Recently, I replace my old Alamofire requests with URLRequestConvertible protocol, for example, the country route is something like this:
enum CountryRoute: URLRequestConvertible {
case countries
var path: String {
switch self {
case .countries : return Path.Common.countries.rawValue
}
}
var method: HTTPMethod {
return .get
}
public var headers: HTTPHeaders {
return ["X-Mode" : "Light"]
}
func asURLRequest() throws -> URLRequest {
let url = try "example.com".asURL()
var request = URLRequest(url: url.appendingPathComponent(path))
request.httpMethod = method.rawValue
request.headers = headers
request.timeoutInterval = TimeInterval(10*1000)
return try URLEncoding.default.encode(request,with: nil)
}
}
and final the request is like this:
shared.session.request(convertible).validate().responseData { (response) in
// Do something
}
as I understand for each route we set headers, but what if we have global headers like "Content-Type" or "Accept-Language" or even Bearer Token?
Are there any ways to prevent add repetitious headers and add them globally? or we have to add these headers to each route?

Answer 1

Alamofire already generates some headers for the whole session when you using the default Session:
let session = Session.default
or the AF reference (which uses the default Session behind the scenes)
Those default headers include Accept-Encoding, Accept-Language and User-Agent. As for Content-Type header, URLEncoding or JSONEncoding are responsible for setting the correct values. (JSONParameterEncoder or URLEncodedFormParameterEncoder when you passing Encodable types as parameters)
However, you can override those headers by creating a new Session using your own URLSessionConfiguration:
let configuration = URLSessionConfiguration.af.default // Alamofire's default URLSessionConfiguration
configuration.headers["Content-Type"] = "application/json"
let session = Session(configuration: configuration)
Note: For Bearer token, there is a mechanism which requires the implementation of RequestInterceptor protocol in order to intercept every request and append the correct header. Using the same protocol you can also provide a refresh token functionality.