how to set a default http header with alamofire - alamofire

Question

I want to set a header so that all requests include an authorized token header once the user logs in. I thought I could set the header in the shared alamofire manager by calling my setToken function but I don't think I'm doing it correctly. What's my mistake? Is there a better way of setting a default header for all alamofire requests?
class UserService : NSObject {
static let manager: Alamofire.Manager = Alamofire.Manager(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
class func setToken(token:String){
manager.session.configuration.HTTPAdditionalHeaders = [
"x-token": token
]
}
class func addFriend(user:LoggedUser, uname:String, callback:((success: Bool, errorMsg: String?)->Void)) {
let params:[String : AnyObject] = ["uname": uname]
let url = AppConfig.sharedInstance().baseURL() + "/user/\(user.userId!)/friends"
Alamofire.request(.POST, url , parameters:params, encoding:.JSON)
.responseJSON(options: .MutableContainers, completionHandler:{ (request, response, JSON, error) -> Void in
//token is not set in the request
}
}

Answer 1

Your code never make use of your custom manager, use following code:
class CustomManager: Manager {
static public let manager = CustomManager.generateManager()
class func generateManager()-> CustomManager {
var defaultHeaders = Alamofire.Manager.defaultHTTPHeaders ?? [:]
defaultHeaders["x-token""] = "token"
let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
configuration.HTTPAdditionalHeaders = defaultHeaders
let manager = CustomManager(configuration: configuration)
return manager
}
}
class UserService : NSObject {
class func addFriend(user:LoggedUser, uname:String, callback:((success: Bool, errorMsg: String?)->Void)) {
let params:[String : AnyObject] = ["uname": uname]
let url = AppConfig.sharedInstance().baseURL() + "/user/\(user.userId!)/friends"
CustomManager.manager(.POST, url , parameters:params, encoding:.JSON)
.responseJSON(options: .MutableContainers, completionHandler:{ (request, response, JSON, error) -> Void in
// ...
}
}

Answer 2

If you were using a custom SessionManager in Alamofire 4, now in Alamofire 5 it's called Session and you can create it this way:
let configuration = URLSessionConfiguration.default
var defaultHeaders = HTTPHeaders.default
defaultHeaders["X-API-Version"] = "1.0"
configuration.headers = defaultHeaders
let yourManager = Alamofire.Session(configuration: configuration)

Answer 3

So my mistake was using the class function rather than the shared instance when I made the request.
So it should be
Alamofire.Manager.sharedInstance.request(.POST, url , parameters:params, encoding:.JSON)
rather than
Alamofire.request(.POST, url , parameters:params, encoding:.JSON)

Answer 4

Create a class that conforms to protocol RequestAdapter. You will have to implement this function func adapt(_ urlRequest: URLRequest) throws -> URLRequest {. Inside it do:
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
var urlRequest = urlRequest
urlRequest.setValue("YourUserAgent", forHTTPHeaderField: "User-Agent")
return urlRequest
}
In this function you can add whatever headers you want.
And then do:
sessionManager.adapter = "Class that conforms to RequestAdapter", where sessionManager is your Alamofire SessionManager.