How to add Alamofire URL parameters - swift

Question

I have a working scenario using Postman passing in URL parameters. Now when I try to do it via Alamofire in Swift, it does not work.
How would you create this url in Alamofire?
http://localhost:8080/?test=123
_url = "http://localhost:8080/"
let parameters: Parameters = [
"test": "123"
]
Alamofire.request(_url,
method: .post,
parameters: parameters,
encoding: URLEncoding.default,
headers: headers

Answer 1

The problem is that you're using URLEncoding.default. Alamofire interprets URLEncoding.default differently depending on the HTTP method you're using.
For GET, HEAD, and DELETE requests, URLEncoding.default encodes the parameters as a query string and adds it to the URL, but for any other method (such as POST) the parameters get encoded as a query string and sent as the body of the HTTP request.
In order to use a query string in a POST request, you need to change your encoding argument to URLEncoding(destination: .queryString).
You can see more details about how Alamofire handles request parameters here.
Your code should look like:
_url = "http://localhost:8080/"
let parameters: Parameters = [
"test": "123"
]
Alamofire.request(_url,
method: .post,
parameters: parameters,
encoding: URLEncoding(destination: .queryString),
headers: headers)

Answer 2

If you want your parameters to be used in querystring, use .queryString as URLEncoding, as in:
(I assume you have headers somewhere)
let _url = "http://localhost:8080/"
let parameters: Parameters = [
"test": "123"
]
Alamofire.request(_url,
method: .post,
parameters: parameters,
encoding: URLEncoding.queryString,
headers: headers)
This form is suggested by Alamofire author because it's more coincise to the other, see screenshot:
See original here