Encode '+' using URLComponents in Swift

Question

This is how I add query params to a base URL:

let baseURL: URL = ...
let queryParams: [AnyHashable: Any] = ...
var components = URLComponents(url: baseURL, r         


        

Answer 1

URLComponents is behaving correctly: the + is not being percent-encoded because it is legal as it stands. You can force the + to be percent-encoded by using .alphanumerics, as explained already by Forest Kunecke (I got the same result independently but he was well ahead of me in submitting his answer!).

Just a couple of refinements. The OP's value: "\($1)" is unnecessary if this is a string; you can just say value:$1. And, it would be better to form the URL from all its components.

This, therefore, is essentially the same solution as Forest Kunecke, but I think it is more canonical and it is certainly more compact ultimately:

let queryParams = ["hey":"ho+ha"]
var components = URLComponents()
components.scheme = "http"
components.host = "www.example.com"
components.path = "/somepath"
components.queryItems = queryParams.map { 
  URLQueryItem(name: $0, 
    value: $1.addingPercentEncoding(withAllowedCharacters: .alphanumerics)!) 
}
let finalURL = components.url

---

EDIT Rather better, perhaps, after suggested correction from Martin R: we form the entire query and percent-encode the pieces ourselves, and tell the URLComponents that we have done so:

let queryParams = ["hey":"ho+ha", "yo":"de,ho"]
var components = URLComponents()
components.scheme = "http"
components.host = "www.example.com"
components.path = "/somepath"
var cs = CharacterSet.urlQueryAllowed
cs.remove("+")
components.percentEncodedQuery = queryParams.map {
    $0.addingPercentEncoding(withAllowedCharacters: cs)! + 
    "=" + 
    $1.addingPercentEncoding(withAllowedCharacters: cs)!
}.joined(separator:"&")

// ---- Okay, let's see what we've got ----
components.queryItems
// [{name "hey", {some "ho+ha"}}, {name "yo", {some "de,ho"}}]
components.url
// http://www.example.com/somepath?hey=ho%2Bha&yo=de,ho