Swift encode & in the GET parameter - ios

Question

I have a simple GET request for login. Username is Silver and password is MOto&#10
I am using SwiftHttp framework for handling requests. On hitting login request, I always get response as false.
However on hitting the login request url on browser (replaced actual domain with server) I get true :
https://server/api/check-access/by-login-pass?_key=wlyOF7TM8Y3tn19KUdlq&login=silver&pass=MOto%26#10
There is something wrong with encoding & in the password. Though I have replaced it with percent encoding. Here is my code :
do {
let passwordString = self.convertSpecialCharacters(string: password.text!)
print("%#", passwordString)
let opt = try HTTP.GET(Constants.kLoginUrl, parameters: ["login": username.text!, "pass": passwordString])
opt.start { response in
if let err = response.error {
print("error: \(err.localizedDescription)")
return
}
print("opt finished: \(response.description)")
self.parseLoginResponse(response.data)
}
} catch _ as NSError {
}
And this is convertSpecialCharacters :
func convertSpecialCharacters(string: String) -> String {
var newString = string
let arrayEncode = ["&", "<", ">", "\"", "'", "-", "..."]
for (escaped_char) in arrayEncode {
newString = newString.encode(escaped_char)
}
return newString
}
Extension for encoding :
extension String {
func encode(_ chars: String) -> String
{
let forbidden = CharacterSet(charactersIn: chars)
return self.addingPercentEncoding(withAllowedCharacters: forbidden.inverted) ?? self
}
}

Answer 1

A suitable way is to use URLComponents which handles all percent encoding:
var urlComponents = URLComponents(string: "https://server/api/check-access/by-login-pass")!
let queryItems = [URLQueryItem(name:"_key", value:"wlyOF7TM8Y3tn19KUdlq"),
URLQueryItem(name:"login", value:"silver"),
URLQueryItem(name:"pass", value:"MOto&#10")]
urlComponents.queryItems = queryItems
let url = urlComponents.url
print(url) // "https://server/api/check-access/by-login-pass?_key=wlyOF7TM8Y3tn19KUdlq&login=silver&pass=MOto%26#10"
PS: I totally agree with luk2302's comment.

Answer 2

I've decided to go full custom for my GET-request, since everything else didn't want to work and got me angry. I used the request for something different though, like getting a list from our server. The login is done via POST requests which was easier.
However, to stick with GET-requests:
I needed characters like "+" and "/" encoded...
First I couldn't get the "+" encoded with the "stringByAddingPercentEncodingWithAllowedCharacters" method.
So I have built my own extension for String:
extension String
{
return CFURLCreateStringByAddingPercentEscapes(
nil,
self as CFString,
nil,
"!*'();:#&=+$,/?%#[]" as CFString,
CFStringBuiltInEncodings.UTF8.rawValue
) as String
}
2nd step was to add this to my url for the final request. I wanted to use URLQueryItems and add them to the url by using url.query or url.queryItems. Bad surprise: My already correctly encoded string got encoded again and every "%" inside of it became "%25" making it invalid. -.-
So now I have appended each encoded value to a string which will be added to the url. Doesn't feel very "swift" but ok..
let someUrl = "https://example.com/bla/bla.json"
var queryString = ""
var index = 0
// dicParam is of type [String: AnyObject] with all needed keys and values for the query
for (key, value) in dicParam
{
let encodedValue = (value as! String).encodeUrl()
if index != 0
{
queryString.append("&\(key)=\(encodedValue)")
}
else
{
queryString.append("?\(key)=\(encodedValue)")
}
index += 1
}
let url = URLComponents(string: someUrl + queryString)!
Hope this helps someone and saves a few hours :/