How do I URL encode a string

Question

I have a URL string (NSString) with spaces and & characters. How do I url encode the entire string (including the & ampersand character and spaces)?

Answer 1

In my case where the last component was Arabic letters I did the following in Swift 2.2:

extension String {

 func encodeUTF8() -> String? {

    //If I can create an NSURL out of the string nothing is wrong with it
    if let _ = NSURL(string: self) {

        return self
    }

    //Get the last component from the string this will return subSequence
    let optionalLastComponent = self.characters.split { $0 == "/" }.last


    if let lastComponent = optionalLastComponent {

        //Get the string from the sub sequence by mapping the characters to [String] then reduce the array to String
        let lastComponentAsString = lastComponent.map { String($0) }.reduce("", combine: +)


        //Get the range of the last component
        if let rangeOfLastComponent = self.rangeOfString(lastComponentAsString) {
            //Get the string without its last component
            let stringWithoutLastComponent = self.substringToIndex(rangeOfLastComponent.startIndex)


            //Encode the last component
            if let lastComponentEncoded = lastComponentAsString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.alphanumericCharacterSet()) {


            //Finally append the original string (without its last component) to the encoded part (encoded last component)
            let encodedString = stringWithoutLastComponent + lastComponentEncoded

                //Return the string (original string/encoded string)
                return encodedString
            }
        }
    }

    return nil;
}
}

usage:

let stringURL = "http://xxx.dev.com/endpoint/nonLatinCharacters"

if let encodedStringURL = stringURL.encodeUTF8() {

    if let url = NSURL(string: encodedStringURL) {

      ...
    }

} 

Answer 2

Use NSURLComponents to encode HTTP GET parameters:

    var urlComponents = NSURLComponents(string: "https://www.google.de/maps/")!
    urlComponents.queryItems = [
        NSURLQueryItem(name: "q", value: String(51.500833)+","+String(-0.141944)),
        NSURLQueryItem(name: "z", value: String(6))
    ]
    urlComponents.URL     // returns https://www.google.de/maps/?q=51.500833,-0.141944&z=6

http://www.ralfebert.de/snippets/ios/encoding-nsurl-get-parameters/

Answer 3

Here's a production-ready flexible approach in Swift 4:

public extension CharacterSet {

    public static let urlQueryParameterAllowed = CharacterSet.urlQueryAllowed.subtracting(CharacterSet(charactersIn: "&?"))

    public static let urlQueryDenied           = CharacterSet.urlQueryAllowed.inverted()
    public static let urlQueryKeyValueDenied   = CharacterSet.urlQueryParameterAllowed.inverted()
    public static let urlPathDenied            = CharacterSet.urlPathAllowed.inverted()
    public static let urlFragmentDenied        = CharacterSet.urlFragmentAllowed.inverted()
    public static let urlHostDenied            = CharacterSet.urlHostAllowed.inverted()

    public static let urlDenied                = CharacterSet.urlQueryDenied
        .union(.urlQueryKeyValueDenied)
        .union(.urlPathDenied)
        .union(.urlFragmentDenied)
        .union(.urlHostDenied)


    public func inverted() -> CharacterSet {
        var copy = self
        copy.invert()
        return copy
    }
}



public extension String {
    func urlEncoded(denying deniedCharacters: CharacterSet = .urlDenied) -> String? {
        return addingPercentEncoding(withAllowedCharacters: deniedCharacters.inverted())
    }
}

Example usage:

print("Hello, World!".urlEncoded()!)
print("You&Me?".urlEncoded()!)
print("#Blessed 100%".urlEncoded()!)
print("Pride and Prejudice".urlEncoded(denying: .uppercaseLetters)!)

Output:

Hello,%20World!
You%26Me%3F
%23Blessed%20100%25
%50ride and %50rejudice

Answer 4

//This is without test

NSMutableCharacterSet* set = [[NSCharacterSet alphanumericCharacterSet] mutableCopy];
[set addCharactersInString:@"-_.~"];
NSString *encode = [test stringByAddingPercentEncodingWithAllowedCharacters:set];

Answer 5

This code helped me for encoding special characters

NSString* encPassword = [password stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet alphanumericCharacterSet]];

Answer 6

Apple's advice, in the 10.11 release notes, is:

If you need to percent-encode an entire URL string, you can use this code to encode a NSString intended to be a URL (in urlStringToEncode):

NSString *percentEncodedURLString =
  [[NSURL URLWithDataRepresentation:[urlStringToEncode dataUsingEncoding:NSUTF8StringEncoding] relativeToURL:nil] relativeString];