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

Answer 1

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 2

-(NSString *)encodeUrlString:(NSString *)string {
  return CFBridgingRelease(
                    CFURLCreateStringByAddingPercentEscapes(
                        kCFAllocatorDefault,
                        (__bridge CFStringRef)string,
                        NULL,
                        CFSTR("!*'();:@&=+$,/?%#[]"),
                        kCFStringEncodingUTF8)
                    );
}

according to the following blog

Answer 3

swift code based on chown's objc answer in this thread.

extension String {
    func urlEncode() -> String {
        return CFURLCreateStringByAddingPercentEscapes(
            nil,
            self,
            nil,
            "!*'();:@&=+$,/?%#[]",
            CFStringBuiltInEncodings.UTF8.rawValue
        )
    }
}

Answer 4

//This is without test

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

Answer 5

I faced a similar problem passing complex strings as a POST parameter. My strings can contain Asian characters, spaces, quotes and all sorts of special characters. The solution I eventually found was to convert my string into the matching series of unicodes, e.g. "Hu0040Hu0020Hu03f5...." using [NSString stringWithFormat:@"Hu%04x",[string characterAtIndex:i]] to get the Unicode from each character in the original string. The same can be done in Java.

This string can be safely passed as a POST parameter.

On the server side (PHP), I change all the "H" to "\" and I pass the resulting string to json_decode. Final step is to escape single quotes before storing the string into MySQL.

This way I can store any UTF8 string on my server.

Answer 6

In Swift 3, please try out below:

let stringURL = "YOUR URL TO BE ENCODE";
let encodedURLString = stringURL.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)
print(encodedURLString)

Since, stringByAddingPercentEscapesUsingEncoding encodes non URL characters but leaves the reserved characters (like !*'();:@&=+$,/?%#[]), You can encode the url like the following code:

let stringURL = "YOUR URL TO BE ENCODE";
let characterSetTobeAllowed = (CharacterSet(charactersIn: "!*'();:@&=+$,/?%#[] ").inverted)
if let encodedURLString = stringURL.addingPercentEncoding(withAllowedCharacters: characterSetTobeAllowed) {
    print(encodedURLString)
}