Swift - encode URL

ios, swift, urlencode

Solution

Swift 3

In Swift 3 there is `addingPercentEncoding`

let originalString = "test/test"
let escapedString = originalString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)
print(escapedString!)

Output:

test%2Ftest

Swift 1

In iOS 7 and above there is `stringByAddingPercentEncodingWithAllowedCharacters`

var originalString = "test/test"
var escapedString = originalString.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())
println("escapedString: \(escapedString)")

Output:

test%2Ftest

The following are useful (inverted) character sets:

URLFragmentAllowedCharacterSet  "#%<>[\]^`{|}
URLHostAllowedCharacterSet      "#%/<>?@\^`{|}
URLPasswordAllowedCharacterSet  "#%/:<>?@[\]^`{|}
URLPathAllowedCharacterSet      "#%;<>?[\]^`{|}
URLQueryAllowedCharacterSet     "#%<>[\]^`{|}
URLUserAllowedCharacterSet      "#%/:<>?@[\]^`

If you want a different set of characters to be escaped create a set: Example with added "=" character:

var originalString = "test/test=42"
var customAllowedSet =  NSCharacterSet(charactersInString:"=\"#%/<>?@\\^`{|}").invertedSet
var escapedString = originalString.stringByAddingPercentEncodingWithAllowedCharacters(customAllowedSet)
println("escapedString: \(escapedString)")

Output:

test%2Ftest%3D42

Example to verify ascii characters not in the set:

func printCharactersInSet(set: NSCharacterSet) {
    var characters = ""
    let iSet = set.invertedSet
    for i: UInt32 in 32..<127 {
        let c = Character(UnicodeScalar(i))
        if iSet.longCharacterIsMember(i) {
            characters = characters + String(c)
        }
    }
    print("characters not in set: \'\(characters)\'")
}

Problem

If I encode a string like this: ``` var escapedString = originalString.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding) ``` it doesn't escape the slashes `/`. I've searched and found this Objective C code: ``` NSString *encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes( NULL, (CFStringRef)unencodedString, NULL, (CFStringRef)@"!*'();:@&=+$,/?%#[]", kCFStringEncodingUTF8 ); ``` Is there an easier way to encode an URL and if not, how do I write this in Swift?

Original source

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