Swift - encode URL

Question

If I encode a string like this:

var escapedString = originalString.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)

it does

Answer 1

None of these answers worked for me. Our app was crashing when a url contained non-English characters.

 let unreserved = "-._~/?%$!:"
 let allowed = NSMutableCharacterSet.alphanumeric()
     allowed.addCharacters(in: unreserved)

 let escapedString = urlString.addingPercentEncoding(withAllowedCharacters: allowed as CharacterSet)

Depending on the parameters of what you are trying to do, you may want to just create your own character set. The above allows for english characters, and -._~/?%$!:

Answer 2

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)\'")
}

Answer 3

Swift 4:

It depends by the encoding rules followed by your server.

Apple offer this class method, but it don't report wich kind of RCF protocol it follows.

var escapedString = originalString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)!

Following this useful tool you should guarantee the encoding of these chars for your parameters:

• $ (Dollar Sign) becomes %24
• & (Ampersand) becomes %26
• + (Plus) becomes %2B
• , (Comma) becomes %2C
• : (Colon) becomes %3A
• ; (Semi-Colon) becomes %3B
• = (Equals) becomes %3D
• ? (Question Mark) becomes %3F
• @ (Commercial A / At) becomes %40

In other words, speaking about URL encoding, you should following the RFC 1738 protocol.

And Swift don't cover the encoding of the + char for example, but it works well with these three @ : ? chars.

So, to correctly encoding each your parameter , the .urlHostAllowed option is not enough, you should add also the special chars as for example:

encodedParameter = parameter.replacingOccurrences(of: "+", with: "%2B")

Hope this helps someone who become crazy to search these informations.

Answer 4

Everything is same

var str = CFURLCreateStringByAddingPercentEscapes(
    nil,
    "test/test",
    nil,
    "!*'();:@&=+$,/?%#[]",
    CFStringBuiltInEncodings.UTF8.rawValue
)

// test%2Ftest

Answer 5

let Url = URL(string: urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? "")

Answer 6

Swift 3:

let originalString = "http://www.ihtc.cc?name=htc&title=iOS开发工程师"

1. encodingQuery:

let escapedString = originalString.addingPercentEncoding(withAllowedCharacters:NSCharacterSet.urlQueryAllowed)

result:

"http://www.ihtc.cc?name=htc&title=iOS%E5%BC%80%E5%8F%91%E5%B7%A5%E7%A8%8B%E5%B8%88" 

---

2. encodingURL:

let escapedString = originalString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)

result:

"http:%2F%2Fwww.ihtc.cc%3Fname=htc&title=iOS%E5%BC%80%E5%8F%91%E5%B7%A5%E7%A8%8B%E5%B8%88"