What is the iOS proper URL encoding of "+" character?

Question

Is there seriously not a way natively to URL Encode the value of a query string parameter that has a "+" character in it?

e.g.

me+blah@domain.net

to

me%2Bblah%40@domain.net?

I tried solutions like posted in these other questions, but those do not properly encode that email.

Swift - encode URL

How do I URL encode a string

A swift solution would be preferred as that is what I am working in at the moment, but I am capable of translating Objective-C Code to swift code for the most part.

Specifically I am trying to x-www-form-urlencoded encode query string values in the body of POST request.

Specify how the string/URL currently *is* being encoded (including at what steps such is applied) as context is very important to when `+` should, shouldn't, and might be percent encoded. The "proper encoding" is defined by these rules, outside (and long before) iOS. — user2864740, Oct 01 '14 at 19:59
@user2864740 I'm not sure I understand, I gave an example of input, and desired output. Currently the "+" character does not get encoded with any of the solutions provided on the other stackoverflow questions. — thatidiotguy, Oct 01 '14 at 20:07

Aaron Brager · Accepted Answer · 2014-10-01T20:29:56.247

1

let email = "me+blah@domain.net"

let output = CFURLCreateStringByAddingPercentEscapes(nil, email as NSString, nil, ":/?@!$&'()*+,;=" as NSString, CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding))

// output = "me%2Bblah%40domain.net"

CFURLCreateStringByAddingPercentEscapes doesn't escape + or @ by default, but you can specify it (as I did along with other characters, in the ":/?@!$&'()*+,;=" string).

Edit: If you want output to be a Swift string:

let output = (CFURLCreateStringByAddingPercentEscapes(nil, email as NSString, nil, ":/?@!$&'()*+,;=" as NSString, CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding)) as NSString) as String

edited Oct 01 '14 at 20:29

answered Oct 01 '14 at 20:12

Aaron Brager

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(I'm assuming you meant `me%2Bblah%40domain.net` as your desired output, and not `me%2blah%40@domain.net` as you actually typed.) – Aaron Brager Oct 01 '14 at 20:13
You are correct, I had a typo, fixed now. I will try this out. – thatidiotguy Oct 01 '14 at 20:21
Hmm this returns a `CFString`, which apparently does not want to be coaxed into a Swift `String` since `CFString` is not a `NSString`. Any ideas? – thatidiotguy Oct 01 '14 at 20:22

score 0 · Answer 2 · answered Oct 01 '14 at 20:20

0

println(("me+blah@domain.net" as NSString)
    .stringByAddingPercentEncodingWithAllowedCharacters(
        NSCharacterSet.alphanumericCharacterSet()))

Output:

Optional("me%2Bblah%40domain%2Enet")

In Objective-C:

NSString *encodedString =
    ["me+blah@domain.net" stringByAddingPercentEncodingWithAllowedCharacters:
        [NSCharacterSet alphanumericCharacterSet]];

answered Oct 01 '14 at 20:20

rob mayoff

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But periods should not be encoded when the content type is `x-www-form-urlencoded` – thatidiotguy Oct 01 '14 at 20:21
You can add more characters to the character set, but is it really worth it? The periods will be decoded properly. You are **allowed** to encode more characters than you are **required** to encode. – rob mayoff Oct 01 '14 at 20:22

What is the iOS proper URL encoding of "+" character?

2 Answers2