Replacement for stringByAddingPercentEscapesUsingE

Question

In iOS8 and prior I can use:

NSString *str = ...; // some URL
NSString *result = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

in iOS9 stringByAddingPercentEscapesUsingEncoding has been replaced with stringByAddingPercentEncodingWithAllowedCharacters:

NSString *str = ...; // some URL
NSCharacterSet *set = ???; // where to find set for NSUTF8StringEncoding?
NSString *result = [str stringByAddingPercentEncodingWithAllowedCharacters:set];

and my question is: where to find needed NSCharacterSet (NSUTF8StringEncoding) for proper replacement of stringByAddingPercentEscapesUsingEncoding?

Answer 1

Objective-C

this code work for me :

urlString = [urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLFragmentAllowedCharacterSet]];

Answer 2

The deprecation message says (emphasis mine):

Use stringByAddingPercentEncodingWithAllowedCharacters(_:) instead, which always uses the recommended UTF-8 encoding, and which encodes for a specific URL component or subcomponent since each URL component or subcomponent has different rules for what characters are valid.

So you only need to supply an adequate NSCharacterSet as argument. Luckily, for URLs there's a very handy class method called URLHostAllowedCharacterSet that you can use like this:

let encodedHost = unencodedHost.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())

Update for Swift 3 -- the method becomes the static property urlHostAllowed:

let encodedHost = unencodedHost.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)

Be aware, though, that:

This method is intended to percent-encode an URL component or subcomponent string, NOT an entire URL string.

Answer 3

URLHostAllowedCharacterSet is NOT WORKING FOR ME. I use URLFragmentAllowedCharacterSet instead.

OBJECTIVE -C

NSCharacterSet *set = [NSCharacterSet URLFragmentAllowedCharacterSet];
NSString * encodedString = [@"url string" stringByAddingPercentEncodingWithAllowedCharacters:set];

SWIFT - 4

"url string".addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)

The following are useful (inverted) character sets:

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

Answer 4

For Objective-C：

NSString *str = ...; // some URL
NSCharacterSet *set = [NSCharacterSet URLHostAllowedCharacterSet]; 
NSString *result = [str stringByAddingPercentEncodingWithAllowedCharacters:set];

where to find set for NSUTF8StringEncoding?

There are predefined character sets for the six URL components and subcomponents which allow percent encoding. These character sets are passed to -stringByAddingPercentEncodingWithAllowedCharacters: .

 // Predefined character sets for the six URL components and subcomponents which allow percent encoding. These character sets are passed to -stringByAddingPercentEncodingWithAllowedCharacters:.
@interface NSCharacterSet (NSURLUtilities)
+ (NSCharacterSet *)URLUserAllowedCharacterSet;
+ (NSCharacterSet *)URLPasswordAllowedCharacterSet;
+ (NSCharacterSet *)URLHostAllowedCharacterSet;
+ (NSCharacterSet *)URLPathAllowedCharacterSet;
+ (NSCharacterSet *)URLQueryAllowedCharacterSet;
+ (NSCharacterSet *)URLFragmentAllowedCharacterSet;
@end

The deprecation message says (emphasis mine):

Use stringByAddingPercentEncodingWithAllowedCharacters(_:) instead, which always uses the recommended UTF-8 encoding, and which encodes for a specific URL component or subcomponent since each URL component or subcomponent has different rules for what characters are valid.

So you only need to supply an adequate NSCharacterSet as argument. Luckily, for URLs there's a very handy class method called URLHostAllowedCharacterSet that you can use like this:

NSCharacterSet *set = [NSCharacterSet URLHostAllowedCharacterSet]; 

Be aware, though, that:

This method is intended to percent-encode an URL component or subcomponent string, NOT an entire URL string.

Answer 5

What is the meaning of "This method is intended to percent-encode an URL component or subcomponent string, NOT an entire URL string." ? – GeneCode Sep 1 '16 at 8:30

It means that you are not supposed to encode the https://xpto.example.com/path/subpath of the url, but only what goes after the ?.

Supposed, because there are use-cases for doing it in cases like:

https://example.com?redirectme=xxxxx

Where xxxxx is a fully encoded URL.

Answer 6

For Swift 3.0

You can use urlHostAllowed characterSet.

/// Returns the character set for characters allowed in a host URL subcomponent.

public static var urlHostAllowed: CharacterSet { get }

WebserviceCalls.getParamValueStringForURLFromDictionary(settingsDict as! Dictionary<String, AnyObject>).addingPercentEncoding(withAllowedCharacters: CharacterSet.urlHostAllowed)