Comments on: iPhone tip #1 – URL encoding in Objective-C

By: me

me — Wed, 16 Jun 2010 07:38:57 +0000

be sure to replace the ” with regular quotes when copy & paste this function … otherwise the compiler will get an error …

By: sugiarto

sugiarto — Mon, 23 Nov 2009 21:56:24 +0000

Thanks,
very help me..

By: Dan J

Dan J — Wed, 26 Aug 2009 17:02:05 +0000

I think you need to include ” in the list of escaped characters. Don’t forget to escape it in code, e.g.

CFSTR(”:/?#[]@!$&’()*+,;=\””)

http://en.wikipedia.org/wiki/Percent-encoding

This was very useful – thanks!

By: Samuel

Samuel — Mon, 27 Apr 2009 19:09:54 +0000

Thanks, that’s correct! I have edited the post!

+ (NSString *)urlEncodeValue:(NSString *)str
{
NSString *result = (NSString *) CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)str, NULL, CFSTR(“:/?#[]@!$&’()*+,;=”), kCFStringEncodingUTF8);
return [result autorelease];
}

By: onitake

onitake — Mon, 27 Apr 2009 15:55:45 +0000

unfortunately, this will not correctly escape characters reserved as uri part delimiters or sub-part delimiters.
if you want to do that roll your own converter or use CFURLCreateStringByAddingPercentEscapes instead. as you might already know, corefoundation is toll-free bridged to foundation, so you can just cast between cfstring and nsstring. but don’t forget to release/autorelease.

example:
NSString *encodedString = (NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef) unencodedString, NULL, NULL, kCFStringEncodingUTF8);

if you want to make it rfc 3986-safe, use the following code:
CFStringRef escapeChars = (CFStringRef) @”:/?#[]@!$&’()*+,;=”;NSString *encodedString = (NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef) unencodedString, NULL, escapeChars, kCFStringEncodingUTF8);

By: Peter Strömberg

Peter Strömberg — Wed, 08 Apr 2009 21:06:08 +0000

Ah, an iPhone category. Nice! Could someone explain to me why encoding is such a tricky subject? =)