Convert NSString to a form passable in a HTTP POST request

Question

Is there a simple way to escape a NSString so I can use it in a HTTP POST request?

I've tried stringByAddingPercentEscapesUsingEncoding, but the following:

[@"~!@#$%^&*()-+\"'" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]

gives me:

~!@%23$%25%5E&*()-+%22'

which is not usable in a HTTP POST query because the & is left unescaped; therefore the other end interprets whatever follows it as another argument.

Look up the URLEncoding category for NSString. It looks like it is under MIT License and you can find it by searching "NSString+URLEncoding.m" — Jesse Black, Jan 21 '12 at 03:18
@Maudicus: thanks, that worked, I'm posting it as an answer for Googlers. — houbysoft, Jan 21 '12 at 05:27
See also http://stackoverflow.com/questions/718429/creating-url-query-parameters-from-nsdictionary-objects-in-objectivec, http://stackoverflow.com/questions/1748981/nsurl-encoding-in-objc, http://stackoverflow.com/questions/2159341/nsstring-method-to-percent-escape-for-url — Isaac, Jan 21 '12 at 05:32

score 1 · Accepted Answer · answered Jan 21 '12 at 05:27

The following function, part of NSString+URLEncoding.m, does exactly what I need:

- (NSString *)encodedURLParameterString {
NSString *result = (NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                                       (CFStringRef)self,
                                                                       NULL,
                                                                       CFSTR(":/=,!$&'()*+;[]@#?"),
                                                                       kCFStringEncodingUTF8);
    return [result autorelease];
}

Convert NSString to a form passable in a HTTP POST request

1 Answers1