iOS: URL Encode A String

ios_url_encode_string.m

This is useful so that before you process any URL request from a URL String, this URL String becomeURL encoded and gets replaced to percent escapes.

iOS 5: iOS 5 requires A Toll-Free Bridging

- (NSString *)escape:(NSString *)text
{
    return CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(                                                                     NULL, (__bridge CFStringRef)text, NULL, CFSTR("!*'();:@&=+$,/?%#[]"), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding)));
}

Previous iOS:

- (NSString *)escape:(NSString *)text
{
    return (NSString *)CFURLCreateStringByAddingPercentEscapes(
        NULL,
        (CFStringRef)text,
        NULL,
        (CFStringRef)@"!*'();:@&=+$,/?%#[]",
        CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));