Question

I have a simple POST coming from my iphone app. Its working fine, except passing an ampersand causes the backend to break – it’s almost like its treating it like a GET request (ampersands seperate the variable names). Do I need to do some kind of encoding first? Here is the code:

NSString *content = [[NSString alloc] initWithFormat:@"data=%@&email=%@", str, emailAddress.text];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://www.myurl.com/myscript.php"]];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:[content dataUsingEncoding:NSISOLatin1StringEncoding]];

// generates an autoreleased NSURLConnection
[NSURLConnection connectionWithRequest:request delegate:self];

Answer 1

Edit: As stringByAddingPercentEscapesUsingEncoding: should be used to encode parts of the query, not the whole one, you should be using another method instead.

Unfortunately, Foundation doesn’t provide such a method, so you need to reach to CoreFoundation:

- (NSString *)stringByURLEncodingString:(NSString *)string {
    return (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(
        kCFAllocatorDefault,
        (__bridge CFStringRef)string,
        NULL, // or (__bridge CFStringRef)(@"[].")
        (__bridge CFStringRef)(@":/?&=;+!@#$()',*"),
        kCFStringEncodingUTF8
    );
}

---

You can use

- stringByAddingPercentEscapesUsingEncoding:

In your case it will look like this:

NSString * content = [[NSString alloc] initWithFormat:@"data=%@&email=%@", [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding], [emailAddress.text  stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

You can do this in this way, too:

NSString *dataStr = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *emailStr = [emailAddress.text  stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSString *content = [[NSString alloc] initWithFormat:@"data=%@&email=%@", dataStr, emailStr];