Sending data with POST, issue with character encoding

Question

I am having issues with my NSURLRequest and doing a POST whenever the string includes %, for example.

On my website, I can see that the encoding is ISO-8859-1,utf-8 for Accept-Charset but for some reason I cannot get the POST to work if it includes "%&$" etc. It seems like it won't encode it with UTF-8 encoding. Am I doing something wrong in the below code?

NSData *postData = [credentials dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO];
NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:@"http://www.website.com/login.php"]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];

Answer 1

You may want to hear "Content-Transfer-Encoding".

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: binary

or if you have problems specially with those chars

Content-Transfer-Encoding: base64

EDIT: The "application/x-www-form-urlencoded" makes the "%" signs happen.

Answer 2

I'm not sure the exact answer to your problem, but try ASIHTTPRequest, specifically the ASIFormDataRequest and see if you get the same sort of problem. It's a very good library and encapsulates a lot of the encoding issues you might otherwise have to deal with yourself.

Best regards,

Answer 3

I had the EXACT SAME ISSUE, and its the URL encoding that's the issue (for example / = %2F). I found this snippet that will properly encode your text, as Apple's stringByAddingPercentEscapes is a severely broken method, and you shouldn't use it. Use this code below.

NSString * encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)credentials, NULL, (CFStringRef)@"!*'();:@+$,/?%#[]", kCFStringEncodingUTF8 );

Put this before the dataUsingEncoding method, and replace the dataUsingEncoding method with:

NSData *postData = [encodedString dataUsingEncoding:NSUTF8StringEncoding];