Question

Although there are many related questions, I don’t see one that addresses adding multiple key/value pairs to an NSURLRequest.

I want to add a simple username and password to a request. I’m unsure of how to add multiple pairs, and also of the encoding. I get a valid connection and response, but the response indicates it hasn’t been able to interpret the request properly.

Here’s what I’ve got. Thanks in advance.

NSURL *authenticateURL = [[NSURL alloc] initWithString:@"https://www.the website.com/authenticate"];
NSMutableURLRequest *authenticateRequest = [[NSMutableURLRequest alloc] initWithURL:authenticateURL];
[authenticateRequest setHTTPMethod:@"POST"];
NSString *myRequestString = @"username=";
[myRequestString stringByAppendingString:username];
[myRequestString stringByAppendingString:@"&"];
[myRequestString stringByAppendingString:@"password="];
[myRequestString stringByAppendingString:password];
NSData *requestData = [NSData dataWithBytes:[myRequestString UTF8String] length:[myRequestString length]];
[authenticateRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"];
[authenticateRequest setHTTPBody: requestData];
[authenticateRequest setTimeoutInterval:30.0];

connection = [[NSURLConnection alloc] initWithRequest:authenticateRequest delegate:self]; 

Answer 1

You’re not using NSString correctly (your myRequestString, in fact, will read “username=”). Instead, try this:

NSMutableString *myRequestString = [NSMutableString stringWithString:@"username="];
[myRequestString appendString:username];
[myRequestString appendString:@"&password="];
[myRequestString appendString:password];

---

Further to this great answer, just a typical example code:

-(NSString *)buildKeyValuePostString
    {
    NSString *username = @"[e-mail]";
    NSString *password = @"macintosh";

    NSMutableString *r = [NSMutableString stringWithString:@""];

    [r appendString:@"command=listFileNames"];
    [r appendString:@"&"];

    [r appendString:@"name=blah"];
    [r appendString:@"&"];

    [r appendString:@"user="];
    [r appendString: [username stringByUrlEncoding] ];
    [r appendString:@"&"];

    [r appendString:@"password="];
    [r appendString: [password stringByUrlEncoding] ];

    return r;
    }

and here’s the category to do the difficult/annoying job of url encoding

-(NSString *)stringByUrlEncoding
    {
    return (NSString *)CFBridgingRelease(
             CFURLCreateStringByAddingPercentEscapes(
                NULL,
                (CFStringRef)self,
                NULL,
                (CFStringRef)@"!*'();:@&=+$,/?%#[]",
                kCFStringEncodingUTF8)
                );

    // with thanks to http://www.cocoanetics.com/2009/08/url-encoding/
    // modified for ARC use 2014
    }

Hope it helps someone.