POST from iPhone to PhP not working

Question

First time using POST

POST information is not getting from the iPhone to the PhP script. I get no errors anywhere. var_dump($_POST) shows empty. failed login returned. Any ideas where to look next or do I have a visible problem here:

     NSURL *url = [NSURL URLWithString:link];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

NSString *requestBodyString = [NSString stringWithFormat:@"txtuid=%@&txtpwd=%@", userName , password];
NSData *requestBody = [NSData dataWithBytes:[requestBodyString UTF8String]length:[requestBodyString length]];

[request setHTTPMethod:@"POST"];
[request setHTTPBody:requestBody];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"]; // added from first suggestion

connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];

After trying it six different ways, I took a modified version from a previous post.

And yet another attempt with the same results.

NSData *data = [[NSString stringWithFormat: @"txtuid=%@&txtpwd=%@", userName , password] dataUsingEncoding:NSUTF8StringEncoding];

// set up request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:link]];
[request setHTTPMethod:@"POST"];
NSString *boundary = [NSString stringWithString:@"--------------------------------------------------"];
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
[request addValue:contentType forHTTPHeaderField:@"Content-Type"];

// body
NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Type: text/plain\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];  
[body appendData:[NSData dataWithData:data]];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];  

[request setHTTPBody:body];
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];

Answer 1

Use following code. make sure that post string's receipt is a key and will be used in server. client side code

 NSString *receipt1 = @"username";

    NSString *post =[NSString stringWithFormat:@"receipt=%@",receipt1];
   NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
    [request setURL:[NSURL URLWithString:@"http://localhost:8888/validateaction.php"]];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];

    NSHTTPURLResponse* urlResponse = nil;
    NSError *error = [[NSError alloc] init];
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];
    NSString *result = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
    NSLog(@"Response Code: %d", [urlResponse statusCode]);

    if ([urlResponse statusCode] >= 200 && [urlResponse statusCode] < 300)
    {
        NSLog(@"Response: %@", result);
    }

}

server side php script.

validation.php

<?php
 if(_POST)
    {
        if($_POST['receipt'] == 'username')
        {
            echo "post successfull";
         $receipt   = $_POST['key1'];
         echo $receipt;
        }
        else
    {
        echo "not post";
    }
?>

Answer 2

See my answer here about how to use POST to upload an image. It posts to forms in a PHP file. Same concept for posting data and not uploading images, but this is a working example of how to post to a PHP script using Objective-C.

Answer 3

Try not setting the content-type explicitly. Avoid the following line:

[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"];

If you are using the iPhone simulator, I would strongly recommend you using a PROXY for HTTP debugging purposes. mitmproxy is awesome. And very easy to setup on Mac OS X.