Iphone sdk, How to post data to web server? anybody has example ?

Question

Hi, guys, I want to post data to web server, like username and password, on the web server, I used PHP to echo yes or no, I attached all the code. Can anybody help me out, what is wrong with the code. Since it always says incorrect password or username. I tried to test the php code with username and password inside, it is working. So please help me. Thank you.

Header file

@interface kiksyloginViewController : UIViewController {
    IBOutlet UITextField *usernameField;
    IBOutlet UITextField *passwordField;
    IBOutlet UIButton *loginButton;
}

@property (nonatomic, retain) UITextField *usernameField;
@property (nonatomic, retain) UITextField *passwordField;
@property (nonatomic, retain) UIButton *loginButton;

- (IBAction) login: (id) sender;

@end

Implementation file

#import "kiksyloginViewController.h"

@implementation kiksyloginViewController

@synthesize usernameField;
@synthesize passwordField;
@synthesize loginButton;

- (IBAction) login: (id) sender
{

    NSString *post =[NSString stringWithFormat:@"username=%@&password=%@",usernameField.text, passwordField.text];

    NSString *hostStr = @"http://localhost/userlogin.php";
    hostStr = [hostStr stringByAppendingString:post];
    NSData *dataURL =  [NSData dataWithContentsOfURL: [ NSURL URLWithString: hostStr ]];    
    NSString *serverOutput = [[NSString alloc] initWithData:dataURL encoding: NSASCIIStringEncoding];


    if([serverOutput isEqualToString:@"Yes"]){

        UIAlertView *alertsuccess = [[UIAlertView alloc] initWithTitle:@"Congrats" message:@"You are authorized "
                                                              delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

        [alertsuccess show];
        [alertsuccess release];

    } else {
        UIAlertView *alertsuccess = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Username or Password Incorrect"
                                                              delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alertsuccess show];
        [alertsuccess release];

    }
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn’t have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren’t in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [super dealloc];
}

@end

PHP file

<?php 
//$Container = new Container; 

$u = $_GET['username']; 
$pw =$_GET['password']; 
$check = "select username, password from user where username='$u' and password='$pw'"; 
function myDbconn() 

{ 
    mysql_connect("localhost", "root","") or die(); 
    mysql_select_db("test") or die (mysql_error()); 
} 

myDbconn(); 


$login = mysql_query($check) or die (mysql_error()); 
//$run = DB()->select($check); 



if (mysql_num_rows($login)==1){ 
    //$row = DB()->fetch($run); 
    //$row = DB()->fetch($login); 
    $row = mysql_fetch_assoc($login); 
    echo 'yes'; 
    exit;         
} 
else { 
    echo 'No'; 
    exit; 
} 

?>

Answer 1

The first issue I see that's probably the biggest is that there's no "?" anywhere. Specifically, this:

@"username=%@&password=%@"

should look more like this:

@"?username=%@&password=%@"

Because you're not actually posting to the server, you're just using a GET request and URL parameters.

I don't know if you plan on getting a web server and PHP running on your device in the background, but at some point I assume you will change http://localhost to something else, and hopefully you will sanitize your SQL query before you let people navigate to your webpage and type in anything they want in the URL query.