Reputation: 247

Undefined index error when posting from HTML form

I am using the following html form to get a login:

<!DOCTYPE html>   
<!-- This is a html file for logging in to the virtual adviser -->
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 
    <head>
        <meta charset="UTF-8">
        <title> Pet Tracker Login</title>
        <link rel="stylesheet" type="text/css" media='screen' href="css/login.screen.css">
    </head>
    <body>
        <!-- The div that displays the login form-->
        <div class="login">
            <h1><strong>Welcome to the Pet Tracker System</strong></h1>
            <form action="validateLogin.php" method="POST">
            <fieldset>
            <label for="user">Username</label>
            <p><input type="text" required id = "user" name = "Username" value=""></p>
            <label for="pass">Password</label>
            <p><input type="password" required id = "pass" name = "Password" value=""></p>
            <!-- <p><a href="#">Forgot Password?</a></p> -->
            <p><input type="submit" value="Login"></p>
            </fieldset>
            </form>
            <!-- include the  logo with green background -->
            <img src="images/threeDeePawPrint.png" alt="paw Logo" style="width:194px;height:97px" class = "center">
        </div>
    </body>
</html>

but apparently this is not posting because I get an undefined index error on the validateLogin.php page:

<?php 
// start the session for this page and create the array to hold error messages
session_start();
$errmsg_arr = array();
$errflag = false;

$username = 'root';
$password = '';
$url = 'localhost';
$database = 'pet_tracker';

/*  Note that above variables are using single quote for string. When they
    get replaced in the connection statement below, single quotes within
    single quotes will fail, therefore, the string argument in $conn= statement
    must be double quotes
*/

try
{
    $conn = new PDO("mysql:host=$url; dbname=$database",$username,$password);       //create PDO object (PHP Data Objects = PDO)
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);                 /*set the attribute that controls the error mode once the database
                                                                                    has been connected to, so that it throws exceptions (PDO switches to
                                                                                    "silent failure" mode after establishing a successful connection) */
    $conn->exec('SET NAMES "utf8"');                                                    /* PDO has a method exec that runs SQL scripts. Configure the character
                                                                                    encoding to UTF-8 for special characters like smart quotes */

}   
catch (PDOException $e)
{
    echo $e;
    $output = 'Unable to connect to the database server.'.                          //the '.' is the concatenation operator for a string
    $e->getMessage();                                                               //the '->' is the equivalent of the dot operator in Java
    include 'error.html.php';
    exit();
}

//get the username and password posted from the login page (index.php)
if(isset($_POST['user'])) echo 'index user has value'.$_POST['user'];
if(isset($_POST['pass'])) echo 'index user has value'.$_POST['pass'];

$user = $_POST['user'];
$pass = $_POST['pass'];


//query the database for the posted data from form
    $result = $conn->prepare("SELECT * FROM client WHERE username= :un AND password= :pw");
    $result->bindParam(':un', $user);
    $result->bindParam(':pw', $pass);
    $result->execute();
    $rows = $result->fetch(PDO::FETCH_NUM);
    if($rows > 0) 
    {
    $result = $conn->prepare("SELECT * FROM client WHERE username = :un");  //PDO can only handle a row of data at a time?? Cannot select first_name from students, etc.??
    $result->bindParam(':un',$user);
    $result->execute();
    $name = $result->fetchColumn(1);    
    $_SESSION['name'] = $name;
    $_SESSION['user'] = $user;          //the next page employee.php will need the username to get information from the database
    header("location: employee.php");
    }
else{
    $errmsg_arr[] = 'Username and Password are not found';
    $errflag = true;
    }

if($errflag) {
    $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
    session_write_close();
    header("location: index.php");
    exit();
}
?>

The errors I get are in the lines where I set the $user and $pass variables. The errors I get are:

Notice: Undefined index: user in C:\xampp\htdocs\PetTracker\validateLogin.php on line 41

Notice: Undefined index: pass in C:\xampp\htdocs\PetTracker\validateLogin.php on line 42

Upvotes: 0

Answers (3)

Zohaib Aslam

Reputation: 336

Index of $_POST variable should be exactly same as the name attribute of the HTML Input. Name of your input field is Username while you are trying to access it as $_POST['user'] which is entirely wrong. Either change the name to user or the $_POST index to Username

Also consider reviewing your code, there are bunch of other mistakes as well. Just for instance, you need to capitalize the first letter of location as Location in the header function. Also consider checking the post-back by writing the following condition on the first line of validateLogin.php page

if($_SERVER['REQUEST_METHOD']=='POST'&&isset($_POST['submit'])){
//Your code
}else{
//redirect to somewhere else...
}

Upvotes: 1

Ghulam Ali

Reputation: 1935

PHP Notice of Undefined Index means that the array Key does not find in the array. If you wish to view all the elements of array you can use print_r($_POST);

To fix your problem just change $_POST['user'] to $_POST['Username'] and $_POST['pass'] to $_POST['Password'];

Upvotes: 0

József Cserkó

Reputation: 299

Html create input keys from name attribute.

Solution 1: change HTML

<input type="text" required id="user" name="user" value="">

Or solution 2: change PHP

$user = $_POST['Username'];
$pass = $_POST['Password'];

Upvotes: 0

Undefined index error when posting from HTML form

Answers (3)

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