Question posted in
You can find the official documentation here.

AJAX POST (JQuery) to PHP is not working. How can I fix it? – Jquery ajax

I’m facing the POST issue for a while and I still can’t solve it. The AJAX doesn’t send data (i think) to my php file login.php in php folder. I’m still getting error, that index usernameData is undefined/does not exist.

Uncaught TypeError: Cannot use 'in' operator to search for '119' in <br />
<b>Notice</b>:  Undefined variable: mainusername in <b>/var/www/html/php/login.php</b> on line <b>17</b><br />
[]
    at s (jquery.min.js:2)
    at Function.each (jquery.min.js:2)
    at Object.success (login.js:131)
    at j (jquery.min.js:2)
    at Object.fireWith [as resolveWith] (jquery.min.js:2)
    at x (jquery.min.js:4)
    at XMLHttpRequest.<anonymous> (jquery.min.js:4)

sometimes it also returns nothing, just a blank console log.

Informations:

  • im using apache2, ubuntu 21.04, php7.4
  • php.ini file: post_max_size = 2M, upload_max_filesize = 8M
  • login.js file:
      $.ajax({
          type: "POST",
          url: "/php/login.php",
          data: {
            usernameData: "DaRealAdalbertBro",
            passwordData: "123"
          },
          cache: false,
          success: function(datas){
            $.each(datas, function(idx, loginData){
              console.log(loginData.name)
              console.log(loginData.password)
            });
          },
          error: function(xhr, status, error) {
          console.error(xhr.responseText);
          console.error(status);
          console.error(error);
          }
      });
  • login.php file in php folder:
    <?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

$servername = "AA";
$database = "BB";
$username = "CC";
$password = "DD";

$conn = new mysqli($servername, $username, $password, $database);

if ($conn->connect_error) {
  console.log("Connection failed: " . $conn->connect_error);
}


$mainusername = $_POST['usernameData'];
$mainpassword = $_POST['passwordData'];

$sql = "SELECT * FROM user WHERE username='$mainusername'";
$results = mysqli_query($conn, $sql);

$rawlogindata = array();
while ($row = mysqli_fetch_array($results)) {
  $arrayData = array(
    "name"         => $row['username'],
    "password"          => $row['pass']
  );
  $rawlogindata[] = $arrayData;
}

echo json_encode($rawlogindata);

mysqli_close($conn)
?>
  • my login.html form:
<form class="sign-in-form" action="login.php" method="POST" id="logform" autocomplete="off">
    
    <h2 class="title">Log in</h2>

    <div class="input-field">
        <i class="fas fa-user"></i>
        <input type="text" name="usernameData" placeholder="Username" minlength="4" maxlength="24" id="logusername" onfocusout="checkInputsUsernameLogin()" onkeyup="cleanUsername('logusername')" onkeydown="cleanUsername('logusername')" />
        <i class="erroricon fas fa-exclamation-circle"></i>
        <small class="form-login-message">Unknown Error - please contact the support.</small>
    </div>
    <div class="input-field">
        <i class="fas fa-lock"></i>
        <input type="password" name="passwordData" placeholder="Password" onpaste="return false;" ondrop="return false;" minlength="8" maxlength="255" id="logpassword" onfocusout="checkInputsPasswordLogin()" onkeyup="cleanPassword('logpassword')" onkeydown="cleanPassword('logpassword')" />
        <i class="erroricon fas fa-exclamation-circle"></i>
        <small>Unknown Error - please contact the support.</small>
    </div>

    <input type="submit" value="Login" class="btn solid" name="loginbutton" />
    

    <p class="social-text">Or Login with social platforms</p>


    <div class="social-media">
        <a href="#" class="social-icon">
            <i class="fab fa-discord"></i>
        </a>
        <a href="#" class="social-icon">
            <i class="fab fa-twitter"></i>
        </a>
        <a href="#" class="social-icon">
            <i class="fab fa-google"></i>
        </a>
        <a href="#" class="social-icon">
            <i class="fab fa-github"></i>
        </a>
    </div>
</form>
  • Also, if I change the $mainusername in /php/login.php to just a string, it works. Example: $mainusername = "DaRealAdalbertBro";

Thanks for all your responses,
Adalbert.

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    It's been a while, but I accidentally solved this problem a few days ago. On my VPS, I have a .htaccess file:

    RewriteCond %{THE_REQUEST} ^[A-Z]{3,}s([^.]+).php [NC]
RewriteRule ^ %1 [R=302,L]

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*?)/?$ $1.php [L]

    This code removes the .php suffix of the web URL. The problem was that I was sending these data to a file with the suffix. So the easy fix is to rewrite action="login.php" to just action="login", if you have this file as well.


  2. 0

    You have used $mainusername in login.php but you haven’t declared that. I guess you were trying to get the data from the form and select it. Your SQL Query is wrong. Please update that.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search