ajax调用后文本框不清除

Question

I have this chat room on my website, where the user types their message into a textbox and when they press enter (or the send button), jQuery takes the data from the textbox, disables the textbox, sends the data to the file send.php where it is then processed and put into the database, and then it should clear and undisable the textbox once it successfully runs through the PHP script. What is happening is the data is being submitted and it runs through the script (sends the data to the database successfully) but the jQuery is not clearing and undisabling the textbox. Can someone explain to me what is wrong?

jQuery:

$('#formSend').on('submit', function (e) {

    e.preventDefault();

    var textArea = document.getElementById('styled');

    if( textArea.value != "" ) {

        var formData = $('form').serialize();
        $('.expand').prop("disabled", true)

        $.ajax({
            type: 'post',
            url: 'send.php',
            data: formData,
            dataType: "json",
            success: function (formData) { //put data in parentheses when coming back
                alert("Success");
                $(".expand").val('');
                $('.expand').prop("disabled", false);

                if( formData["banned"] == 1 ) {
                    var rel = confirm("You have been banned.");
                    if (rel) {
                        location.reload();
                    }
                    else {
                        location.reload();
                    }
                }
            }
        });
    }
    else {
        alert("Your message must be longer than 1 (one) character.");
        $('#styled').focus();
    }
});

send.php:

<?php

include("../config.php");
session_start();


$msg           = strip_tags( $_POST['msg'], '<b></b>' );

if( $msg == "" ) {
 exit("There is no message.");
}
$username      = $_SESSION['USER'];
$date          = new DateTime();
$formattedDate = $date->format('Y-m-d H:i:s');

$stmt = $db->prepare("SELECT id, username FROM users WHERE username = :username");

$stmt->execute(array(":username" => $username));

$row = $stmt->fetch();

$userID = $row['id'];

$checkBanned = $db->prepare('SELECT banned FROM users WHERE username = :username');
$checkBanned->execute(array(
            ':username' => $username
        ));
$banned = $checkBanned->fetch();

if( $banned['banned'] == "yes" ) {
    $return = array('banned' => 1);
    echo json_encode($return);
    exit;
}

try {

    $stmt = $db->prepare('INSERT INTO `chat-messages` (userID,msg,date) VALUES (:userID, :msg, :date)');
    $stmt->execute(array(
        ':userID' => $userID,
        ':msg' => $msg,
        ':date' => $formattedDate
    ));
}
catch(PDOException $e) {
    echo $e->getMessage();
}
?>

Here is the form too, if needed.

<form action="send.php" method="post" name="formSend" id="formSend" />
     <textarea id="styled" class="expand" name="msg" placeholder="Your Message Here" onfocus:"setbg(\'#e5fff3\');"required></textarea>
     <input type="hidden" name="banned" value="no" />
     <input type="submit" name="submit" value="Send" class="send" />

  </form>

Answer 1

Have you tried something like:

$('.expand').removeAttr("disabled");