I'm trying to authenticate a user using AJAX wrapped with jQuery to call a PHP script that queries a MySQL database. I'm NOT familiar with any of those technologies but I (sorta) managed to get them working individually, but I can't get the jQuery, AJAX and HTML to work properly.
[Edit:] I followed Trinh Hoang Nhu's advice and added a return false;
statement to disable the Submit button. All previous errors fixed, I can't get the object returned by the AJAX right.
HTML
Here's the HTML snippet I use:
<form id="form" method='post'>
<label>Username:</label>
<input id="user" name="user" type="text" maxlength="30" required /> <br />
<label>Password:</label>
<input id="pass" name="pass" type="password" maxlength="30" required /> <br />
<input id="url" name="url" type="text" value="<?php echo $_GET['url'] ?>" hidden />
<input name="submit" type="submit" value="I'm done">
</form>
jQuery/AJAX
Here's my jquery code for using AJAX to authenticate a user (sorry if the indenting is messed up because of the tabs):
function changeMessage(message) {
document.getElementById("message").innerHTML = message; }
$(document).ready(function() {
$("#form").submit(function() {
changeMessage("Checking");
//check the username exists or not from ajax
$.post("/stufftothink/php/AJAX/login.php",
{user: $("#user").val(), pass: $("#pass").val(), url: $("#url") },
function(result) {
//if failed
if (result === 'false') {
changeMessage("Invalid username or password. Check for typos and try again");
$("#pass").val(""); }
//if authenticated
else {
changeMessage("Authenticated");
window.location.href = result; }
} );
//to disable the submit button
return false;
} );
} )
PHP
And here's my PHP script that gets called:
<?php
ob_start();
session_start();
$user = $_POST['user'];
$pass = md5($_POST['pass']);
mysql_connect('localhost', 'root', '');
mysql_select_db('stufftothink');
$query = "select * from users where user = '$user' and pass = '$pass'";
$result = mysql_query($query);
$i = 0;
while ($row = mysql_fetch_array($result)) {
$i = 1; }
if ($i == 1) {
$_SESSION['user'] = $user;
$invalid_urls = array('register.php', 'login.php');
$url = $_REQUEST['url']; //not sure whether _GET or _POST
if (in_array($url, $invalid_urls)) {
echo '/stufftothink/profile.php'; }
else {
echo '/stufftothink/'.$url; }
}
else {
echo 'false'; }
mysql_close();
?>
Edit
I've been getting a lot of downvotes on this question. I had accidentally submitted the question without the explanation filled in. I went back to edit it, but when I came back, there were already 4 downvotes. It had barely been a couple of minutes. Am I doing something wrong, or were the first 5 minutes the problem?