Page one contains an HTML form. Page two - the code that handles the submitted data.
The form in page one gets submitted. The browser gets redirected to page two. Page two handles the submitted data.
At this point, if page two gets refreshed, a "Confirm Form Resubmission" alert pops up.
Can this be prevented?
You can use replaceState method of JQuery:
<script>
$(document).ready(function(){
window.history.replaceState('','',window.location.href)
});
</script>
This is the most elegant way to prevent data again after submission due to post back.
Hope this helps.
Try tris:
function prevent_multi_submit($excl = "validator") {
$string = "";
foreach ($_POST as $key => $val) {
// this test is to exclude a single variable, f.e. a captcha value
if ($key != $excl) {
$string .= $key . $val;
}
}
if (isset($_SESSION['last'])) {
if ($_SESSION['last'] === md5($string)) {
return false;
} else {
$_SESSION['last'] = md5($string);
return true;
}
} else {
$_SESSION['last'] = md5($string);
return true;
}
}
How to use / example:
if (isset($_POST)) {
if ($_POST['field'] != "") { // place here the form validation and other controls
if (prevent_multi_submit()) { // use the function before you call the database or etc
mysql_query("INSERT INTO table..."); // or send a mail like...
mail($mailto, $sub, $body); // etc
} else {
echo "The form is already processed";
}
} else {
// your error about invalid fields
}
}
Font: https://www.tutdepot.com/prevent-multiple-form-submission/
use js to prevent add data:
if ( window.history.replaceState ) {
window.history.replaceState( null, null, window.location.href );
}