CF7: Redirect to another URL if submission error - wordpress

Question

I have created a form using the Contact Form 7 plugin for WordPress.
My form looks like this:
<label> User Name*
[text* your-name] </label>
<label> Email Adress*
[email* your-email] </label>
[submit "Register"]
I can detect if someone trying to use the same email address (already registered) via this tutorial, https://cfdbplugin.com/?page_id=904
But, WHILE showing the error message, how can I let the page redirect him to another URL after some amount of time? For example to "/homesite/?para="
Maybe I need to do something with this code
if (is_already_submitted($formName, $fieldName, $_POST[$name])) {
$result->invalidate($tag, $errorMessage);
}
}
return $result;
But I don't know how should I amend those code. Please help me.

Answer 1

You can do this using DOM Events. CF7 has custom DOM events, which can be used to redirect users to other page. Since you want to redirect when form data is invalid, you will need to use wpcf7invalid event.
wpcf7invalid — Fires when an Ajax form submission has completed successfully, but mail hasn’t been sent because there are fields with invalid input.
A quick example:
function my_awesome_cf7_custom_events () { ?>
<script type="text/javascript">
document.addEventListener( 'wpcf7invalid', function( event ) {
if ( 'FORM_ID' == event.detail.contactFormId ) {//<===replace FORM_ID with form id
location.replace('https://your-new-url/');
}
}, false );
</script>
<?php }
add_action( 'wp_footer', 'my_awesome_cf7_custom_events' );
Replace FORM_ID with your form id, and set your url.
More about CF7 DOM events