Display an admin notice after a term creation in WordPress - ajax

Question

I do not understand how to display a notice after a term creation in WordPress.
I have a custom field in a custom taxonomy. On the save event, I check if the value is incorrect and in this case, I want to display a notice.
I have a similar situation in the post editor but here I have solved with add_settings_error and admin_notices.
This method does not work in the term creation screen because in this scenario, there is an AJAX request and the page does not reload.
Here is the code about term screen:
add_action('create_account', 'save_start_amount_data__fr');
add_action('admin_notices', 'display_start_amount_data_validation_error__fr');
function save_start_amount_data__fr($term_id) {
if (
!isset($_POST['start_amount_nonce']) ||
!wp_verify_nonce($_POST['start_amount_nonce'], 'start_amount_nonce')
) {return $term_id;}
if (
(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)
) {return $term_id;}
if (
!isset($_POST['taxonomy']) ||
$_POST['taxonomy'] != 'account' ||
!current_user_can('edit_posts')
) {return $term_id;}
if (
!isset($_POST['start_amount'])
) {return $term_id;}
if (
!preg_match('/^[-]?[0-9]+([,]?[0-9]{1,2})?$/', $_POST['start_amount'])
) {validate_start_amount_data__fr();}
$start_amount = $_POST['start_amount'];
$start_amount = sanitize_text_field($start_amount);
update_term_meta($term_id, 'start_amount', $start_amount);
return $term_id;
}
function validate_start_amount_data__fr() {
add_settings_error(
'incorrect_start_amount_value',
'incorrect_start_amount_value',
__('Please review the start amount value because it is in an incorrect format.', 'fr'),
'error'
);
set_transient('settings_errors', get_settings_errors(), 30);
return null;
}
function display_start_amount_data_validation_error__fr() {
$errors = get_transient('settings_errors');
if (!$errors) {return null;}
$message = '<div class="notice notice-error"><ul>';
foreach($errors as $error) {
$message .= '<li>' . $error['message'] . '</li>';
}
$message .= '</ul></div>';
echo $message;
delete_transient('settings_errors');
remove_action('admin_notices', 'display_start_amount_data_validation_error__fr');
return null;
}
I hope that someone can help me to achieve my goal.

Answer 1

See below the method that I'm using on a Custom Posts to display notifications.
Take a look to the filter "redirect_post_location".
//Actions
$this->loader->add_action( 'admin_notices', $plugin_admin, 'general_admin_notice' );
$this->loader->add_action( 'save_post', $plugin_admin, 'admin_save_post' );
/**
* Admin Save the Meta box values
*
* #since 1.0.0
*/
function admin_save_post( $id ) {
/* --- security verification --- */
if(!wp_verify_nonce($_POST['attachment_nonce'], plugin_basename(__FILE__))) {
return $id;
} // end if
if(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
return $id;
} // end if
if('page' == $_POST['post_type']) {
if(!current_user_can('edit_page', $id)) {
return $id;
} // end if
} else {
if(!current_user_can('edit_page', $id)) {
return $id;
} // end if
} // end if
/* - end security verification - */
// Make sure the file array isn't empty
if(!empty($_FILES['secure_doc_attachment']['name'])) {
$upload = $this->admin_upload_file( $_FILES , $id );
if (!$upload){
add_filter('redirect_post_location', function($loc) {
return add_query_arg( 'error', 1, $loc );
});
return $post_id;
}
}
}
/**
* Admin Notice
*
* #since 1.0.0
*/
function general_admin_notice(){
global $pagenow;
if ( 'post.php' === $pagenow && isset($_GET['post']) && 'custom-post' === get_post_type( $_GET['post'] ) ){
if ( isset($_GET['error'])) {
echo '<div class="notice notice-error is-dismissible">
<p>Error uploading the attachment.</p>
</div>';
}
}
}
See other useful link here:
https://wordpress.stackexchange.com/questions/124132/admin-post-update-redirection-to-posts-screen
Regards.
Ed.