How to get an error message if a form is empty (plugin: Post for site) [closed]

You’ve already got a check for $_POST == empty.

**if (!empty($_POST)){
$pfs = pfs_submit($_POST,$_FILES);
echo json_encode($pfs);
//echo "<pre style=\"border:1px solid #ccc;margin-top:5px;\">".print_r($pfs, true)."\n";
wp_redirect("http://domda.se/tack/");
exit;
} else {
/* TODO: translate following */
_e('Den här sidan hade du inte behövt se, något är fel.','pfs_domain');
echo "<a href="".get_bloginfo("url')."'>" . __('Go home?','pfs_domain') . "</a>";
}**

Add an error handler there. You will need to pass a parameter through wp_redirect …

wp_redirect("http://domda.se/tack/?myerror=error-code");

And process it on the receiving page…

if (isset($_GET['myerror'])) {
  // do stuff
}