What is best approach to update the user info in custom component user-info table?

Question

I have developed a custom component that store some user information in separate tables, I want to store/update user information when user deleted or updated from admin section or front end.

Answer 1

You should save your data using a User Plugin - they're very easy to write. An example can be found at Creating a profile plugin, though the example might have more than you need.

The events your code would go into are onUserAfterSave and onUserAfterDelete and are documented at Plugin/Events/User. These events will fire when a user is saved or deleted in the admin or Front-end.

The guts of the plugin would be this:

defined('_JEXEC') or die;
class PlgUserMyPlugin extends JPlugin
{
    protected $app;
    protected $db;

    public function onUserAfterDelete($user, $success, $msg) {
        if (!$success) 
            return false;

        $query = $this->db->getQuery(true)
        ->delete($this->db->quoteName('#__mytable'))
        ->where($this->db->quoteName('userid') . ' = ' . (int) $user['id']);
        $this->db->setQuery($query)->execute();
        return true;
    }

    public function onUserAfterSave($user, $isnew, $success, $msg) {
        if (!$success) 
            return false;

        // Update your table here
        if ($isnew) {
            // New User
        }else{
            // Existing User
        }
    }
}