Take a look at update_user_meta
you can save user data if they are registering or signed in, its just a matter of what user ID you pass to it.
say in your function to save the user data after he is logged in:
function save_user_data_7231(){
global $current_user;
if is_user_logged_in{ //check if user is logged in.
if (isset($_POST['Notes'])){
// get current user info
get_currentuserinfo();
$old_notes = get_user_meta($current_user->ID, 'user_notes', true);
if (isset($old_notes)&& is_array($old_notes)){
//if we saved already more the one notes
$old_notes[] = $_POST['Notes'];
update_user_meta( $current_user->ID, 'user_notes', $old_notes);
}
if (isset($old_notes)&& !is_array($old_notes)){
//if we saved only one note before
$new_notes = array($old_notes,$_POST['Notes']);
update_user_meta( $current_user->ID, 'user_notes', $new_notes)
}
if (!isset($old_notes)){
//first note we are saving fr this user
update_user_meta( $current_user->ID, 'user_notes', $_POST['Notes'])
}
}
}
}
they to display there notes you can use get_user_meta
function get_user_notes_654(){
global $current_user;
if is_user_logged_in{ //check if user is logged in.
// get current user info
get_currentuserinfo();
$old_notes = get_user_meta($current_user->ID, 'user_notes', true);
if (!isset($old_notes)){
$re = 'No Notes YET!';
}
if (isset($old_notes)){//we have notes. Removed the extra ! here.
if (is_array($old_notes)){//more then one
foreach($old_notes as $note){
$re .= '<strong>note:</strong>' . $note . '<br />';
}
}else{//just one
$re = '<strong>note:</strong>' . $old_notes . '<br />';
}
}
re .='//add note form would come here';
return $re;
}
}
Hope this Helps