Redirecting or displaying a message on first login

Question

I've been trying to decipher a way to display a message to a user on first login and can't seem to get it to work. I'm not sure what I'm missing, or if there's something else I need to do. Any help would be appreciated. I feel like I missing something here.

function ap_new_user_message() {
    $current_user = wp_get_current_user();
    $user_ID = $current_user->ID;
    //global $user_ID;
    if( $user_ID ) {
        $user_info = get_userdata( $user_ID );
        // If user_registered date/time is less than 48hrs from now
        // Message will show for 48hrs after registration
        if ( strtotime( $user_info->user_registered ) > ( time() - 172800 ) )
        echo '<div>display a message</div>';
    }
}

Alternatively, If I could find a way of determining how many days it's been since a user was created I could do something similar. Perhaps by adding to the user meta table?

function first_login($login) {
    global $user_ID;
    $user = get_userdatabylogin($login);
    update_usermeta( $user->ID, 'first_login', date(), time() );
  }
add_action('wp_login','first_login');

And then calling for it

if first_login(date, time) == (today, ago) {
#do something
}

Update: Milo's code worked great. However, I needed it to work with Eric Meyer's Simple Modal Login. I found this function within simplemodal-login.php and peter's login redirect.

        function login_redirect($redirect_to, $req_redirect_to, $user) {
        if (!isset($user->user_login) || !$this->is_ajax()) {
            return $redirect_to;
        }
        if ($this->is_plugin_active('peters-login-redirect/wplogin_redirect.php')
                && function_exists('redirect_to_front_page')) {
            $redirect_to = redirect_to_front_page($redirect_to, $req_redirect_to, $user);
        }
        echo "<div id='simplemodal-login-redirect'>$redirect_to</div>";
        exit();
    }

and added Milo's redirect to it like so:

    function login_redirect($redirect_to, $req_redirect_to, $user) {
        $regtime = strtotime($user->user_registered);
        $now = strtotime("now");
        $diff = $now - $regtime;
        $hours = $diff / 60 / 60;
        if (!isset($user->user_login) || !$this->is_ajax()) {
            return $redirect_to;
        }
        if ($this->is_plugin_active('peters-login-redirect/wplogin_redirect.php')&& function_exists('redirect_to_front_page')) {
            $redirect_to = redirect_to_front_page($redirect_to, $req_redirect_to, $user);
        }
        if( $hours < 48 ){
            $redirect_to = "/somepage/"; // it's been less than 48 hours, redirect to message.
        }
        echo "<div id='simplemodal-login-redirect'>$redirect_to</div>";
        exit();
    }

Now I just need to determine how to force a model popup when a users reaches a certain page.

Answer 1

here's an example that hooks login_redirect and checks when their account was created, then redirects them to a url of your choice if it's been less than 48 hours:

function my_redirect( $to, $requested, $user ){
    if( !isset( $user->user_login ) ){ // we only want this to run when credentials have been supplied
        return $to;
    }
    $regtime = strtotime($user->user_registered);
    $now = strtotime("now");
    $diff = $now - $regtime;
    $hours = $diff / 60 / 60;
    if( $hours < 48 ){
        return "/somepage/"; // it's been less than 48 hours, redirect to message.
    } else {
        return admin_url();
    }
}
add_filter('login_redirect', 'my_redirect', 10, 3);

Answer 2

You can use log-user-access plugin to log all user accesses.

Then, select the top row from each "login_id" from the plugin table sorted by date and time. That will be the user first login. With this data, you should be able to figure out the rest.