WPMU Membership Card with shortcode

code.php

<?php
/*
* Use [my_mem_card] shorcode in anywhere in a page
*/
function my_mem_func() {
	if( is_user_logged_in() ){
		$current_user = wp_get_current_user();
		$factory = Membership_Plugin::factory();
		$user_object = $factory->get_member( $current_user->ID );
		$userlevels = $user_object->get_level_ids();
		if (!empty($userlevels)) {
			$rows = array();
			foreach ((array) $userlevels as $key => $value) {
			    $level = Membership_Plugin::factory()->get_level($value->level_id);
			    if (!empty($level)) {
				if ((int) $value->sub_id != 0) {
				    $rows[] = "<strong>" . $level->level_title() . "</strong>";
				} else {
				    $rows[] = $level->level_title();
				}
			    }
			} 
		    }
		$html = '<div class="mem_card">';
			$html .= $current_user->user_firstname . '<br>';
			$html .= $current_user->user_email . '<br>';
			$html .= $current_user->user_login . '<br>';
			$html .= 'Level: ' . implode(", ", $rows);;
		$html .= '</div>';
		return $html;
	}
	
}
add_shortcode('my_mem_card', 'my_mem_func');