Insert PHP code via shortcode?
$current_user isn’t declared in the scope of that function. You’d want to modify the code to be more like this: function get_form($atts) { $current_user = wp_get_current_user(); return ‘<form method=”post” action=””> <input type=”input” name=”myinput” value=””></input> <input type=”hidden” name=”myvar” value=”‘ . $current_user->ID . ‘”> </form>’; } add_shortcode(‘myshortcode’, ‘get_form’);