This example is for form id 17. It adds a new option to fields 23 and 24, that only a logged in user can see.
add_filter( 'gform_pre_render_17', 'populate_posts' );
add_filter( 'gform_pre_validation_17', 'populate_posts' );
add_filter( 'gform_pre_submission_filter_17', 'populate_posts' );
add_filter( 'gform_admin_pre_render_17', 'populate_posts' );
function populate_posts( $form ) {
foreach ( $form['fields'] as &$field ) {
if ( $field->id == '23' || $field->id == '24') {
$choices = array();
$choices[] = array( 'text' => '', 'value' => '' );
$choices[] = array( 'text' => 'No', 'value' => 'No' );
$choices[] = array( 'text' => 'Yes', 'value' => 'Yes' );
if (is_user_logged_in() ) {
$choices[] = array( 'text' => 'Yes - CONFIRMED', 'value' => 'Yes - CONFIRMED' );
}
$field->choices = $choices;
}
}
return $form;
}