ACF Options page - pick page parent of a CPT

acf-options-page-parent-cpt

// Set page parents of Custom Post Types - in the Organisation Setting ACF Options page
// Based upon Joe Sexton's blog post http://www.webtipblog.com/setting-wordpress-custom-post-type-parent-specific-page/
 
define( 'FRIENDS_PARENT_ID', get_field( 'friends_parent_page', 'option' ) );
 
add_action( 'wp_insert_post_data', 'biscuit_cpt_parent_page', '99', 2  ); 
 
function biscuit_cpt_parent_page( $data, $postarr ) {
    global $post;

    // if ( !wp_verify_nonce( $_POST['staff_parent_custom_box'], 'stc_cpt' ) )
    //     return $data;
 
    // verify if this is an auto save routine.
    // If it is our form has not been submitted, so we dont want to do anything
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
        return $data;
 
    if ( $post->post_type == "friends" ){
	    $data['post_parent'] = FRIENDS_PARENT_ID ;
	}
 
    return $data;
}