Add a custom orderby search in WooCommerce

问题

I would like to add a custom search order to my theme that will sort products by page views.

I already installed a Post Views Counter plugin to get the page views. Plugin documentation is available here.

I found following code on WooCommerce documentation:

add_filter( 'woocommerce_get_catalog_ordering_args', 'custom_woocommerce_get_catalog_ordering_args' );
function custom_woocommerce_get_catalog_ordering_args( $args ) {
  $orderby_value = isset( $_GET['orderby'] ) ? wc_clean( $_GET['orderby'] ) : apply_filters( 'woocommerce_default_catalog_orderby', get_option( 'woocommerce_default_catalog_orderby' ) );
    if ( 'random_list' == $orderby_value ) {
        $args['orderby'] = 'rand';
        $args['order'] = '';
        $args['meta_key'] = '';
    }
    return $args;
}
add_filter( 'woocommerce_default_catalog_orderby_options', 'custom_woocommerce_catalog_orderby' );
add_filter( 'woocommerce_catalog_orderby', 'custom_woocommerce_catalog_orderby' );
function custom_woocommerce_catalog_orderby( $sortby ) {
    $sortby['random_list'] = 'Random';
    return $sortby;
}

I allready tried:

add_filter( 'woocommerce_get_catalog_ordering_args', 'custom_woocommerce_get_catalog_ordering_args' );
function custom_woocommerce_get_catalog_ordering_args( $args ) {
  $orderby_value = isset( $_GET['orderby'] ) ? wc_clean( $_GET['orderby'] ) : apply_filters( 'woocommerce_default_catalog_orderby', get_option( 'woocommerce_default_catalog_orderby' ) );
    if ( 'most_viewed' == $orderby_value ) {
        $args['orderby'] = 'post_views';
        $args['order'] = 'DESC';
        $args['meta_key'] = '';
    }
    return $args;
}
add_filter( 'woocommerce_default_catalog_orderby_options', 'custom_woocommerce_catalog_orderby' );
add_filter( 'woocommerce_catalog_orderby', 'custom_woocommerce_catalog_orderby' );
function custom_woocommerce_catalog_orderby( $sortby ) {
    $sortby['most_viewed'] = 'Most viewed';
    return $sortby;
}

Hope someone knows how to change that function to work corectly.

来源：https://stackoverflow.com/questions/54523925/add-a-custom-orderby-search-in-woocommerce