product_type == "variation")
$product_parent_id=wp_get_post_parent_id( $product_id);
else
$product_parent_id=$product_id;
$products_metas =get_post_meta($product_parent_id,'shipping-date-start',true);
if(isset($products_metas[$product_id]) && !empty($products_metas[$product_id]) && $products_metas[$product_id]>date('Y-m-d')){
echo apply_filters( 'woocommerce_loop_add_to_cart_link',
sprintf( '%s',
esc_url( $product->add_to_cart_url() ),
esc_attr( isset( $quantity ) ? $quantity : 1 ),
esc_attr( $product->id ),
esc_attr( $product->get_sku() ),
esc_attr( isset( $class ) ? $class.' grand_popo-preorder' : 'button' ),
esc_html( "Pre order", "grand-popo" )
),
$product );
}else{
echo apply_filters( 'woocommerce_loop_add_to_cart_link',
sprintf( '%s',
esc_url( $product->add_to_cart_url() ),
esc_attr( isset( $quantity ) ? $quantity : 1 ),
esc_attr( $product->id ),
esc_attr( $product->get_sku() ),
esc_attr( isset( $class ) ? $class : 'button' ),
esc_html( $product->add_to_cart_text() )
),
$product );
}