Add InvoiceXpress documents to WooCommerce order list

woocommerce_ixpro_invoice_order_list.php

<?php
add_filter( 'manage_edit-shop_order_columns', 'woocommerce_ixpro_invoice_order_list_column_header' );
function woocommerce_ixpro_invoice_order_list_column_header( $columns ) {
	$columns['ixpro_docs'] = __( 'InvoiceXpress', 'webdados-toolbox' );
	return $columns;
}
add_action( 'manage_shop_order_posts_custom_column', 'woocommerce_ixpro_invoice_order_list_column_value' );
function woocommerce_ixpro_invoice_order_list_column_value( $column ) {
	global $post;
	if ( 'ixpro_docs' === $column ) {
		if ( $order = wc_get_order( $post->ID ) ) {
			$issued_documents = array();
			$documents = array(
				'invoice'            => __( 'Invoice', 'woo-billing-with-invoicexpress' ),
				'simplified_invoice' => __( 'Simplified invoice', 'woo-billing-with-invoicexpress' ),
				'invoice_receipt'    => __( 'Invoice-receipt', 'woo-billing-with-invoicexpress' ),
				'credit_note'        => __( 'Credit note', 'woo-billing-with-invoicexpress' ),
				'receipt'            => __( 'Receipt', 'woo-billing-with-invoicexpress' ),
				'quote'              => __( 'Quote', 'woo-billing-with-invoicexpress' ),
				'proforma'           => __( 'Proforma', 'woo-billing-with-invoicexpress' ),
				'transport_guide'    => __( 'Delivery note', 'woo-billing-with-invoicexpress' ),
				'devolution_guide'   => __( 'Return delivery note', 'woo-billing-with-invoicexpress' )
			);
			foreach ( $documents as $doc => $label ) {
				$docref = $order->get_meta( 'hd_wc_ie_plus_'.$doc.'_sequence_number' );
				if ( empty( $docref ) ) $docref = $order->get_meta( 'hd_wc_ie_plus_'.$doc.'_id' ); //Backward compatibility
				if ( ! empty( $docref ) ) {
					$issued_documents[] = $doc;
					if ( ! $link = $order->get_meta( 'hd_wc_ie_plus_'.$doc.'_pdf' ) ) {
						$link = $order->get_meta( 'hd_wc_ie_plus_'.$doc.'_permalink' );
					}
					echo '<div style="line-height: 1em; margin-bottom: 0.25em;"><small>'.$label.': <strong><a href="'.esc_url( $link ).'" target="_blank">'.$docref.'</a></strong></small></div>';
				}
			}
		}
	}
}