Register a new column that will show if an order was a first order for a customer - Woocommerce

register-a-new-column-that-will-show-if-an-order-was-a-first-order-for-a-customer-woocommerce.php

<?php
// Register a new column that will show if an order was a first order for a customer
add_filter( 'manage_edit-shop_order_columns', 'register_is_first_order_column', 10, 1 );
function register_is_first_order_column( $columns ) {
	$columns['is_first_order'] = 'Primo ordine';
	return $columns;
}

// Show a checkmark emoji in the column if it's true
add_action( 'manage_shop_order_posts_custom_column', 'display_is_first_order_column', 10, 1 );
function display_is_first_order_column( $column ) {
	global $post;

	if ( 'is_first_order' === $column ) {
		$is_first_order = get_post_meta( $post->ID, 'is_first_order', true );
	
		if ( false !== $is_first_order && strlen( $is_first_order ) > 0 ) {
			echo "✔️";
		}
	}
}

// Display our custom checkbox near the default WooCommerce filter options
add_action( 'restrict_manage_posts', 'show_is_first_order_checkbox' );
function show_is_first_order_checkbox() {
	?>

	<label>
		Solo i primi ordini
		<input type="checkbox" name="is_first_order" id="is_first_order" <?php echo isset( $_GET['is_first_order'] ) ? 'checked' : ''; ?>>
	</label>

	<?php
}

// Modify a query if the checkbox was checked
add_action( 'pre_get_posts', 'filter_woocommerce_orders_in_the_table', 99, 1 );
function filter_woocommerce_orders_in_the_table( $query ) {
	if ( ! is_admin() ) {
		return;
	}
	
	global $pagenow;

	if ( 'edit.php' === $pagenow && 'shop_order' === $query->query['post_type'] ) {
		
		// We don't need to modify a query if a checkbox wasn't checked
		if ( ! isset( $_GET['is_first_order'] ) ) {
			return $query;
		}
		
		$meta_query = array(
			array(
				'key' => 'is_first_order',
				'value' => 1,
				'compare' => '='
			)
		);
		
		$query->set( 'meta_query', $meta_query );
	}
	
	return;
}