PDF template filter hooks

The template engine of PDF Invoices & Packing slips is built for flexibility, and includes a list of filter hooks that you can use to manipulate different types of data.

The template engine of PDF Invoices & Packing slips is built for flexibility, and includes a list of filter hooks that you can use to manipulate different types of data.

Using the template filter hooks #

Using filter hooks is not that difficult as it sounds, it’s a simple way for you to manipulate data without dealing with complicated functions or plugin core code. Unlike action hooks, filters always return the first argument data, and because of that you can manipulate that data before returning it. If you never worked with filters you can read this documentation page about how to use filters.

Filter scripts usually live inside functions.php, a file that comes inside any WordPress theme. You can choose to modify that file directly in the main theme (not recommended), within a child-theme or through a plugin like Code Snippets.

Example 1: Sort document order items by category #

This little snippet will sort the document order items by category.

add_filter( 'wpo_wcpdf_order_items_data', 'wpo_wcpdf_sort_items_by_category', 10, 2 );
function wpo_wcpdf_sort_items_by_category ( $items, $order ) {
    usort($items, function( $a, $b ) {
        return strcmp(wc_get_product_category_list( $a['product']->get_id()), wc_get_product_category_list( $b['product']->get_id()));
    });
 
    return $items;
}

Example 2: Hide specific products on packing slip #

This little snippet will hide specific products (indicated by ID) from the packing slip document.

add_filter( 'wpo_wcpdf_order_item_data', 'wpo_wcpdf_hide_products_packing_slip', 10, 3 );
function wpo_wcpdf_hide_products_packing_slip( $data, $order, $document_type )
{
    $products_ids_to_hide = array(16, 23); // include here your product IDs
 
    if ($document_type == 'packing-slip') { // you can replace with 'invoice' or any other document type
 
        if( in_array($data['product_id'], $products_ids_to_hide) ) {
            $data['name'] = null;
            $data['quantity'] = null;
        }
 
    }
 
    return $data;
}

Example 3: Disallow document on order custom field #

This little snippet will disallow a document creation if a specified custom field is found in the order.

add_filter('wpo_wcpdf_document_is_allowed', 'disallow_document_on_custom_field', 10, 2);
function disallow_document_on_custom_field( $allowed, $document )
{
    $order = $document->order;
 
    if ( !empty($order) && $document->get_type() == 'custom-template' ) { // replace 'custom-template' with your custom template name or default names like 'invoice', 'packing-slip', etc.
 
        $order_meta = $order->get_meta('gift_message'); // replace 'gift_message' with you own custom field name
 
        if( !$order_meta || $order_meta == '' ) {
            $allowed = false;
        }
 
    }
    return $allowed;
}