wc-emails-classic

WooCommerce classic transactional emails

Choose the smallest extension point:

1. Change markup only: override a template in the theme.
2. Change existing email values: use settings or a targeted filter.
3. Add a new notification type: extend WC_Email and register it.

Template override

your-theme/woocommerce/emails/customer-processing-order.php
your-theme/woocommerce/emails/plain/customer-processing-order.php

Copy from WooCommerce's templates/emails tree and preserve the template version header. Theme overrides win over plugin/core templates and must be reviewed when WooCommerce reports them outdated.

For a plugin-owned custom email, set:

$this->template_base = MYPLUGIN_PATH . 'templates/';

Users can still override that template through the theme's woocommerce/ directory.

Custom email class

namespace MyPlugin\Email;

final class ShipmentReadyEmail extends \WC_Email {
    public function __construct() {
        $this->id             = 'myplugin_shipment_ready';
        $this->customer_email = true;
        $this->title          = __( 'Shipment ready', 'myplugin' );
        $this->description    = __( 'Sent when a shipment becomes ready.', 'myplugin' );
        $this->template_html  = 'emails/shipment-ready.php';
        $this->template_plain = 'emails/plain/shipment-ready.php';
        $this->template_base  = MYPLUGIN_PATH . 'templates/';

        $this->placeholders = array(
            '{order_number}' => '',
            '{order_date}'   => '',
        );

        add_action( 'myplugin_shipment_ready_notification', array( $this, 'trigger' ), 10, 2 );

        // Parent needs the stable ID and template properties to load settings.
        parent::__construct();

        // Properties depending on parent feature flags belong after this point.
    }

    public function get_default_subject(): string {
        return __( 'Order {order_number} is ready to ship', 'myplugin' );
    }

    public function get_default_heading(): string {
        return __( 'Your shipment is ready', 'myplugin' );
    }

    public function trigger( $order_id, $order = false ): void {
        $this->setup_locale();

        try {
            if ( $order_id && ! $order instanceof \WC_Order ) {
                $order = wc_get_order( $order_id );
            }

            if ( ! $order instanceof \WC_Order ) {
                return;
            }

            $this->object                         = $order;
            $this->recipient                      = $order->get_billing_email();
            $this->placeholders['{order_number}'] = $order->get_order_number();
            $this->placeholders['{order_date}']   = wc_format_datetime( $order->get_date_created() );

            // WC 10.9 standard guard: enabled + recipient + outcome hooks.
            $this->send_notification();
        } finally {
            $this->restore_locale();
        }
    }

    public function get_content_html(): string {
        return wc_get_template_html(
            $this->template_html,
            $this->template_args( false ),
            '',
            $this->template_base
        );
    }

    public function get_content_plain(): string {
        return wc_get_template_html(
            $this->template_plain,
            $this->template_args( true ),
            '',
            $this->template_base
        );
    }

    private function template_args( bool $plain ): array {
        return array(
            'order'              => $this->object,
            'email_heading'      => $this->get_heading(),
            'additional_content' => $this->get_additional_content(),
            'sent_to_admin'      => false,
            'plain_text'         => $plain,
            'email'              => $this,
        );
    }
}