Building a WooCommerce Custom Plugin: Step by Step

Plugin File Structure

Create a folder in wp-content/plugins/ and add a main PHP file with plugin headers. Organise code in class files or include files. Always check for WooCommerce before registering hooks so your plugin fails gracefully if WooCommerce is deactivated.

WooCommerce Action and Filter Hooks

WooCommerce exposes hundreds of hooks. woocommerce_checkout_fields lets you add custom checkout fields. woocommerce_order_status_changed triggers when order status changes. woocommerce_product_tabs adds content tabs to product pages.

Saving and Displaying Custom Data

Save custom checkout field values using the woocommerce_checkout_order_created hook and update_post_meta. Display them in the order admin with woocommerce_admin_order_data_after_billing_address and get_post_meta.

Custom Order Statuses

Register custom order statuses with register_post_status() and add them to WooCommerce with the wc_order_statuses filter. Add custom status colours in the admin by hooking into woocommerce_admin_order_preview_actions.