Check the plugin code for usage.
Don't get overwhelmed! Most of the file in this repo is related to unit testing or integrated build
.
Following files are all need to get this running :
woo-add-shipping-class/
├── class-custom-woo-shipping-class-fields.php (your intrested code)
└── init.php (plugin main file)
STEP 1 - Display Field Name in Header
//loc: woocommerce/includes/admin/settings/class-wc-settings-shipping.php #adding coulmns to list header
apply_filter('woocommerce_shipping_classes_columns', $shipping_columns_array) ;
STEP 2 - Display Fields
//loc: woocommerce/includes/admin/settings/views/html-admin-page-shipping-classes.php
do_action('woocommerce_shipping_classes_column_'.$class)
STEP 3 - Update the database with the values set
//loc: woocommerce/includes/class-wc-ajax.php #function to add/update shipping class metas value
do_action('woocommerce_shipping_classes_save_class', $term_id, $data);
STEP 4 - Modify shipping class object to add these fields' data before localization
//loc: woocommerce/includes/class-wc-shipping.php #function to modified localized shipping class data
apply_filter('woocommerce_get_shipping_classes', $shipping_classes);