How to observe event before saveShipping or saveBilling actions for address validation

Update: For my understanding (please correct me If I am wrong) the problem here is that the controller_action_predispatch_checkout_onepage_saveBilling gets dispatched and the following code is being executed (from Mage.php): public static function dispatchEvent($name, array $data = array()) { Varien_Profiler::start(‘DISPATCH EVENT:’.$name); $result = self::app()->dispatchEvent($name, $data); Varien_Profiler::stop(‘DISPATCH EVENT:’.$name); return $result; } the Object of type Mage_Core_model_Appthat is…

How to make Customer Billing Phone Number Unique Validation in WordPress

Actually I want customers to add unique-phone numbers in the billing address of woo-commerce. I tried the below code but it is not working. Can anyone give me the correct code for unique phone numbers in Woocommerce? add_action( ‘woocommerce_register_form’, ‘wooc_Phone_fields’ ); function wooc_phone_fields ($username, $email, $errors ) { if ( isset( $_POST[‘billing_phone’] ) ) {…