Lazy load WooCommerce WC_Countries patch - proof of concept.

lazy-load-WC_Countries.diff

Index: classes/class-wc-countries.php
===================================================================
--- classes/class-wc-countries.php	(revision 799848)
+++ classes/class-wc-countries.php	(working copy)
@@ -1,4 +1,30 @@
 <?php
+
+class WC_Countries_Loader {
+
+	private $instance;
+
+	private function get_instance() {
+		if ( empty( $this->instance ) ) {
+			$this->instance = new WC_Countries();
+		}
+
+		return $this->instance;
+	}
+
+	public function __get( $name ) {
+		return $this->get_instance()->{$name};
+	}
+
+	public function __set( $name, $value ) {
+		$this->get_instance()->{$name} = $value;
+	}
+
+	public function __call( $func, $args ) {
+		return call_user_func_array( array( $this->get_instance(), $func ), $args );
+	}
+}
+
 /**
  * WooCommerce countries
  *
Index: woocommerce.php
===================================================================
--- woocommerce.php	(revision 799848)
+++ woocommerce.php	(working copy)
@@ -477,7 +477,7 @@
 
 		// Load class instances
 		$this->product_factory 		= new WC_Product_Factory();     // Product Factory to create new product instances
-		$this->countries 			= new WC_Countries();			// Countries class
+		$this->countries 			= new WC_Countries_Loader();	// Countries class
 		$this->integrations			= new WC_Integrations();		// Integrations class
 
 		// Classes/actions loaded for the frontend and for ajax requests
@@ -1201,7 +1201,6 @@
 
 		// Variables for JS scripts
 		$woocommerce_params = array(
-			'countries'                        => json_encode( $this->countries->get_allowed_country_states() ),
 			'plugin_url'                       => $this->plugin_url(),
 			'ajax_url'                         => $this->ajax_url(),
 			'ajax_loader_url'                  => apply_filters( 'woocommerce_ajax_loader_url', $this->plugin_url() . '/assets/images/ajax-loader@2x.gif' ),
@@ -1221,8 +1220,10 @@
 			'cart_redirect_after_add'          => get_option( 'woocommerce_cart_redirect_after_add' )
 		);
 
-		if ( is_checkout() || is_cart() )
+		if ( is_checkout() || is_cart() ) {
+			$woocommerce_params['countries'] = json_encode( $this->countries->get_allowed_country_states() );
 			$woocommerce_params['locale'] = json_encode( $this->countries->get_country_locale() );
+		}
 
 		wp_localize_script( 'woocommerce', 'woocommerce_params', apply_filters( 'woocommerce_params', $woocommerce_params ) );