WooCommerce: Link external products to detail product page from product category list

gistfile1.txt

add_filter( 'woocommerce_loop_add_to_cart_link', 'product_cat_external', 10, 2 );

function product_cat_external( $html, $product ) {
	if ( $product->product_type === 'external' ) {
		return '<a href="' . get_post_permalink( $product->id ) . '" rel="nofollow" data-product_id="' . esc_attr( $product->id ) . '" data-product_sku="' . esc_attr( $product->get_sku() ) . '" class="button add_to_cart_button product_type_variable">View Detail</a>';
	} else {
		return $html;
	}
}