woothemes/woocommerce — pull request #4094 by robdvr (2013-11-12 21:20:16+00:00)
Title: Ability to add custom input classes

This makes it easier to add multiple custom classes to text fields and text areas.

Example with using bootstrap forms:

```
add_filter('woocommerce_billing_fields', 'custom_woocommerce_billing_fields');

function custom_woocommerce_billing_fields( $fields ) {
$fields['billing_address_1']['class'] = array( 'form-group' );
$fields['billing_address_1']['input_class'] = array( 'form-control' );
return $fields;
}
```