The `addExtraClass` is a method in PHP's DropdownField class. It allows you to add one or more CSS classes to the output HTML element of a dropdown field in a webpage. This method can be useful when you want to customize the appearance or style of a dropdown field by applying different CSS classes to it.
PHP DropdownField::addExtraClass - 28 examples found. These are the top rated real world PHP examples of DropdownField::addExtraClass extracted from open source projects. You can rate examples to help us improve the quality of examples.