Simple dropdown field which displays a text field when 'Other' is selected. Great for Honorific selects.
Add the dropdown options to the _config/AlternativeFormField.yml file.
You can also edit the empty string for the dropdown and the label for the 'other' field in the yml.
SilverStripe 3.0 or higher is required.
<?php
public function getCMSFields() {
$fields = parent::getCMSFields();
$fields->addFieldsToTab("Root.Whatever", array(
AlternativeFormField::create('Honorific', 'Honorific'),
TextField::create('FirstName', 'First name'),
TextField::create('Surname', 'Last name')
));
return $fields;
}