InheritanceField

gistfile1.php

// .. InheritableField.php
public function __construct($key, Field $field)
    {
        parent::__construct($key, array());

        $this->setPropertyPath('inheritanceData');

        $field->setKey('value');
        $field->setPropertyPath(sprintf('[%s][value]', $key));

        $checkboxField = new CheckboxField('inherit');
        $checkboxField->setPropertyPath(sprintf('[%s][inherit]', $key));
        
        $this->add($checkboxField);
        $this->add($field);

        $this->targetField = $field;
        $this->inheritField = $checkboxField;
    }