silverstripe-versionfeed/code/VersionFeedSiteConfig.php

<?php

/**
 * Allows global configuration of all changes
 */
class VersionFeedSiteConfig extends DataExtension {
	
	private static $db = array(
		'AllChangesEnabled' => 'Boolean(true)'
	);

	private static $defaults = array(
		'AllChangesEnabled' => true
	);

	public function updateFieldLabels(&$labels) {
		$labels['AllChangesEnabled'] = _t('VersionFeedSiteConfig.ALLCHANGESLABEL', 'Make global changes feed public');
	}
	
	public function updateCMSFields(\FieldList $fields) {
		if(!Config::inst()->get('VersionFeed', 'allchanges_enabled')) return;

		$fields->addFieldToTab('Root.Access',
			FieldGroup::create(new CheckboxField('AllChangesEnabled', $this->owner->fieldLabel('AllChangesEnabled')))
				->setTitle(_t('VersionFeedSiteConfig.ALLCHANGES', 'All page changes'))
				->setDescription(_t(
					'VersionFeed.Warning',
					"Publicising the history will also disclose the changes that have at the time been protected " .
					"from the public view."
				))
		);
	}
}