silverstripe-userforms/code/model/editableformfields/EditableOption.php

<?php

/**
 * Base Class for EditableOption Fields such as the ones used in
 * dropdown fields and in radio check box groups
 *
 * @method EditableMultipleOptionField Parent()
 * @package userforms
 */
class EditableOption extends DataObject {

	private static $default_sort = "Sort";

	private static $db = array(
		"Name" => "Varchar(255)",
		"Title" => "Varchar(255)",
		"Default" => "Boolean",
		"Sort" => "Int"
	);

	private static $has_one = array(
		"Parent" => "EditableMultipleOptionField",
	);

	private static $extensions = array(
		"Versioned('Stage', 'Live')"
	);

	private static $summary_fields = array(
		'Title',
		'Default'
	);

	/**
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function canEdit($member = null) {
		return $this->Parent()->canEdit($member);
	}

	/**
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function canDelete($member = null) {
		return $this->canEdit($member);
	}

	public function getEscapedTitle() {
		return Convert::raw2att($this->Title);
	}

    /**
     * @param Member $member
     * @return bool
     */
	public function canView($member = null) {
		return $this->Parent()->canView($member);
	}

	/**
	 * Return whether a user can create an object of this type
	 *
     * @param Member $member
     * @param array $context Virtual parameter to allow context to be passed in to check
	 * @return bool
	 */
	public function canCreate($member = null) {
		// Check parent page
        $parent = $this->getCanCreateContext(func_get_args());
        if($parent) {
            return $parent->canEdit($member);
        }

        // Fall back to secure admin permissions
        return parent::canCreate($member);
	}

    /**
     * Helper method to check the parent for this object
     *
     * @param array $args List of arguments passed to canCreate
     * @return DataObject Some parent dataobject to inherit permissions from
     */
    protected function getCanCreateContext($args) {
        // Inspect second parameter to canCreate for a 'Parent' context
        if(isset($args[1]['Parent'])) {
            return $args[1]['Parent'];
        }
        // Hack in currently edited page if context is missing
        if(Controller::has_curr() && Controller::curr() instanceof CMSMain) {
            return Controller::curr()->currentPage();
        }

        // No page being edited
        return null;
    }

    /**
     * @param Member $member
     * @return bool
     */
    public function canPublish($member = null) {
        return $this->canEdit($member);
    }

    /**
     * @param Member $member
     * @return bool
     */
    public function canUnpublish($member = null) {
        return $this->canDelete($member);
    }

    /**
     *
     */
    protected function onBeforeWrite() {
        if (!$this->Sort) {
            $this->Sort = EditableOption::get()->max('Sort') + 1;
        }

        parent::onBeforeWrite();
    }
}