silverstripe-userforms/code/model/EditableCustomRule.php

<?php

/**
 * A custom rule for showing / hiding an EditableFormField
 * based the value of another EditableFormField.
 *
 * @method EditableFormField Parent()
 * @package userforms
 */
class EditableCustomRule extends DataObject {

	private static $condition_options = array(
		"IsBlank" => "Is blank",
		"IsNotBlank" => "Is not blank",
		"HasValue" => "Equals",
		"ValueNot" => "Doesn't equal",
		"ValueLessThan" => "Less than",
		"ValueLessThanEqual" => "Less than or equal",
		"ValueGreaterThan" => "Greater than",
		"ValueGreaterThanEqual" => "Greater than or equal"
	);

	private static $db = array(
		'Display' => 'Enum("Show,Hide")',
		'ConditionOption' => 'Enum("IsBlank,IsNotBlank,HasValue,ValueNot,ValueLessThan,ValueLessThanEqual,ValueGreaterThan,ValueGreaterThanEqual")',
		'FieldValue' => 'Varchar'
	);

	private static $has_one = array(
		'Parent' => 'EditableFormField',
		'ConditionField' => 'EditableFormField'
	);

	/**
	 * Built in extensions required
	 *
	 * @config
	 * @var array
	 */
	private static $extensions = array(
		"Versioned('Stage', 'Live')"
	);

	/**
	 * Publish this custom rule to the live site
	 *
	 * Wrapper for the {@link Versioned} publish function
	 */
	public function doPublish($fromStage, $toStage, $createNewVersion = false) {
		$this->publish($fromStage, $toStage, $createNewVersion);
	}

	/**
	 * Delete this custom rule from a given stage
	 *
	 * Wrapper for the {@link Versioned} deleteFromStage function
	 */
	public function doDeleteFromStage($stage) {
		$this->deleteFromStage($stage);
	}


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

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

    /**
     * @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);
    }
}