<?php
namespace wcf\system\form\builder\field;

/**
 * Implementation of a radio buttons form field for selecting a single value.
 * 
 * @author	Matthias Schmidt
 * @copyright	2001-2018 WoltLab GmbH
 * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 * @package	WoltLabSuite\Core\System\Form\Builder\Field
 * @since	3.2
 */
class RadioButtonFormField extends AbstractFormField implements ISelectionFormField {
	use TSelectionFormField;
	
	/**
	 * @inheritDoc
	 */
	protected $templateName = '__radioButtonFormField';
	
	/**
	 * @inheritDoc
	 */
	public function readValue(): IFormField {
		if ($this->getDocument()->hasRequestData($this->getPrefixedId())) {
			$value = $this->getDocument()->getRequestData($this->getPrefixedId());
			
			if (is_string($value)) {
				$this->__value = $value;
			}
		}
		
		return $this;
	}
	
	/**
	 * @inheritDoc
	 */
	public function supportsNestedOptions(): bool {
		return false;
	}
}

<?php
namespace wcf\system\form\builder\field;

/**
 * Implementation of a radio buttons form field for selecting a single value.
 * 
 * @author	Matthias Schmidt
 * @copyright	2001-2018 WoltLab GmbH
 * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 * @package	WoltLabSuite\Core\System\Form\Builder\Field
 * @since	3.2
 */
class RadioButtonFormField extends AbstractFormField implements ISelectionFormField {
	use TSelectionFormField;
	
	/**
	 * @inheritDoc
	 */
	protected $templateName = '__radioButtonFormField';
	
	/**
	 * @inheritDoc
	 */
	protected static function supportsNestedOptions(): bool {
		return false;
	}
}

--- 
+++ 
@@ -21,7 +21,22 @@
 	/**
 	 * @inheritDoc
 	 */
-	protected static function supportsNestedOptions(): bool {
+	public function readValue(): IFormField {
+		if ($this->getDocument()->hasRequestData($this->getPrefixedId())) {
+			$value = $this->getDocument()->getRequestData($this->getPrefixedId());
+			
+			if (is_string($value)) {
+				$this->__value = $value;
+			}
+		}
+		
+		return $this;
+	}
+	
+	/**
+	 * @inheritDoc
+	 */
+	public function supportsNestedOptions(): bool {
 		return false;
 	}
 }
Add missing method in `RadioButtonFormField`

See 89f146f98c612e7924de77816920cf9553ef626a
See #2509
