Products Google for Education Blockly Reference Blockly Framework Reference FieldListener public protocol FieldListener: class Protocol for events that occur on a Field instance. didUpdateField(_:) Event that is fired when one of a field’s properties has changed. Declaration Swift func didUpdateField(_ field: Field) Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated December 1, 2017.