debugDescribeChildren method Null safety

  1. @override
List<DiagnosticsNode> debugDescribeChildren()

Returns a list of DiagnosticsNode objects describing this node's children.

Children that are offstage should be added with style set to DiagnosticsTreeStyle.offstage to indicate that they are offstage.

The list must not contain any null entries. If there are explicit null children to report, consider new DiagnosticsNode.message or DiagnosticsProperty<Object> as possible DiagnosticsNode objects to provide.

Used by toStringDeep, toDiagnosticsNode and toStringShallow.

See also:


List<DiagnosticsNode> debugDescribeChildren() {
  if (collection != null && collection!.isNotEmpty) {
    return collection!.map<DiagnosticsNode>((T value) {
      if (value is Diagnosticable) {
        return value.toDiagnosticsNode();
      } else {
        return DiagnosticsProperty<T>('', value);
  return super.debugDescribeChildren();