getPreviewData method

ProgressListener? getPreviewData(
  1. void onResult(
    1. GemError error,
    2. SearchableParameterList? parameters
    )
)

Get the traffic preview data as a list of parameters

Parameters

  • IN onComplete Will be invoked when the operation is completed, providing the results and an error code.
    • Will call with error code GemError.success and non-null results on success
    • Will call with error code GemError.notSupported and non-null results if the operation is not supported for this object
    • Will call with error code GemError.noConnection and non-null results if internet connection is not available
    • Will call with error code GemError.notFound and non-null results if no preview data is available for this event
    • Will call with error code GemError.general and non-null results if the request failed
    • Will call with other error codes and null results on failure

Returns

  • The ProgressListener associated to the request if it could be started, null otherwise

Throws

  • An exception if it fails

Implementation

ProgressListener? getPreviewData(
  void Function(GemError error, SearchableParameterList? parameters) onResult,
) {
  final EventDrivenProgressListener listener = EventDrivenProgressListener();
  GemKitPlatform.instance.registerEventHandler(listener.id, listener);
  final SearchableParameterList parameterList = SearchableParameterList();

  listener.registerOnCompleteWithDataCallback((int code, _, __) {
    final GemError error = GemErrorExtension.fromCode(code);
    GemKitPlatform.instance.unregisterEventHandler(listener.id);
    if (error != GemError.success) {
      onResult(error, null);
    } else {
      onResult(error, parameterList);
    }
  });

  final OperationResult resultString = objectMethod(
    _pointerId,
    'TrafficEvent',
    'getPreviewData',
    args: <String, dynamic>{
      'first': parameterList.pointerId,
      'second': listener.id,
    },
  );

  if (resultString['result'] != 0) {
    GemKitPlatform.instance.unregisterEventHandler(listener.id);
    onResult(GemErrorExtension.fromCode(resultString['result']), null);
    return null;
  }

  return listener;
}