getPreviewExtendedData method

ProgressListener getPreviewExtendedData(void onComplete(GemError error, SearchableParameterList? parameters))

Asynchronously retrieve the preview extended data for this item.

The operation is asynchronous and delivers results via the provided callback.

Parameters

• onComplete: Callback invoked with a GemError and a SearchableParameterList when available.

Parameters

• onComplete: Function called when the operation is completed. The function is called with:
  • GemError.success for error and non-null parameters on success.
  • GemError.invalidInput for error and null parameters if no listener was provided.
  • GemError.couldNotStart for error and null parameters if the request couldn't be started.
  • GemError.notSupported for error and null parameters if called even though hasPreviewExtendedData returned false.
  • GemError.general for error and null parameters in any other error case.
  • Other error codes for error and null parameters if an error occurred.

Returns

• A ProgressListener that can be used to monitor or cancel the operation.

See also:

• hasPreviewExtendedData - Property to check if extended data is available for this item.
• cancelGetPreviewExtendedData - Method to cancel a running preview extended data request.

Implementation

ProgressListener getPreviewExtendedData(
  final void Function(GemError error, SearchableParameterList? parameters)
  onComplete,
) {
  final EventDrivenProgressListener progListener =
      EventDrivenProgressListener();
  GemKitPlatform.instance.registerEventHandler(progListener.id, progListener);
  final SearchableParameterList params = SearchableParameterList.create(0);

  progListener.registerOnCompleteWithData((
    final int err,
    final String hint,
    final Map<dynamic, dynamic> json,
  ) {
    GemKitPlatform.instance.unregisterEventHandler(progListener.id);
    if (err != 0) {
      onComplete(GemErrorExtension.fromCode(err), null);
    } else {
      onComplete(GemErrorExtension.fromCode(err), params);
    }
  });

  final OperationResult resultString = objectMethod(
    pointerId,
    'OverlayItem',
    'getPreviewExtendedData',
    args: <String, dynamic>{
      'list': params.pointerId,
      'listener': progListener.id,
    },
  );

  final int id = resultString['result'];

  if (id != 0) {
    onComplete(GemErrorExtension.fromCode(id), null);
  }

  return progListener;
}