/// <summary>
/// Method to remove the node from the subscription and stop publishing telemetry to IoTHub. Executes synchronously.
/// </summary>
private ServiceResult OnUnpublishNodeCall(ISystemContext context, MethodState method, IList <object> inputArguments, IList <object> outputArguments)
{
string logPrefix = "OnUnpublishNodeCall:";
if (string.IsNullOrEmpty(inputArguments[0] as string) || string.IsNullOrEmpty(inputArguments[1] as string))
{
Logger.Error($"{logPrefix} Invalid arguments!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide all arguments!"));
}
HttpStatusCode statusCode = HttpStatusCode.InternalServerError;
NodeId nodeId = null;
ExpandedNodeId expandedNodeId = null;
Uri endpointUri = null;
bool isNodeIdFormat = true;
try
{
string id = inputArguments[0] as string;
if (id.Contains("nsu=", StringComparison.InvariantCulture))
{
expandedNodeId = ExpandedNodeId.Parse(id);
isNodeIdFormat = false;
}
else
{
nodeId = NodeId.Parse(id);
isNodeIdFormat = true;
}
endpointUri = new Uri(inputArguments[1] as string);
}
catch (UriFormatException)
{
Logger.Error($"{logPrefix} The endpointUrl is invalid '{inputArguments[1] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA endpoint URL as second argument!"));
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} The NodeId has an invalid format '{inputArguments[0] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA NodeId in NodeId or ExpandedNodeId format as first argument!"));
}
// find the session and stop monitoring the node.
try
{
NodeConfiguration.OpcSessionsListSemaphore.Wait();
if (ShutdownTokenSource.IsCancellationRequested)
{
return(ServiceResult.Create(StatusCodes.BadUnexpectedError, $"Publisher shutdown in progress."));
}
// find the session we need to monitor the node
OpcUaSessionManager opcSession = null;
try
{
opcSession = NodeConfiguration.OpcSessions.FirstOrDefault(s => s.EndpointUrl.Equals(endpointUri.OriginalString, StringComparison.OrdinalIgnoreCase));
}
catch
{
opcSession = null;
}
if (opcSession == null)
{
// do nothing if there is no session for this endpoint.
Logger.Error($"{logPrefix} Session for endpoint '{endpointUri.OriginalString}' not found.");
return(ServiceResult.Create(StatusCodes.BadSessionIdInvalid, "Session for endpoint of node to unpublished not found!"));
}
else
{
if (isNodeIdFormat)
{
// stop monitoring the node, execute syncronously
Logger.Information($"{logPrefix} Request to stop monitoring item with NodeId '{nodeId.ToString()}')");
statusCode = opcSession.RequestMonitorItemRemovalAsync(nodeId, null, ShutdownTokenSource.Token).Result;
}
else
{
// stop monitoring the node, execute syncronously
Logger.Information($"{logPrefix} Request to stop monitoring item with ExpandedNodeId '{expandedNodeId.ToString()}')");
statusCode = opcSession.RequestMonitorItemRemovalAsync(null, expandedNodeId, ShutdownTokenSource.Token).Result;
}
}
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} Exception while trying to configure publishing node '{nodeId.ToString()}'");
return(ServiceResult.Create(e, StatusCodes.BadUnexpectedError, $"Unexpected error unpublishing node: {e.Message}"));
}
finally
{
NodeConfiguration.OpcSessionsListSemaphore.Release();
}
return(statusCode == HttpStatusCode.OK || statusCode == HttpStatusCode.Accepted ? ServiceResult.Good : ServiceResult.Create(StatusCodes.Bad, "Can not stop monitoring node!"));
}
