OPC Studio User's Guide and Reference
Examples - OPC UA GDS and CM - Unregister all clients

.NET

// Shows how to unregister all clients from a GDS.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using System.Collections.Generic;
using System.Linq;
using OpcLabs.BaseLib.Collections.Generic.Extensions;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.Extensions;
using OpcLabs.EasyOpc.UA.Gds;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.Gds._EasyUAGlobalDiscoveryClient
{
    class UnregisterApplication
    {
        public static void Main1()
        {
            // Define which GDS we will work with.
            UAEndpointDescriptor gdsEndpointDescriptor =
                ((UAEndpointDescriptor)"opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer")
                .WithUserNameIdentity("appadmin", "demo");

            // Instantiate the global discovery client object
            var globalDiscoveryClient = new EasyUAGlobalDiscoveryClient();

            // Find application IDs of all client applications registered in the GDS.
            var clientApplicationIds = new HashSet<UANodeId>();
            try
            {
                globalDiscoveryClient.QueryApplications(
                    gdsEndpointDescriptor: gdsEndpointDescriptor,
                    startingRecordId: 0,
                    maximumRecordsToReturn: 0,
                    applicationName: "",
                    applicationUriString: "",
                    applicationTypes: UAApplicationTypes.Client,
                    productUriString: "",
                    serverCapabilities: new string[0],
                    lastCounterResetTime: out _,
                    nextRecordId: out _,
                    applications: out UAApplicationDescription[] applicationDescriptionArray);

                foreach (UAApplicationDescription applicationDescription in applicationDescriptionArray)
                {
                    var applicationRecordArray = globalDiscoveryClient.FindApplications(
                        gdsEndpointDescriptor,
                        applicationDescription.ApplicationUriString);
                    clientApplicationIds.AddRange(applicationRecordArray.Select(description => description.ApplicationId));
                }
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Unregister all client applications found.
            foreach (UANodeId applicationId in clientApplicationIds)
            {
                Console.WriteLine();
                Console.WriteLine("Application ID: {0}", applicationId);

                try
                {
                    globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId);
                }
                catch (UAException uaException)
                {
                    Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                    continue;
                }
                Console.WriteLine("Unregistered.");
            }
        }
    }
}
' Shows how to unregister all clients from a GDS.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System.Linq
Imports OpcLabs.BaseLib.Collections.Generic.Extensions
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.Extensions
Imports OpcLabs.EasyOpc.UA.Gds
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Gds._EasyUAGlobalDiscoveryClient
    Friend Class UnregisterApplication
        Public Shared Sub Main1()

            ' Define which GDS we will work with.
            Dim gdsEndpointDescriptor As UAEndpointDescriptor =
                New UAEndpointDescriptor("opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer") _
                .WithUserNameIdentity("appadmin", "demo")

            ' Instantiate the global discovery client object
            Dim globalDiscoveryClient = New EasyUAGlobalDiscoveryClient()

            ' Find application IDs of all client applications registered in the GDS.
            Dim clientApplicationIds = New HashSet(Of UANodeId)
            Try
                Dim lastCounterResetTime As DateTime
                Dim nextRecordId As Long
                Dim applicationDescriptionArray() As UAApplicationDescription = Nothing
                globalDiscoveryClient.QueryApplications(
                    gdsEndpointDescriptor:=gdsEndpointDescriptor,
                    startingRecordId:=0,
                    maximumRecordsToReturn:=0,
                    applicationName:="",
                    applicationUriString:="",
                    applicationTypes:=UAApplicationTypes.Client,
                    productUriString:="",
                    serverCapabilities:=New String() {},
                    lastCounterResetTime:=lastCounterResetTime,
                    nextRecordId:=nextRecordId,
                    applications:=applicationDescriptionArray)

                For Each applicationDescription As UAApplicationDescription In applicationDescriptionArray
                    Dim applicationRecordArray = globalDiscoveryClient.FindApplications(
                        gdsEndpointDescriptor,
                        applicationDescription.ApplicationUriString)
                    clientApplicationIds.AddRange(applicationRecordArray.Select(Function(description) description.ApplicationId))
                Next applicationDescription
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Unregister all client applications found.
            For Each applicationId As UANodeId In clientApplicationIds
                Console.WriteLine()
                Console.WriteLine("Application ID: {0}", applicationId)

                Try
                    globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId)
                Catch uaException As UAException
                    Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                    Continue For
                End Try
                Console.WriteLine("Unregistered.")
            Next applicationId
        End Sub
    End Class
End Namespace

COM

// Shows how to unregister all clients from a GDS.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

class procedure UnregisterApplication.Main;
var
  ApplicationDescription: _UAApplicationDescription;
  ApplicationDescriptionArray: OleVariant;
  ApplicationId: _UANodeId;
  ApplicationName: WideString;
  ApplicationRecord: _UAApplicationRecordDataType;
  ApplicationRecordArray: OleVariant;
  ApplicationUriString: WideString;
  ClientApplicationIds: TList<_UANodeID>;
  GlobalDiscoveryClient: OpcLabs_EasyOpcUA_TLB._EasyUAGlobalDiscoveryClient;
  GdsEndpointDescriptor: _UAEndpointDescriptor;
  I, J: integer;
  LastCounterResetTime: TDateTime;
  MaximumRecordsToReturn: Integer;
  NextRecordId: Integer;
  ProductUriString: WideString;
  ServerCapabilities: array of string;
  StartingRecordId: Integer;
begin
  // Define which GDS we will work with.
  GdsEndpointDescriptor := CoUAEndpointDescriptor.Create;
  GdsEndpointDescriptor.UrlString := 'opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.UserName := 'appadmin';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.Password := 'demo';

  // Instantiate the global discovery client object
  GlobalDiscoveryClient := CoEasyUAGlobalDiscoveryClient.Create;

  // Find application IDs of all client applications registered in the GDS.
  ClientApplicationIds := TList<_UANodeID>.Create();
  StartingRecordId := 0;
  MaximumRecordsToReturn := 0;
  ApplicationName := '';
  ApplicationUriString := '';
  ProductUriString := '';
  try
    GlobalDiscoveryClient.QueryApplications(
      GdsEndpointDescriptor,
      StartingRecordId,
      MaximumRecordsToReturn,
      ApplicationName,
      ApplicationUriString,
      UAApplicationTypes_Client,
      ProductUriString,
      ServerCapabilities,
      LastCounterResetTime,
      NextRecordId,
      ApplicationDescriptionArray);

    for I := VarArrayLowBound(ApplicationDescriptionArray,1) to VarArrayHighBound(ApplicationDescriptionArray,1) do
    begin
      ApplicationDescription := IUnknown(ApplicationDescriptionArray[I]) as _UAApplicationDescription;
      TVarData(ApplicationRecordArray).VType := varArray or varVariant;
      TVarData(ApplicationRecordArray).VArray := PVarArray(GlobalDiscoveryClient.FindApplications(
        GdsEndpointDescriptor, ApplicationDescription.ApplicationUriString));
      for J := VarArrayLowBound(ApplicationRecordArray,1) to VarArrayHighBound(ApplicationRecordArray,1) do
      begin
        ApplicationRecord := IUnknown(ApplicationRecordArray[J]) as _UAApplicationRecordDataType;
        ClientApplicationIds.Add(ApplicationRecord.ApplicationId);
      end;
    end;
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
    end;
  end;

  // Unregister all client applications found.
  for ApplicationId in ClientApplicationIds do
  begin
    WriteLn;
    WriteLn('Application ID: ', ApplicationId.ToString);
    try
      GlobalDiscoveryClient.UnregisterApplication(
        GdsEndpointDescriptor, ApplicationId);
    except
      on E: EOleException do
      begin
        WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
        Continue;
      end;
    end;
    WriteLn('Unregistered.');
  end;
  FreeAndNil(ClientApplicationIds);
end;

Python

# Shows how to unregister all clients from a GDS.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Discovery import *
from OpcLabs.EasyOpc.UA.Extensions import *
from OpcLabs.EasyOpc.UA.Gds import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Define which GDS we will work with.
gdsEndpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer')
gdsEndpointDescriptor = UAEndpointDescriptorExtension.WithUserNameIdentity(gdsEndpointDescriptor,
                                                                           'appadmin', 'demo')

# Instantiate the global discovery client object.
globalDiscoveryClient = EasyUAGlobalDiscoveryClient()

# Find application IDs of all client applications registered in the GDS.
clientApplicationIds = set()
try:
    _, _, _, applicationDescriptionArray = globalDiscoveryClient.QueryApplications(
        gdsEndpointDescriptor,
        0,  # startingRecordId
        0,  # maximumRecordsToReturn
        '', # applicationName
        '', # applicationUriString
        UAApplicationTypes.Client, # applicationTypes
        '', # productUriString
        Array.Empty[String](),  # serverCapabilities
        DateTime(), # out lastCounterResetTime
        0,  # out nextRecordId
        Array.Empty[UAApplicationDescription]()) # out applications

    for applicationDescription in applicationDescriptionArray:
        applicationRecordArray = globalDiscoveryClient.FindApplications(
            gdsEndpointDescriptor,
            applicationDescription.ApplicationUriString)
        for applicationRecord in applicationRecordArray:
            clientApplicationIds.add(applicationRecord.ApplicationId)

except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Unregister all client applications found.
for applicationId in clientApplicationIds:
    print()
    print('Application ID: ', applicationId, sep='')

    try:
        globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId)
    except UAException as uaException:
        print('*** Failure: ' + uaException.GetBaseException().Message)
        continue
    print('Application unregistered.')

print()
print('Finished.')
See Also

Concepts

Fundamentals