/// <summary>
 /// Creates a new instance of a FilterDeclarationField.
 /// </summary>
 public FilterDeclarationField(InstanceDeclaration instanceDeclaration)
 {
     Selected            = true;
     DisplayInList       = false;
     FilterEnabled       = false;
     FilterOperator      = FilterOperator.Equals;
     FilterValue         = Variant.Null;
     InstanceDeclaration = instanceDeclaration;
 }
        /// <summary>
        /// Collects the fields for the instance node.
        /// </summary>
        private static void CollectInstanceDeclarations(
            Session session,
            NodeId typeId,
            InstanceDeclaration parent,
            List <InstanceDeclaration> instances,
            IDictionary <string, InstanceDeclaration> map)
        {
            // find the children.
            BrowseDescription nodeToBrowse = new BrowseDescription();

            if (parent == null)
            {
                nodeToBrowse.NodeId = typeId;
            }
            else
            {
                nodeToBrowse.NodeId = parent.NodeId;
            }

            nodeToBrowse.BrowseDirection = BrowseDirection.Forward;
            nodeToBrowse.ReferenceTypeId = ReferenceTypeIds.HasChild;
            nodeToBrowse.IncludeSubtypes = true;
            nodeToBrowse.NodeClassMask   = (uint)(NodeClass.Object | NodeClass.Variable | NodeClass.Method);
            nodeToBrowse.ResultMask      = (uint)BrowseResultMask.All;

            // ignore any browsing errors.
            ReferenceDescriptionCollection references = ClientUtils.Browse(session, nodeToBrowse, false);

            if (references == null)
            {
                return;
            }

            // process the children.
            List <NodeId> nodeIds = new List <NodeId>();
            List <InstanceDeclaration> children = new List <InstanceDeclaration>();

            for (int ii = 0; ii < references.Count; ii++)
            {
                ReferenceDescription reference = references[ii];

                if (reference.NodeId.IsAbsolute)
                {
                    continue;
                }

                // create a new declaration.
                InstanceDeclaration child = new InstanceDeclaration();

                child.RootTypeId = typeId;
                child.NodeId     = (NodeId)reference.NodeId;
                child.BrowseName = reference.BrowseName;
                child.NodeClass  = reference.NodeClass;

                if (!LocalizedText.IsNullOrEmpty(reference.DisplayName))
                {
                    child.DisplayName = reference.DisplayName.Text;
                }
                else
                {
                    child.DisplayName = reference.BrowseName.Name;
                }

                if (parent != null)
                {
                    child.BrowsePath            = new QualifiedNameCollection(parent.BrowsePath);
                    child.BrowsePathDisplayText = Utils.Format("{0}/{1}", parent.BrowsePathDisplayText, reference.BrowseName);
                    child.DisplayPath           = Utils.Format("{0}/{1}", parent.DisplayPath, reference.DisplayName);
                }
                else
                {
                    child.BrowsePath            = new QualifiedNameCollection();
                    child.BrowsePathDisplayText = Utils.Format("{0}", reference.BrowseName);
                    child.DisplayPath           = Utils.Format("{0}", reference.DisplayName);
                }

                child.BrowsePath.Add(reference.BrowseName);

                // check if reading an overridden declaration.

                if (map.TryGetValue(child.BrowsePathDisplayText, out InstanceDeclaration overriden))
                {
                    child.OverriddenDeclaration = overriden;
                }

                map[child.BrowsePathDisplayText] = child;

                // add to list.
                children.Add(child);
                nodeIds.Add(child.NodeId);
            }

            // check if nothing more to do.
            if (children.Count == 0)
            {
                return;
            }

            // find the modelling rules.
            List <NodeId> modellingRules = FindTargetOfReference(session, nodeIds, Opc.Ua.ReferenceTypeIds.HasModellingRule, false);

            if (modellingRules != null)
            {
                for (int ii = 0; ii < nodeIds.Count; ii++)
                {
                    children[ii].ModellingRule = modellingRules[ii];

                    // if the modelling rule is null then the instance is not part of the type declaration.
                    if (NodeId.IsNull(modellingRules[ii]))
                    {
                        map.Remove(children[ii].BrowsePathDisplayText);
                    }
                }
            }

            // update the descriptions.
            UpdateInstanceDescriptions(session, children, false);

            // recusively collect instance declarations for the tree below.
            for (int ii = 0; ii < children.Count; ii++)
            {
                if (!NodeId.IsNull(children[ii].ModellingRule))
                {
                    instances.Add(children[ii]);
                    CollectInstanceDeclarations(session, typeId, children[ii], instances, map);
                }
            }
        }
        /// <summary>
        /// Finds the targets for the specified reference.
        /// </summary>
        private static void UpdateInstanceDescriptions(Session session, List <InstanceDeclaration> instances, bool throwOnError)
        {
            try
            {
                ReadValueIdCollection nodesToRead = new ReadValueIdCollection();

                for (int ii = 0; ii < instances.Count; ii++)
                {
                    ReadValueId nodeToRead = new ReadValueId();
                    nodeToRead.NodeId      = instances[ii].NodeId;
                    nodeToRead.AttributeId = Attributes.Description;
                    nodesToRead.Add(nodeToRead);

                    nodeToRead             = new ReadValueId();
                    nodeToRead.NodeId      = instances[ii].NodeId;
                    nodeToRead.AttributeId = Attributes.DataType;
                    nodesToRead.Add(nodeToRead);

                    nodeToRead             = new ReadValueId();
                    nodeToRead.NodeId      = instances[ii].NodeId;
                    nodeToRead.AttributeId = Attributes.ValueRank;
                    nodesToRead.Add(nodeToRead);
                }

                // start the browse operation.

                session.Read(
                    null,
                    0,
                    TimestampsToReturn.Neither,
                    nodesToRead,
                    out DataValueCollection results,
                    out DiagnosticInfoCollection diagnosticInfos);

                ClientBase.ValidateResponse(results, nodesToRead);
                ClientBase.ValidateDiagnosticInfos(diagnosticInfos, nodesToRead);

                // update the instances.
                for (int ii = 0; ii < nodesToRead.Count; ii += 3)
                {
                    InstanceDeclaration instance = instances[ii / 3];

                    instance.Description = results[ii].GetValue <LocalizedText>(LocalizedText.Null).Text;
                    instance.DataType    = results[ii + 1].GetValue <NodeId>(NodeId.Null);
                    instance.ValueRank   = results[ii + 2].GetValue <int>(ValueRanks.Any);

                    if (!NodeId.IsNull(instance.DataType))
                    {
                        instance.BuiltInType         = DataTypes.GetBuiltInType(instance.DataType, session.TypeTree);
                        instance.DataTypeDisplayText = session.NodeCache.GetDisplayText(instance.DataType);

                        if (instance.ValueRank >= 0)
                        {
                            instance.DataTypeDisplayText += "[]";
                        }
                    }
                }
            }
            catch (Exception exception)
            {
                if (throwOnError)
                {
                    throw new ServiceResultException(exception, StatusCodes.BadUnexpectedError);
                }
            }
        }