Opc.Ua.Server.CustomNodeManager2.Read C# (CSharp) Method

        public virtual void Read(
            OperationContext     context, 
            double               maxAge, 
            IList<ReadValueId>   nodesToRead, 
            IList<DataValue>     values, 
            IList<ServiceResult> errors)
        {
            ServerSystemContext systemContext = m_systemContext.Copy(context);
            IDictionary<NodeId,NodeState> operationCache = new NodeIdDictionary<NodeState>();
            List<NodeHandle> nodesToValidate = new List<NodeHandle>();

            lock (Lock)
            {
                for (int ii = 0; ii < nodesToRead.Count; ii++)
                {                    
                    ReadValueId nodeToRead = nodesToRead[ii];

                    // skip items that have already been processed.
                    if (nodeToRead.Processed)
                    {
                        continue;
                    }
                    
                    // check for valid handle.
                    NodeHandle handle = GetManagerHandle(systemContext, nodeToRead.NodeId, operationCache);

                    if (handle == null)
                    {
                        continue;
                    }

                    // owned by this node manager.
                    nodeToRead.Processed = true;
                    
                    // create an initial value.
                    DataValue value = values[ii] = new DataValue();
                    
                    value.Value           = null;
                    value.ServerTimestamp = DateTime.UtcNow;
                    value.SourceTimestamp = DateTime.MinValue;
                    value.StatusCode      = StatusCodes.Good;

                    // check if the node is a area in memory.
                    if (handle.Node == null)
                    {
                        errors[ii] = StatusCodes.BadNodeIdUnknown;
                        
                        // must validate node in a seperate operation
                        handle.Index = ii;
                        nodesToValidate.Add(handle);
                        
                        continue;
                    }

                    // read the attribute value.
                    errors[ii] = handle.Node.ReadAttribute(
                        systemContext,
                        nodeToRead.AttributeId,
                        nodeToRead.ParsedIndexRange,
                        nodeToRead.DataEncoding,
                        value);
                }

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

            // validates the nodes (reads values from the underlying data source if required).
            Read(
                systemContext,
                nodesToRead,
                values,
                errors,
                nodesToValidate,
                operationCache);
        }