Opc.Ua.Server.MonitoredItem.GetEventFields C# (CSharp) Method

        private EventFieldList GetEventFields(FilterContext context, EventFilter filter, IFilterTarget instance)
        {
            // fetch the event fields.
            EventFieldList fields = new EventFieldList();

            fields.ClientHandle = m_clientHandle;
            fields.Handle = instance;

            foreach (SimpleAttributeOperand clause in filter.SelectClauses)
            {
                // get the value of the attribute (apply localization).
                object value = instance.GetAttributeValue(
                    context, 
                    clause.TypeDefinitionId, 
                    clause.BrowsePath, 
                    clause.AttributeId, 
                    clause.ParsedIndexRange);

                // add the value to the list of event fields.
                if (value != null)
                {
                    // translate any localized text.
                    LocalizedText text = value as LocalizedText;

                    if (text != null)
                    {
                        value = m_server.ResourceManager.Translate(m_session.PreferredLocales, text);
                    }

                    // add value.
                    fields.EventFields.Add(new Variant(value));
                }

                // add a dummy entry for missing values.
                else
                {
                    fields.EventFields.Add(Variant.Null);
                }
            }

            return fields;
        }