/// <summary>
/// Initializes the next stage of browsing.
/// </summary>
private void NextStage()
{
ComHdaClientManager system = (ComHdaClientManager)this.SystemContext.SystemHandle;
ComHdaClient client = (ComHdaClient)system.SelectClient((ServerSystemContext)SystemContext, false);
// determine which stage is next based on the reference types requested.
for (Stage next = m_stage + 1; next <= Stage.Done; next++)
{
if (next == Stage.Browse)
{
if (IsRequired(ReferenceTypeIds.Organizes, false))
{
m_stage = next;
break;
}
}
else if (next == Stage.Children)
{
if (IsRequired(ReferenceTypeIds.HasProperty, false) || IsRequired(ReferenceTypeIds.HasHistoricalConfiguration, false))
{
m_stage = next;
break;
}
}
else if (next == Stage.Parents)
{
if (IsRequired(ReferenceTypeIds.Organizes, true) || IsRequired(ReferenceTypeIds.HasHistoricalConfiguration, true))
{
m_stage = next;
break;
}
}
else if (next == Stage.Done)
{
m_stage = next;
break;
}
}
// start enumerating areas.
if (m_stage == Stage.Browse)
{
m_browser = null;
if (m_sourceTypeDefinitionId == Opc.Ua.ObjectTypeIds.FolderType)
{
m_browser = new ComHdaBrowserClient(client, m_itemId);
}
return;
}
// start enumerating attributes.
if (m_stage == Stage.Children)
{
m_position = 0;
m_children = null;
if (m_sourceTypeDefinitionId == Opc.Ua.ObjectTypeIds.FolderType)
{
return;
}
List <BaseInstanceState> children = new List <BaseInstanceState>();
// check if browsing aggregate functions.
if (m_sourceBrowseName == Opc.Ua.BrowseNames.AggregateFunctions)
{
if (IsRequired(ReferenceTypeIds.HasComponent, false))
{
BaseObjectState[] aggregates = client.GetSupportedAggregates(m_namespaceIndex);
if (aggregates != null)
{
children.AddRange(aggregates);
}
m_children = children.ToArray();
}
return;
}
// must be browsing children of an item.
HdaItem[] items = client.GetItems(m_itemId);
if (items[0].Error < 0)
{
return;
}
try
{
HdaAttributeValue[] attributes = client.ReadAvailableAttributes(items[0]);
if (m_sourceTypeDefinitionId == Opc.Ua.VariableTypeIds.DataItemType)
{
FindChildrenForHdaItem(client, children, attributes);
}
if (m_sourceTypeDefinitionId == Opc.Ua.ObjectTypeIds.HistoricalDataConfigurationType)
{
FindChildrenForHdaItemConfiguration(client, children, attributes);
}
}
finally
{
client.ReleaseItemHandles(items);
}
m_children = children.ToArray();
return;
}
// start enumerating parents.
if (m_stage == Stage.Parents)
{
return;
}
// all done.
}