/// <summary>
/// Creates and indexes an area defined for the server.
/// </summary>
private AreaState CreateAndIndexAreas(AreaState parent, AreaConfiguration configuration)
{
// create a unique path to the area.
string areaPath = Utils.Format("{0}/{1}", (parent != null) ? parent.SymbolicName : String.Empty, configuration.Name);
NodeId areaId = ModelUtils.ConstructIdForArea(areaPath, NamespaceIndex);
// create the object that will be used to access the area and any variables contained within it.
AreaState area = new AreaState(SystemContext, parent, areaId, configuration);
m_areas[areaPath] = area;
if (parent != null)
{
parent.AddChild(area);
}
// create an index any sub-areas defined for the area.
if (configuration.SubAreas != null)
{
for (int ii = 0; ii < configuration.SubAreas.Count; ii++)
{
CreateAndIndexAreas(area, configuration.SubAreas[ii]);
}
}
// add references to sources.
if (configuration.SourcePaths != null)
{
for (int ii = 0; ii < configuration.SourcePaths.Count; ii++)
{
string sourcePath = configuration.SourcePaths[ii];
// check if the source already exists because it is referenced by another area.
SourceState source = null;
if (!m_sources.TryGetValue(sourcePath, out source))
{
NodeId sourceId = ModelUtils.ConstructIdForSource(sourcePath, NamespaceIndex);
m_sources[sourcePath] = source = new SourceState(this, sourceId, sourcePath);
}
// HasEventSource and HasNotifier control the propagation of event notifications so
// they are not like other references. These calls set up a link between the source
// and area that will cause events produced by the source to be automatically
// propagated to the area.
source.AddNotifier(SystemContext, ReferenceTypeIds.HasEventSource, true, area);
area.AddNotifier(SystemContext, ReferenceTypeIds.HasEventSource, false, source);
}
}
return(area);
}
/// <summary>
/// Verifies that the specified node exists.
/// </summary>
protected override NodeState ValidateNode(
ServerSystemContext context,
NodeHandle handle,
IDictionary <NodeId, NodeState> cache)
{
// not valid if no root.
if (handle == null)
{
return(null);
}
// check if previously validated.
if (handle.Validated)
{
return(handle.Node);
}
NodeState target = null;
// check if already in the cache.
if (cache != null)
{
if (cache.TryGetValue(handle.NodeId, out target))
{
// nulls mean a NodeId which was previously found to be invalid has been referenced again.
if (target == null)
{
return(null);
}
handle.Node = target;
handle.Validated = true;
return(handle.Node);
}
target = null;
}
try
{
// check if the node id has been parsed.
if (handle.ParsedNodeId == null)
{
return(null);
}
NodeState root = null;
// validate area.
if (handle.ParsedNodeId.RootType == ModelUtils.Area)
{
AreaState area = null;
if (!m_areas.TryGetValue(handle.ParsedNodeId.RootId, out area))
{
return(null);
}
root = area;
}
// validate soucre.
else if (handle.ParsedNodeId.RootType == ModelUtils.Source)
{
SourceState source = null;
if (!m_sources.TryGetValue(handle.ParsedNodeId.RootId, out source))
{
return(null);
}
root = source;
}
// unknown root type.
else
{
return(null);
}
// all done if no components to validate.
if (String.IsNullOrEmpty(handle.ParsedNodeId.ComponentPath))
{
handle.Validated = true;
handle.Node = target = root;
return(handle.Node);
}
// validate component.
NodeState component = root.FindChildBySymbolicName(context, handle.ParsedNodeId.ComponentPath);
// component does not exist.
if (component == null)
{
return(null);
}
// found a valid component.
handle.Validated = true;
handle.Node = target = component;
return(handle.Node);
}
finally
{
// store the node in the cache to optimize subsequent lookups.
if (cache != null)
{
cache.Add(handle.NodeId, target);
}
}
}