/// <summary>
/// Creates the appropriate NodeState object from a NodeId.
/// </summary>
public static NodeState CreateHandleFromNodeId(
ISystemContext context,
NodeId nodeId,
IDictionary <NodeId, NodeState> cache)
{
// get the system to use.
FileSystemMonitor system = context.SystemHandle as FileSystemMonitor;
if (system == null)
{
return(null);
}
// check for valid node id.
if (nodeId == null || nodeId.NamespaceIndex != system.m_namespaceIndex || nodeId.IdType != IdType.String)
{
return(null);
}
// lookup in cache.
NodeState state = null;
if (cache != null)
{
if (cache.TryGetValue(nodeId, out state))
{
return(state);
}
}
string path = (string)nodeId.Identifier;
uint baseline = (uint)Convert.ToUInt32('0');
// parse the object type id.
uint objectTypeId = 0;
int start = 0;
for (int ii = 0; ii < path.Length; ii++)
{
if (path[ii] == ':')
{
start = ii + 1;
break;
}
if (!Char.IsDigit(path[ii]))
{
return(null);
}
objectTypeId *= 10;
objectTypeId += (uint)Convert.ToUInt32(path[ii]) - baseline;
}
string parentPath = path;
NodeId parentId = nodeId;
// check if referencing a child of the object.
int end = -1;
if (start < path.Length)
{
end = path.IndexOf(':', start);
if (end >= start)
{
parentPath = path.Substring(0, end);
parentId = new NodeId(parentPath, system.NamespaceIndex);
}
}
// return cached value if available.
if (cache != null)
{
if (!cache.TryGetValue(parentId, out state))
{
state = null;
}
}
// create the object instance.
if (state == null)
{
switch (objectTypeId)
{
case ObjectTypes.AreaType:
{
string directoryPath = system.ExtractPathFromNodeId(nodeId);
state = new AreaState(context, new DirectoryInfo(directoryPath));
break;
}
case ObjectTypes.ControllerType:
{
string filePath = system.ExtractPathFromNodeId(nodeId);
filePath += ".csv";
state = new ControllerState(context, new FileInfo(filePath));
break;
}
default:
{
return(null);
}
}
// update cache if provided.
if (cache != null)
{
cache[parentId] = state;
}
}
// nothing more to do if referencing the root.
if (end < 0)
{
return(state);
}
// create the child identified by the name in the node id.
string childPath = path.Substring(end + 1);
// extract path of children.
List <string> childNames = new List <string>();
int index = childPath.IndexOf(':');
while (index > 0)
{
childNames.Add(childPath.Substring(0, index));
childPath = childPath.Substring(index + 1);
index = childPath.IndexOf(':');
}
childNames.Add(childPath);
NodeState parent = state;
BaseInstanceState child = null;
for (int ii = 0; ii < childNames.Count; ii++)
{
child = parent.CreateChild(
context,
new QualifiedName(childNames[ii], 0));
if (child == null)
{
return(null);
}
parent = child;
if (ii == childNames.Count - 1)
{
child.NodeId = nodeId;
if (state.ValidationRequired)
{
child.OnValidate = system.ValidateChild;
}
if (cache != null)
{
cache[nodeId] = child;
}
}
}
return(child);
}
