/// <summary>
/// Used to receive notifications when the value attribute is read or written.
/// </summary>
public ServiceResult OnWriteTagValue(
ISystemContext context,
NodeState node,
ref object value)
{
UnderlyingSystem system = context.SystemHandle as UnderlyingSystem;
if (system == null)
{
return(StatusCodes.BadCommunicationError);
}
UnderlyingSystemBlock block = system.FindBlock(m_blockId);
if (block == null)
{
return(StatusCodes.BadNodeIdUnknown);
}
uint error = block.WriteTagValue(node.SymbolicName, value);
if (error != 0)
{
// the simulator uses UA status codes so there is no need for a mapping table.
return(error);
}
return(ServiceResult.Good);
}
/// <summary>
/// Starts the monitoring the block.
/// </summary>
/// <param name="context">The context.</param>
public void StartMonitoring(ServerSystemContext context)
{
if (m_monitoringCount == 0)
{
UnderlyingSystem system = context.SystemHandle as UnderlyingSystem;
if (system != null)
{
UnderlyingSystemBlock block = system.FindBlock(m_blockId);
if (block != null)
{
block.StartMonitoring(OnTagsChanged);
}
}
}
m_monitoringCount++;
}
/// <summary>
/// Stop the monitoring the block.
/// </summary>
/// <param name="context">The context.</param>
public bool StopMonitoring(ServerSystemContext context)
{
m_monitoringCount--;
if (m_monitoringCount == 0)
{
UnderlyingSystem system = context.SystemHandle as UnderlyingSystem;
if (system != null)
{
UnderlyingSystemBlock block = system.FindBlock(m_blockId);
if (block != null)
{
block.StopMonitoring();
}
}
}
return(m_monitoringCount != 0);
}
/// <summary>
/// Returns the next child.
/// </summary>
private IReference NextChild()
{
UnderlyingSystem system = (UnderlyingSystem)this.SystemContext.SystemHandle;
NodeId targetId = null;
// check if a specific browse name is requested.
if (!QualifiedName.IsNull(base.BrowseName))
{
// check if match found previously.
if (m_position == Int32.MaxValue)
{
return(null);
}
// browse name must be qualified by the correct namespace.
if (m_source.BrowseName.NamespaceIndex != base.BrowseName.NamespaceIndex)
{
return(null);
}
// look for matching segment.
if (m_stage == Stage.Segments && m_segments != null)
{
for (int ii = 0; ii < m_segments.Count; ii++)
{
if (base.BrowseName.Name == m_segments[ii].Name)
{
targetId = ModelUtils.ConstructIdForSegment(m_segments[ii].Id, m_source.NodeId.NamespaceIndex);
break;
}
}
}
// look for matching block.
if (m_stage == Stage.Blocks && m_blocks != null)
{
for (int ii = 0; ii < m_blocks.Count; ii++)
{
UnderlyingSystemBlock block = system.FindBlock(m_blocks[ii]);
if (block != null && base.BrowseName.Name == block.Name)
{
targetId = ModelUtils.ConstructIdForBlock(m_blocks[ii], m_source.NodeId.NamespaceIndex);
break;
}
}
}
m_position = Int32.MaxValue;
}
// return the child at the next position.
else
{
// look for next segment.
if (m_stage == Stage.Segments && m_segments != null)
{
if (m_position >= m_segments.Count)
{
return(null);
}
targetId = ModelUtils.ConstructIdForSegment(m_segments[m_position++].Id, m_source.NodeId.NamespaceIndex);
}
// look for next block.
else if (m_stage == Stage.Blocks && m_blocks != null)
{
if (m_position >= m_blocks.Count)
{
return(null);
}
targetId = ModelUtils.ConstructIdForBlock(m_blocks[m_position++], m_source.NodeId.NamespaceIndex);
}
}
// create reference.
if (targetId != null)
{
return(new NodeStateReference(ReferenceTypeIds.Organizes, false, targetId));
}
return(null);
}