/// <summary>
/// Initializes a new instance of the <see cref="ComAeSubscriptionClient"/> class.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="cache">The cache for known types.</param>
/// <param name="namespaceIndex">The namespace index for the event types.</param>
/// <param name="manager">The manager.</param>
/// <param name="monitoredItem">The monitored item.</param>
public ComAeSubscriptionClient(
ServerSystemContext context,
ComAeClientConfiguration configuration,
AeTypeCache cache,
ushort namespaceIndex,
ComAeClientManager manager,
MonitoredItem monitoredItem)
{
m_defaultContext = context;
m_separators = configuration.SeperatorChars;
m_cache = cache;
m_namespaceIndex = namespaceIndex;
m_manager = manager;
m_refreshComplete = new ManualResetEvent(false);
m_monitoredItems = new List <MonitoredItem>();
m_monitoredItems.Add(monitoredItem);
m_qualifiedName = null;
m_isSource = false;
NodeHandle handle = monitoredItem.ManagerHandle as NodeHandle;
AeAreaState area = handle.Node as AeAreaState;
if (area != null)
{
m_qualifiedName = area.QualifiedName;
m_isSource = false;
}
else
{
AeSourceState source = handle.Node as AeSourceState;
if (source != null)
{
m_qualifiedName = source.QualifiedName;
m_isSource = true;
}
}
}
/// <summary>
/// Returns the next AE area or source.
/// </summary>
/// <returns>A DA element. Null if nothing left to browse.</returns>
public BaseObjectState Next(ISystemContext context, ushort namespaceIndex)
{
// check if already completed.
if (m_completed)
{
return(null);
}
// create the browser.
if (base.Unknown == null)
{
base.Unknown = m_client.CreateAreaBrowser();
if (base.Unknown == null)
{
return(null);
}
if (!ChangeBrowsePosition(OPCAEBROWSEDIRECTION.OPCAE_BROWSE_TO, m_qualifiedName))
{
return(null);
}
}
// create the enumerator if not already created.
if (m_enumerator == null)
{
m_enumerator = CreateEnumerator(false);
m_sources = false;
// a null indicates an error.
if (m_enumerator == null)
{
m_completed = true;
return(null);
}
}
// need a loop in case errors occur fetching element metadata.
BaseObjectState node = null;
do
{
// fetch the next name.
string name = m_enumerator.Next();
// a null indicates the end of list.
if (name == null)
{
if (!m_sources)
{
m_enumerator.Dispose();
m_enumerator = CreateEnumerator(true);
m_sources = true;
continue;
}
m_completed = true;
return(null);
}
// create the node.
if (m_sources)
{
string qualifiedName = GetQualifiedSourceName(name);
if (String.IsNullOrEmpty(qualifiedName))
{
continue;
}
node = new AeSourceState(context, m_qualifiedName, qualifiedName, name, namespaceIndex);
}
else
{
string qualifiedName = GetQualifiedAreaName(name);
if (String.IsNullOrEmpty(qualifiedName))
{
continue;
}
node = new AeAreaState(context, qualifiedName, name, namespaceIndex);
}
break;
}while (node == null);
// return node.
return(node);
}
/// <summary>
/// Returns the next AE area or source.
/// </summary>
/// <returns>A DA element. Null if nothing left to browse.</returns>
public BaseObjectState Next(ISystemContext context, ushort namespaceIndex)
{
// check if already completed.
if (m_completed)
{
return null;
}
// create the browser.
if (base.Unknown == null)
{
base.Unknown = m_client.CreateAreaBrowser();
if (base.Unknown == null)
{
return null;
}
if (!ChangeBrowsePosition(OPCAEBROWSEDIRECTION.OPCAE_BROWSE_TO, m_qualifiedName))
{
return null;
}
}
// create the enumerator if not already created.
if (m_enumerator == null)
{
m_enumerator = CreateEnumerator(false);
m_sources = false;
// a null indicates an error.
if (m_enumerator == null)
{
m_completed = true;
return null;
}
}
// need a loop in case errors occur fetching element metadata.
BaseObjectState node = null;
do
{
// fetch the next name.
string name = m_enumerator.Next();
// a null indicates the end of list.
if (name == null)
{
if (!m_sources)
{
m_enumerator.Dispose();
m_enumerator = CreateEnumerator(true);
m_sources = true;
continue;
}
m_completed = true;
return null;
}
// create the node.
if (m_sources)
{
string qualifiedName = GetQualifiedSourceName(name);
if (String.IsNullOrEmpty(qualifiedName))
{
continue;
}
node = new AeSourceState(context, m_qualifiedName, qualifiedName, name, namespaceIndex);
}
else
{
string qualifiedName = GetQualifiedAreaName(name);
if (String.IsNullOrEmpty(qualifiedName))
{
continue;
}
node = new AeAreaState(context, qualifiedName, name, namespaceIndex);
}
break;
}
while (node == null);
// return node.
return node;
}