/// <summary>
/// Finds the children that match the pattern (updates cache if required).
/// </summary>
private List <AeBrowseElement> Browse(Session session, AeBrowseElement start, string pattern, bool isArea)
{
// check cache.
List <AeBrowseElement> targets = (isArea)?start.Areas:start.Sources;
if (targets == null)
{
// fetch from server.
targets = Browse(session, start, isArea);
// update cache.
if (isArea)
{
start.Areas = targets;
}
else
{
start.Sources = targets;
}
}
// check if all matched.
if (String.IsNullOrEmpty(pattern) || pattern == "*")
{
return(targets);
}
// apply filter.
List <AeBrowseElement> hits = new List <AeBrowseElement>();
for (int ii = 0; ii < targets.Count; ii++)
{
if (ComUtils.Match(targets[ii].BrowseText, pattern, false))
{
hits.Add(targets[ii]);
}
}
return(hits);
}
/// <summary>
/// Browses for the children of the specified item.
/// </summary>
/// <param name="session">The session.</param>
/// <param name="itemId">The item id.</param>
/// <param name="continuationPoint">The continuation point.</param>
/// <param name="maxElementsReturned">The max elements returned.</param>
/// <param name="elementFilter">The element filter.</param>
/// <param name="nameFilter">The name filter.</param>
/// <param name="revisedContinuationPoint">The revised continuation point.</param>
/// <returns>The list of elements that meet the criteria.</returns>
public List <ComDaBrowseElement> BrowseForElements(
Session session,
string itemId,
string continuationPoint,
int maxElementsReturned,
int elementFilter,
string nameFilter,
out string revisedContinuationPoint)
{
TraceState("BrowseForElements", itemId, continuationPoint, maxElementsReturned, elementFilter, nameFilter);
revisedContinuationPoint = String.Empty;
// look up continuation point.
ContinuationPoint cp = null;
if (!String.IsNullOrEmpty(continuationPoint))
{
if (!m_continuationPoints.TryGetValue(continuationPoint, out cp))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDCONTINUATIONPOINT);
}
m_continuationPoints.Remove(continuationPoint);
}
// get the element queue.
Queue <ComDaBrowseElement> elements = null;
// get element from continuation point.
if (cp != null)
{
elements = cp.Elements;
}
// get list from cache.
else
{
elements = m_cache.BrowseForElements(session, itemId);
// check if nothing found.
if (elements == null)
{
throw ComUtils.CreateComException(ResultIds.E_UNKNOWNITEMID);
}
}
// apply filters.
List <ComDaBrowseElement> hits = new List <ComDaBrowseElement>();
while (elements.Count > 0)
{
ComDaBrowseElement hit = elements.Dequeue();
// apply name filter.
if (!String.IsNullOrEmpty(nameFilter))
{
if (!ComUtils.Match(hit.BrowseName, nameFilter, true))
{
continue;
}
}
// apply element filter
if (elementFilter == (int)OpcRcw.Da.OPCBROWSEFILTER.OPC_BROWSE_FILTER_BRANCHES)
{
if (!hit.HasChildren)
{
continue;
}
}
if (elementFilter == (int)OpcRcw.Da.OPCBROWSEFILTER.OPC_BROWSE_FILTER_ITEMS)
{
if (!hit.IsItem)
{
continue;
}
}
// check max reached.
if (maxElementsReturned > 0 && hits.Count == maxElementsReturned)
{
elements.Enqueue(hit);
cp = new ContinuationPoint();
cp.Id = Guid.NewGuid().ToString();
cp.Elements = elements;
m_continuationPoints.Add(cp.Id, cp);
revisedContinuationPoint = cp.Id;
break;
}
// add the result.
hits.Add(hit);
}
// return results.
return(hits);
}
/// <summary>
/// Return an IEnumString for a list of Areas as determined by the passed parameters.
/// </summary>
/// <param name="dwBrowseFilterType">
/// OPC_AREA - returns only areas.
/// OPC_SOURCE - returns only sources.</param>
/// <param name="szFilterCriteria">A server specific filter string. A pointer to a NULL string indicates no filtering.</param>
/// <param name="ppIEnumString">Where to save the returned interface pointer. NULL if the HRESULT is other than S_OK or S_FALSE.</param>
public void BrowseOPCAreas(
OPCAEBROWSETYPE dwBrowseFilterType,
string szFilterCriteria,
out OpcRcw.Comn.IEnumString ppIEnumString)
{
ppIEnumString = null;
if (dwBrowseFilterType != OPCAEBROWSETYPE.OPC_AREA && dwBrowseFilterType != OPCAEBROWSETYPE.OPC_SOURCE)
{
throw ComUtils.CreateComException("BrowseOPCAreas", ResultIds.E_INVALIDARG);
}
try
{
lock (m_lock)
{
// find the current node.
INode parent = null;
// ensure browse stack has been initialized.
if (m_browseStack.Count == 0)
{
parent = m_session.NodeCache.Find(Objects.Server);
m_browseStack.Push(parent);
}
parent = m_browseStack.Peek();
if (parent == null)
{
throw ComUtils.CreateComException("BrowseOPCAreas", ResultIds.E_FAIL);
}
List <string> names = new List <string>();
IList <INode> children;
////// find children.
children = m_session.NodeCache.Find(parent.NodeId, ReferenceTypes.HasEventSource, false, true); // This would also include
// the HasNotifier reference which is
// a subtype of HasEventSource
foreach (INode child in children)
{
// ignore external nodes.
if (child.NodeId.IsAbsolute)
{
continue;
}
// ignore non-objects/variables.
if ((child.NodeClass & (NodeClass.Object | NodeClass.Variable)) == 0)
{
continue;
}
// ignore duplicate browse names.
if (names.Contains(child.BrowseName.ToString()))
{
continue;
}
// For a node to be an area, it has to have the 'HasNotifier' reference and must
// allow event notification (the EventNotifier attribute is set to SubscribeToEvents)
// For a node to be a source, it should be the target of the HasEventSource reference
if (IsValidNode((NodeId)child.NodeId, child.BrowseName.ToString(), dwBrowseFilterType))
{
if (String.IsNullOrEmpty(szFilterCriteria))
{
names.Add(child.BrowseName.ToString());
}
else
{
// apply filters
if (ComUtils.Match(child.BrowseName.ToString(), szFilterCriteria, true))
{
names.Add(child.BrowseName.ToString());
}
}
}
}
// create enumerator.
ppIEnumString = (OpcRcw.Comn.IEnumString) new EnumString(names);
}
}
catch (Exception e)
{
Utils.Trace(e, "Unexpected error in BrowseOPCAreas");
throw ComUtils.CreateComException(e);
}
}