/// <summary>
/// Constructs the event filter for the subscription.
/// </summary>
/// <returns>The event filter.</returns>
public EventFilter ConstructFilter(Session session)
{
EventFilter filter = new EventFilter();
// the select clauses specify the values returned with each event notification.
filter.SelectClauses = SelectClauses;
// the where clause restricts the events returned by the server.
// it works a lot like the WHERE clause in a SQL statement and supports
// arbitrary expession trees where the operands are literals or event fields.
ContentFilter whereClause = new ContentFilter();
// the code below constructs a filter that looks like this:
// (Severity >= X OR LastSeverity >= X) AND (SuppressedOrShelved == False) AND (OfType(A) OR OfType(B))
// add the severity.
ContentFilterElement element1 = null;
ContentFilterElement element2 = null;
if (Severity > EventSeverity.Min)
{
// select the Severity property of the event.
SimpleAttributeOperand operand1 = new SimpleAttributeOperand();
operand1.TypeDefinitionId = ObjectTypeIds.BaseEventType;
operand1.BrowsePath.Add(BrowseNames.Severity);
operand1.AttributeId = Attributes.Value;
// specify the value to compare the Severity property with.
LiteralOperand operand2 = new LiteralOperand();
operand2.Value = new Variant((ushort)Severity);
// specify that the Severity property must be GreaterThanOrEqual the value specified.
element1 = whereClause.Push(FilterOperator.GreaterThanOrEqual, operand1, operand2);
}
// add the suppressed or shelved.
if (!IgnoreSuppressedOrShelved)
{
// select the SuppressedOrShelved property of the event.
SimpleAttributeOperand operand1 = new SimpleAttributeOperand();
operand1.TypeDefinitionId = ObjectTypeIds.BaseEventType;
operand1.BrowsePath.Add(BrowseNames.SuppressedOrShelved);
operand1.AttributeId = Attributes.Value;
// specify the value to compare the Severity property with.
LiteralOperand operand2 = new LiteralOperand();
operand2.Value = new Variant(false);
// specify that the Severity property must Equal the value specified.
element2 = whereClause.Push(FilterOperator.Equals, operand1, operand2);
// chain multiple elements together with an AND clause.
if (element1 != null)
{
element1 = whereClause.Push(FilterOperator.And, element1, element2);
}
else
{
element1 = element2;
}
}
// add the event types.
if (EventTypes != null && EventTypes.Count > 0)
{
element2 = null;
// save the last element.
for (int ii = 0; ii < EventTypes.Count; ii++)
{
// for this example uses the 'OfType' operator to limit events to thoses with specified event type.
LiteralOperand operand1 = new LiteralOperand();
operand1.Value = new Variant(EventTypes[ii]);
ContentFilterElement element3 = whereClause.Push(FilterOperator.OfType, operand1);
// need to chain multiple types together with an OR clause.
if (element2 != null)
{
element2 = whereClause.Push(FilterOperator.Or, element2, element3);
}
else
{
element2 = element3;
}
}
// need to link the set of event types with the previous filters.
if (element1 != null)
{
whereClause.Push(FilterOperator.And, element1, element2);
}
}
filter.WhereClause = whereClause;
// return filter.
return(filter);
}
/// <summary>
/// Returns the where clause defined by the filter declaration.
/// </summary>
private ContentFilter GetWhereClause()
{
ContentFilter whereClause = new ContentFilter();
ContentFilterElement element1 = null;
// filter by source.
if (SelectedSources != null && SelectedSources.Count > 0)
{
SimpleAttributeOperand operand1 = new SimpleAttributeOperand();
operand1.TypeDefinitionId = Opc.Ua.ObjectTypeIds.BaseEventType;
operand1.AttributeId = Attributes.Value;
operand1.BrowsePath.Add(new QualifiedName(Opc.Ua.BrowseNames.SourceNode));
for (int ii = 0; ii < SelectedSources.Count; ii++)
{
LiteralOperand operand2 = new LiteralOperand();
operand2.Value = SelectedSources[ii];
ContentFilterElement element2 = whereClause.Push(FilterOperator.Equals, operand1, operand2);
element1 = (element1 != null)?whereClause.Push(FilterOperator.Or, element1, element2):element2;
}
}
// add condition/tracking categories if no other categories selected.
if (RevisedCategories == null || RevisedCategories.Count == 0)
{
if (EventTypes == (OpcRcw.Ae.Constants.SIMPLE_EVENT | OpcRcw.Ae.Constants.TRACKING_EVENT))
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.ConditionType);
ContentFilterElement element3 = whereClause.Push(FilterOperator.Not, element2);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element3) : element3;
}
else if (EventTypes == (OpcRcw.Ae.Constants.SIMPLE_EVENT | OpcRcw.Ae.Constants.CONDITION_EVENT))
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.AuditEventType);
ContentFilterElement element3 = whereClause.Push(FilterOperator.Not, element2);
ContentFilterElement element4 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.TransitionEventType);
ContentFilterElement element5 = whereClause.Push(FilterOperator.Not, element4);
ContentFilterElement element6 = whereClause.Push(FilterOperator.Or, element3, element5);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element6) : element6;
}
else if (EventTypes == (OpcRcw.Ae.Constants.TRACKING_EVENT | OpcRcw.Ae.Constants.CONDITION_EVENT))
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.AuditEventType);
ContentFilterElement element3 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.TransitionEventType);
ContentFilterElement element4 = whereClause.Push(FilterOperator.Or, element2, element3);
ContentFilterElement element5 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.ConditionType);
ContentFilterElement element6 = whereClause.Push(FilterOperator.Or, element4, element5);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element6) : element6;
}
else if (EventTypes == OpcRcw.Ae.Constants.TRACKING_EVENT)
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.AuditEventType);
ContentFilterElement element3 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.TransitionEventType);
ContentFilterElement element4 = whereClause.Push(FilterOperator.Or, element2, element3);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element4) : element4;
}
else if (EventTypes == OpcRcw.Ae.Constants.CONDITION_EVENT)
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.ConditionType);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element2) : element2;
}
else if (EventTypes == OpcRcw.Ae.Constants.SIMPLE_EVENT)
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.AuditEventType);
ContentFilterElement element3 = whereClause.Push(FilterOperator.Not, element2);
ContentFilterElement element4 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.TransitionEventType);
ContentFilterElement element5 = whereClause.Push(FilterOperator.Not, element4);
ContentFilterElement element6 = whereClause.Push(FilterOperator.Or, element3, element5);
ContentFilterElement element7 = whereClause.Push(FilterOperator.OfType, Opc.Ua.ObjectTypeIds.ConditionType);
ContentFilterElement element8 = whereClause.Push(FilterOperator.Not, element7);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element8) : element8;
}
}
// filter by event type.
if (RevisedCategories.Count > 0)
{
SimpleAttributeOperand operand1 = new SimpleAttributeOperand();
operand1.TypeDefinitionId = Opc.Ua.ObjectTypeIds.BaseEventType;
operand1.AttributeId = Attributes.Value;
operand1.BrowsePath.Add(new QualifiedName(Opc.Ua.BrowseNames.EventType));
ContentFilterElement element3 = null;
for (int ii = 0; ii < RevisedCategories.Count; ii++)
{
ContentFilterElement element2 = whereClause.Push(FilterOperator.Equals, operand1, RevisedCategories[ii].TypeId);
element3 = (element3 != null) ? whereClause.Push(FilterOperator.Or, element2, element3) : element2;
}
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element3) : element3;
}
// filter by severity.
if (LowSeverity > 1 || HighSeverity < 1000)
{
SimpleAttributeOperand operand1 = new SimpleAttributeOperand();
operand1.TypeDefinitionId = Opc.Ua.ObjectTypeIds.BaseEventType;
operand1.AttributeId = Attributes.Value;
operand1.BrowsePath.Add(new QualifiedName(Opc.Ua.BrowseNames.Severity));
if (LowSeverity > 1)
{
LiteralOperand operand2 = new LiteralOperand();
operand2.Value = LowSeverity;
ContentFilterElement element2 = whereClause.Push(FilterOperator.GreaterThanOrEqual, operand1, operand2);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element2) : element2;
}
if (HighSeverity < 1000)
{
LiteralOperand operand2 = new LiteralOperand();
operand2.Value = HighSeverity;
ContentFilterElement element2 = whereClause.Push(FilterOperator.LessThanOrEqual, operand1, operand2);
element1 = (element1 != null) ? whereClause.Push(FilterOperator.And, element1, element2) : element2;
}
}
return(whereClause);
}
/// <summary>
/// Displays the dialog.
/// </summary>
public FilterOperand ShowDialog(
Session session,
IList <ContentFilterElement> elements,
int index,
FilterOperand operand)
{
if (session == null)
{
throw new ArgumentNullException("session");
}
if (elements == null)
{
throw new ArgumentNullException("elements");
}
m_session = session;
TypeDefinitionIdCTRL.Browser = new Browser(session);
TypeDefinitionIdCTRL.RootId = ObjectTypes.BaseEventType;
OperandTypeCB.SelectedItem = typeof(LiteralOperand).Name;
if (operand != null)
{
OperandTypeCB.SelectedItem = operand.GetType().Name;
}
ElementsCB.Items.Clear();
for (int ii = index + 1; ii < elements.Count; ii++)
{
ElementsCB.Items.Add(elements[ii].ToString(m_session.NodeCache));
}
ElementOperand elementOperand = operand as ElementOperand;
if (elementOperand != null)
{
ElementsCB.SelectedIndex = (int)elementOperand.Index - index - 1;
}
AttributeOperand attributeOperand = operand as AttributeOperand;
if (attributeOperand != null)
{
TypeDefinitionIdCTRL.Identifier = attributeOperand.NodeId;
BrowsePathTB.Text = attributeOperand.BrowsePath.Format(session.NodeCache.TypeTree);
AttributeIdCB.SelectedItem = Attributes.GetBrowseName(attributeOperand.AttributeId);
IndexRangeTB.Text = attributeOperand.IndexRange;
AliasTB.Text = attributeOperand.Alias;
}
LiteralOperand literalOperand = operand as LiteralOperand;
if (literalOperand != null)
{
NodeId datatypeId = TypeInfo.GetDataTypeId(literalOperand.Value.Value);
DataTypeCB.SelectedItem = TypeInfo.GetBuiltInType(datatypeId);
StringBuilder buffer = new StringBuilder();
Array array = literalOperand.Value.Value as Array;
if (array != null)
{
for (int ii = 0; ii < array.Length; ii++)
{
if (ii > 0)
{
buffer.Append("\r\n");
}
buffer.AppendFormat("{0}", new Variant(array.GetValue(ii)));
}
}
else
{
buffer.AppendFormat("{0}", literalOperand.Value);
}
ValueTB.Text = buffer.ToString();
}
if (ShowDialog() != DialogResult.OK)
{
return(null);
}
return(operand);
}
