EventFilter#
Defines an EventFilter
for a monitored item. More…
Synopsis#
Functions#
def
__lshift__
(whereClauseElement)def
__lshift__
(selectClauseElement)def
__eq__
(rhs)def
selectClauses
()def
selectClausesRef
()def
setSelectClauses
(selectClauses)def
setWhereClause
(whereClause)def
whereClause
()def
whereClauseRef
()
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
An event filter is required for monitoring events on the server. It consists of select
clauses and a where
clause.
The select
clauses are used to specify the data the user wants to receive when an event occurs. It consists of QOpcUaSimpleAttributeOperand
simple attribute operands which select attributes of child nodes of an event type, for example the value attribute of the “Message” property of BaseEventType.
The where
clause is used to restrict the reported events by matching against certain criteria. Several operators and four different operand types allow filtering based on the values of the attributes of the child nodes of an event type.
Filters can be constructed using the setter or the streaming operator. Streaming a QOpcUaSimpleAttributeOperand
into an event filter adds a new select
clause to the filter, a QOpcUaContentFilterElement
is appended to the where
clause. A content filter element can be constructed by streaming operands of the types QOpcUaLiteralOperand
, QOpcUaElementOperand
, QOpcUaAttributeOperand
and QOpcUaSimpleAttributeOperand
and an operator into a content filter element. Only the last operator is used, previous operators will be discarded.
The following EventFilter
tells the server to report the value of the “Message” field for events that have a “Severity” field with value >= 500:
QOpcUaMonitoringParameters::EventFilter filter; filter << QOpcUaSimpleAttributeOperand("Message"); // Select clause of the filter QOpcUaContentFilterElement condition; condition << QOpcUaContentFilterElement::FilterOperator::GreaterThanOrEqual; condition << QOpcUaSimpleAttributeOperand("Severity"); condition << QOpcUaLiteralOperand(500, QOpcUa::Types::UInt16); filter << condition; // Where clause of the filter
For a more complex example with two conditions, see QOpcUaElementOperand
.
- class PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter#
PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter(arg__1)
- Parameters:
arg__1 –
PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter
Constructs an event filter from rhs
.
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.__lshift__(whereClauseElement)#
- Parameters:
whereClauseElement –
PySide6.QtOpcUa.QOpcUaContentFilterElement
- Return type:
Adds the content filter element whereClauseElement
to the where clause of this event filter.
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.__lshift__(selectClauseElement)
- Parameters:
selectClauseElement –
PySide6.QtOpcUa.QOpcUaSimpleAttributeOperand
- Return type:
Adds the simple attribute operand selectClauseElement
to the select clause of this content filter element.
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.__eq__(rhs)#
- Parameters:
rhs –
PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter
- Return type:
bool
Returns true
if this event filter has the same value as rhs
.
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.selectClauses()#
Returns the selected event fields that shall be included when a new event is reported.
See also
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.selectClausesRef()#
Returns a reference to the select clauses.
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.setSelectClauses(selectClauses)#
- Parameters:
selectClauses –
Sets the select clauses to selectClauses
.
See also
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.setWhereClause(whereClause)#
- Parameters:
whereClause –
Sets the where clause to whereClause
.
See also
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.whereClause()#
Returns the content filter used to restrict the reported events to events matching certain criteria.
See also
- PySide6.QtOpcUa.QOpcUaMonitoringParameters.EventFilter.whereClauseRef()#
Returns a reference to the where clause.
See also