QOpcUaHistoryReadResponse Class

This class is used for requesting historical data and storing the results. More...

Header:	#include <QOpcUaHistoryReadResponse>
CMake:	find_package(Qt6 REQUIRED COMPONENTS OpcUa) target_link_libraries(mytarget PRIVATE Qt6::OpcUa)
qmake:	QT += opcua
Since:	Qt 6.3
Inherits:	QObject

List of all members, including inherited members

Public Types

enum class State { Unknown, Reading, Finished, MoreDataAvailable, Error }

Public Functions

virtual	~QOpcUaHistoryReadResponse()
QList<QOpcUaHistoryData>	data() const
bool	hasMoreData() const
bool	readMoreData()
bool	releaseContinuationPoints()
QOpcUa::UaStatusCode	serviceResult() const
QOpcUaHistoryReadResponse::State	state() const

Signals

void	readHistoryDataFinished(const QList<QOpcUaHistoryData> &results, QOpcUa::UaStatusCode serviceResult)
void	stateChanged(QOpcUaHistoryReadResponse::State state)

Detailed Description

A historical data request to an OPC UA server can be specified by a QOpcUaHistoryReadRawRequest.

Objects of this class and the statuscode of the request are returned in the QOpcUaHistoryReadResponse::readHistoryDataFinished(const QList<QOpcUaHistoryData> &results, QOpcUa::UaStatusCode serviceResult) signal and contain the result of a request.

Member Type Documentation

enum class QOpcUaHistoryReadResponse::State

This enum specifies the state the response is in.

Constant	Value
`QOpcUaHistoryReadResponse::State::Unknown`	`0`
`QOpcUaHistoryReadResponse::State::Reading`	`1`
`QOpcUaHistoryReadResponse::State::Finished`	`2`
`QOpcUaHistoryReadResponse::State::MoreDataAvailable`	`3`
`QOpcUaHistoryReadResponse::State::Error`	`4`

Member Function Documentation

`[signal]` void QOpcUaHistoryReadResponse::readHistoryDataFinished(const QList<QOpcUaHistoryData> &results, QOpcUa::UaStatusCode serviceResult)

This signal is emitted when a historical data request is finished. It adds to results and sets serviceResult to indicate the state of the result.

See also data() and serviceResult().

`[signal]` void QOpcUaHistoryReadResponse::stateChanged(QOpcUaHistoryReadResponse::State state)

This signal is emitted when the of a historical data request is changed. It sets state to indicate the state of the change.

`[virtual]` QOpcUaHistoryReadResponse::~QOpcUaHistoryReadResponse()

The destructor for QOpcUaHistoryReadResponse

QList<QOpcUaHistoryData> QOpcUaHistoryReadResponse::data() const

Returns a list which contains the requested historic data.

bool QOpcUaHistoryReadResponse::hasMoreData() const

Returns true if there are more values available from the historic data request.

bool QOpcUaHistoryReadResponse::readMoreData()

Returns true if a read request for more historic values is successfully dispatched.

bool QOpcUaHistoryReadResponse::releaseContinuationPoints()

Releases the continuation points and sets the request as finished. Returns true if the pending request has been successfully finished; otherwise returns false.

QOpcUa::UaStatusCode QOpcUaHistoryReadResponse::serviceResult() const

Returns the serviceresult of the historic data request.

QOpcUaHistoryReadResponse::State QOpcUaHistoryReadResponse::state() const

Returns the current state of historic data request.

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