QMqttPublishProperties Class
The QMqttPublishProperties class represents configuration options for sending or receiving a message. More...
| Header: | #include <QMqttPublishProperties> |
| CMake: | find_package(Qt6 REQUIRED COMPONENTS Mqtt) target_link_libraries(mytarget PRIVATE Qt6::Mqtt) |
| qmake: | QT += mqtt |
Public Types
| enum | PublishPropertyDetail { None, PayloadFormatIndicator, MessageExpiryInterval, TopicAlias, ResponseTopic, …, ContentType } |
| flags | PublishPropertyDetails |
Public Functions
| QMqttPublishProperties::PublishPropertyDetails | availableProperties() const |
| QString | contentType() const |
| QByteArray | correlationData() const |
| quint32 | messageExpiryInterval() const |
| QMqtt::PayloadFormatIndicator | payloadFormatIndicator() const |
| QString | responseTopic() const |
| void | setContentType(const QString &type) |
| void | setCorrelationData(const QByteArray &correlation) |
| void | setMessageExpiryInterval(quint32 interval) |
| void | setPayloadFormatIndicator(QMqtt::PayloadFormatIndicator indicator) |
| void | setResponseTopic(const QString &topic) |
| void | setSubscriptionIdentifiers(const QList<quint32> &ids) |
| void | setTopicAlias(quint16 alias) |
| void | setUserProperties(const QMqttUserProperties &properties) |
| QList<quint32> | subscriptionIdentifiers() const |
| quint16 | topicAlias() const |
| QMqttUserProperties | userProperties() const |
Detailed Description
Invoking QMqttClient::publish() to send a message to a broker can include QMqttPublishProperties to provide additional arguments on how the message should be treated on the broker.
Furthermore receiving a message by an instantiated subscription might contain publish properties which have been forwarded or adapted by the server.
Note: Publish properties are part of the MQTT 5.0 specification and cannot be used when connecting with a lower protocol level. See QMqttClient::ProtocolVersion for more information.
Member Type Documentation
enum QMqttPublishProperties::PublishPropertyDetail
flags QMqttPublishProperties::PublishPropertyDetails
This enum type specifies the available properties set by the server or the client when creating a message.
| Constant | Value | Description |
|---|---|---|
QMqttPublishProperties::None | 0x00000000 | No property has been specified. |
QMqttPublishProperties::PayloadFormatIndicator | 0x00000001 | The type of content of the message. |
QMqttPublishProperties::MessageExpiryInterval | 0x00000002 | The duration a message is valid. |
QMqttPublishProperties::TopicAlias | 0x00000004 | The topic alias for this message. |
QMqttPublishProperties::ResponseTopic | 0x00000008 | The topic the receipient should respond to. |
QMqttPublishProperties::CorrelationData | 0x00000010 | An identifier of the response message. |
QMqttPublishProperties::UserProperty | 0x00000020 | Additional properties set by the user. |
QMqttPublishProperties::SubscriptionIdentifier | 0x00000040 | An identifier of subscriptions matching the publication. |
QMqttPublishProperties::ContentType | 0x00000080 | A description of the content of the message. |
The PublishPropertyDetails type is a typedef for QFlags<PublishPropertyDetail>. It stores an OR combination of PublishPropertyDetail values.
Member Function Documentation
QMqttPublishProperties::PublishPropertyDetails QMqttPublishProperties::availableProperties() const
Returns the available properties specified in this instance. When a message is created, it does not need to include all properties. This function serves as an indicator of those properties which have been explicitly set.
QString QMqttPublishProperties::contentType() const
Returns the content type of the message.
See also setContentType().
QByteArray QMqttPublishProperties::correlationData() const
Returns the correlation data.
See also setCorrelationData().
quint32 QMqttPublishProperties::messageExpiryInterval() const
Returns the message expiry interval. This value specifies the number of seconds a server is allowed to forward the message. If the interval expires, the server must delete the message and abort publishing it.
See also setMessageExpiryInterval().
QMqtt::PayloadFormatIndicator QMqttPublishProperties::payloadFormatIndicator() const
Returns the payload format indicator.
See also setPayloadFormatIndicator().
QString QMqttPublishProperties::responseTopic() const
Returns the response topic a user should use as a follow up to a request.
See also setResponseTopic().
void QMqttPublishProperties::setContentType(const QString &type)
Sets the content type of the message to type.
See also contentType().
void QMqttPublishProperties::setCorrelationData(const QByteArray &correlation)
Sets the correlation data to correlation.
See also correlationData().
void QMqttPublishProperties::setMessageExpiryInterval(quint32 interval)
Sets the message expiry interval to interval.
See also messageExpiryInterval().
void QMqttPublishProperties::setPayloadFormatIndicator(QMqtt::PayloadFormatIndicator indicator)
Sets the payload format indicator to indicator.
See also payloadFormatIndicator().
void QMqttPublishProperties::setResponseTopic(const QString &topic)
Sets the response topic to topic.
See also responseTopic().
void QMqttPublishProperties::setSubscriptionIdentifiers(const QList<quint32> &ids)
Sets the subscription identifiers to ids.
See also subscriptionIdentifiers().
void QMqttPublishProperties::setTopicAlias(quint16 alias)
Sets the topic alias for publishing a message to alias. A topic alias value must be greater than zero and less than the maximum topic alias specified by the server.
See also topicAlias() and QMqttServerConnectionProperties::maximumTopicAlias().
void QMqttPublishProperties::setUserProperties(const QMqttUserProperties &properties)
Sets the user properties of a message to properties.
See also userProperties().
QList<quint32> QMqttPublishProperties::subscriptionIdentifiers() const
Returns the subscription identifiers of subscriptions matching the topic filter of the message.
See also setSubscriptionIdentifiers().
quint16 QMqttPublishProperties::topicAlias() const
Returns the topic alias used for publishing a message.
See also setTopicAlias().
QMqttUserProperties QMqttPublishProperties::userProperties() const
Returns the user properties of a message.
See also setUserProperties().
© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.
