QMqttServerConnectionProperties Class
The QMqttServerConnectionProperties class represents configuration options of a server a QMqttClient is connected to. More...
| Header: | #include <QMqttServerConnectionProperties> |
| CMake: | find_package(Qt6 REQUIRED COMPONENTS Mqtt) target_link_libraries(mytarget PRIVATE Qt6::Mqtt) |
| qmake: | QT += mqtt |
| Since: | Qt 5.12 |
| Inherits: | QMqttConnectionProperties |
Public Types
| enum | ServerPropertyDetail { None, SessionExpiryInterval, MaximumReceive, MaximumQoS, RetainAvailable, …, AuthenticationData } |
| flags | ServerPropertyDetails |
Public Functions
| QMqttServerConnectionProperties::ServerPropertyDetails | availableProperties() const |
| bool | clientIdAssigned() const |
| bool | isValid() const |
| quint8 | maximumQoS() const |
| QString | reason() const |
| QMqtt::ReasonCode | reasonCode() const |
| QString | responseInformation() const |
| bool | retainAvailable() const |
| quint16 | serverKeepAlive() const |
| QString | serverReference() const |
| bool | sharedSubscriptionSupported() const |
| bool | subscriptionIdentifierSupported() const |
| bool | wildcardSupported() const |
Detailed Description
When a connection has been established the server might send additional details about the connection properties. Use availableProperties() to identify properties set by the server. If a property is not set by the server, default values are assumed and can be obtained by invoking access functions of this instance.
Note: Connection 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 QMqttServerConnectionProperties::ServerPropertyDetail
flags QMqttServerConnectionProperties::ServerPropertyDetails
This enum type specifies the available properties set by the server or the client after establishing a connection.
| Constant | Value | Description |
|---|---|---|
QMqttServerConnectionProperties::None | 0x00000000 | No property has been specified. |
QMqttServerConnectionProperties::SessionExpiryInterval | 0x00000001 | The number of seconds the server keeps the session after a disconnect. |
QMqttServerConnectionProperties::MaximumReceive | 0x00000002 | The maximum number of QoS 1 and 2 message the server is capable of managing concurrently. |
QMqttServerConnectionProperties::MaximumQoS | 0x00000004 | The maximum QoS level the server can understand. |
QMqttServerConnectionProperties::RetainAvailable | 0x00000010 | Specifies whether retained messages are supported. |
QMqttServerConnectionProperties::MaximumPacketSize | 0x00000020 | Specifies the maximum packet size including the message header and properties. |
QMqttServerConnectionProperties::AssignedClientId | 0x00000040 | Specifies whether the server assigned a client identifier. |
QMqttServerConnectionProperties::MaximumTopicAlias | 0x00000080 | Specifies the maximum amount of topic aliases. |
QMqttServerConnectionProperties::ReasonString | 0x00000100 | Specifies a string providing more details on connection state. |
QMqttServerConnectionProperties::UserProperty | 0x00000200 | Specifies additional user properties. |
QMqttServerConnectionProperties::WildCardSupported | 0x00000400 | Specifies whether the server supports wildcard subscriptions. |
QMqttServerConnectionProperties::SubscriptionIdentifierSupport | 0x00000800 | Specifies whether the server supports subscription identifiers. |
QMqttServerConnectionProperties::SharedSubscriptionSupport | 0x00001000 | Specifies whether the server supports shared subscriptions. |
QMqttServerConnectionProperties::ServerKeepAlive | 0x00002000 | Specifies the number of seconds the server expects a keep alive packet from the client. |
QMqttServerConnectionProperties::ResponseInformation | 0x00004000 | Specifies the response information. |
QMqttServerConnectionProperties::ServerReference | 0x00008000 | Specifies an alternative server address for the client to connect to. |
QMqttServerConnectionProperties::AuthenticationMethod | 0x00010000 | Specifies the authentication method. |
QMqttServerConnectionProperties::AuthenticationData | 0x00020000 | Specifies the authentication data. |
The ServerPropertyDetails type is a typedef for QFlags<ServerPropertyDetail>. It stores an OR combination of ServerPropertyDetail values.
Member Function Documentation
QMqttServerConnectionProperties::ServerPropertyDetails QMqttServerConnectionProperties::availableProperties() const
Returns the available properties specified by the server.
bool QMqttServerConnectionProperties::clientIdAssigned() const
Returns true if the server assigned a new client identifier to the client.
See also QMqttClient::clientId().
bool QMqttServerConnectionProperties::isValid() const
Returns true if the server provided properties as part of the connection aknowledgment. Returns false if no properties have been provided.
quint8 QMqttServerConnectionProperties::maximumQoS() const
Returns the maximum QoS level the server supports for publishing messages. Publishing messages with QoS level exceeding the maximum QoS level reported by the server is a protocol violation.
If the client does not need to support QoS 1 or QoS 2, it should restrict the maximum QoS level in any subscription it does to a value it can support; the server would then publish messages with the maximum of supported and restricted QoS levels.
The default value is 2.
See also QMqttClient::publish() and QMqttClient::subscribe().
QString QMqttServerConnectionProperties::reason() const
Returns the reason string associated with this response.
QMqtt::ReasonCode QMqttServerConnectionProperties::reasonCode() const
Returns the reason code associated with this response.
QString QMqttServerConnectionProperties::responseInformation() const
Returns the response information.
bool QMqttServerConnectionProperties::retainAvailable() const
Returns true if the server accepts retained messages. The default value is true.
quint16 QMqttServerConnectionProperties::serverKeepAlive() const
Returns the number of seconds the server requested as keep alive. This overwrites the keep alive being set from the client side.
See also QMqttClient::setKeepAlive().
QString QMqttServerConnectionProperties::serverReference() const
Returns a server address which can be used by the client alternatively to connect to. Typically, this is used together with the reason code 0x9c (Use another server) or 0x9c (Server moved).
bool QMqttServerConnectionProperties::sharedSubscriptionSupported() const
Returns true if the server accepts shared subscriptions. The default value is true.
bool QMqttServerConnectionProperties::subscriptionIdentifierSupported() const
Returns true if the server accepts subscription identifiers. Subscription identifiers can be passed to the server when creating a new subscription.
The default value is true.
See also QMqttSubscriptionProperties::setSubscriptionIdentifier().
bool QMqttServerConnectionProperties::wildcardSupported() const
Returns true if the server accepts subscriptions including wildcards. The default value is true.