QMqtt Namespace
Contains miscellaneous identifiers used throughout the Qt MQTT module. More...
| Header: | #include <QMqtt> |
| CMake: | find_package(Qt6 REQUIRED COMPONENTS Mqtt) target_link_libraries(mytarget PRIVATE Qt6::Mqtt) |
| qmake: | QT += mqtt |
Types
| enum class | MessageStatus { Unknown, Published, Acknowledged, Received, Released, Completed } |
| enum class | PayloadFormatIndicator { Unspecified, UTF8Encoded } |
| enum class | ReasonCode { Success, SubscriptionQoSLevel0, SubscriptionQoSLevel1, SubscriptionQoSLevel2, NoMatchingSubscriber, …, WildCardSubscriptionsNotSupported } |
Type Documentation
enum class QMqtt::MessageStatus
This enum type specifies the available states of a message. Depending on the QoS and role of the client, different message statuses are expected.
| Constant | Value | Description |
|---|---|---|
QMqtt::MessageStatus::Unknown | 0 | The message status is unknown. |
QMqtt::MessageStatus::Published | 1 | The client received a message for one of its subscriptions. This applies to QoS levels 1 and 2. |
QMqtt::MessageStatus::Acknowledged | 2 | A message has been acknowledged. This applies to QoS 1 and states that the message handling has been finished from the client side. |
QMqtt::MessageStatus::Received | 3 | A message has been received. This applies to QoS 2. |
QMqtt::MessageStatus::Released | 4 | A message has been released. This applies to QoS 2. For a publisher the message handling has been finished. |
QMqtt::MessageStatus::Completed | 5 | A message has been completed. This applies to QoS 2 and states that the message handling has been finished from the client side. |
enum class QMqtt::PayloadFormatIndicator
The payload format provides information on the content of a message. This can help other clients to handle the message faster.
| Constant | Value | Description |
|---|---|---|
QMqtt::PayloadFormatIndicator::Unspecified | 0 | The format is not specified. |
QMqtt::PayloadFormatIndicator::UTF8Encoded | 1 | The payload of the message is formatted as UTF-8 Encoded Character Data. |
enum class QMqtt::ReasonCode
This enum type specifies the available error codes.
| Constant | Value | Description |
|---|---|---|
QMqtt::ReasonCode::Success | 0 | The specified action has succeeded. |
QMqtt::ReasonCode::SubscriptionQoSLevel0 | 0 | A subscription with QoS level 0 has been created. |
QMqtt::ReasonCode::SubscriptionQoSLevel1 | 0x01 | A subscription with QoS level 1 has been created. |
QMqtt::ReasonCode::SubscriptionQoSLevel2 | 0x02 | A subscription with QoS level 2 has been created. |
QMqtt::ReasonCode::NoMatchingSubscriber | 0x10 | The message has been accepted by the server, but there are no subscribers to receive this message. A broker may send this reason code instead of Success. |
QMqtt::ReasonCode::NoSubscriptionExisted (since Qt 5.15) | 0x11 | No matching Topic Filter is being used by the Client. |
QMqtt::ReasonCode::ContinueAuthentication (since Qt 5.15) | 0x18 | Continue the authentication with another step. |
QMqtt::ReasonCode::ReAuthenticate (since Qt 5.15) | 0x19 | Initiate a re-authentication. |
QMqtt::ReasonCode::UnspecifiedError | 0x80 | An unspecified error occurred. |
QMqtt::ReasonCode::MalformedPacket | 0x81 | The packet sent to the server is invalid. |
QMqtt::ReasonCode::ProtocolError | 0x82 | A protocol error has occurred. In most cases, this will cause the server to disconnect the client. |
QMqtt::ReasonCode::ImplementationSpecificError | 0x83 | The packet is valid, but the recipient rejects it. |
QMqtt::ReasonCode::UnsupportedProtocolVersion | 0x84 | The requested protocol version is not supported by the server. |
QMqtt::ReasonCode::InvalidClientId | 0x85 | The client ID is invalid. |
QMqtt::ReasonCode::InvalidUserNameOrPassword | 0x86 | The username or password specified is invalid. |
QMqtt::ReasonCode::NotAuthorized | 0x87 | The client is not authorized for the specified action. |
QMqtt::ReasonCode::ServerNotAvailable | 0x88 | The server to connect to is not available. |
QMqtt::ReasonCode::ServerBusy | 0x89 | The server to connect to is not available. The client is asked to try at a later time. |
QMqtt::ReasonCode::ClientBanned | 0x8A | The client has been banned from the server. |
QMqtt::ReasonCode::InvalidAuthenticationMethod | 0x8C | The authentication method specified is invalid. |
QMqtt::ReasonCode::InvalidTopicFilter | 0x8F | The topic filter specified is invalid. |
QMqtt::ReasonCode::InvalidTopicName | 0x90 | The topic name specified is invalid. |
QMqtt::ReasonCode::MessageIdInUse | 0x91 | The message ID used in the previous packet is already in use. |
QMqtt::ReasonCode::MessageIdNotFound | 0x92 | The message ID used in the previous packet has not been found. |
QMqtt::ReasonCode::PacketTooLarge | 0x95 | The packet received is too large. See also QMqttServerConnectionProperties::maximumPacketSize(). |
QMqtt::ReasonCode::QuotaExceeded | 0x97 | An administratively imposed limit has been exceeded. |
QMqtt::ReasonCode::InvalidPayloadFormat | 0x99 | The payload format is invalid. See also QMqttPublishProperties::payloadFormatIndicator(). |
QMqtt::ReasonCode::RetainNotSupported | 0x9A | The server does not support retained messages. See also QMqttServerConnectionProperties::retainAvailable(). |
QMqtt::ReasonCode::QoSNotSupported | 0x9B | The QoS level requested is not supported. See also QMqttServerConnectionProperties::maximumQoS(). |
QMqtt::ReasonCode::UseAnotherServer | 0x9C | The server the client tries to connect to is not available. See also QMqttServerConnectionProperties::serverReference(). |
QMqtt::ReasonCode::ServerMoved | 0x9D | The server the client tries to connect to has moved to a new address. See also QMqttServerConnectionProperties::serverReference(). |
QMqtt::ReasonCode::SharedSubscriptionsNotSupported | 0x9E | Shared subscriptions are not supported. See also QMqttServerConnectionProperties::sharedSubscriptionSupported(). |
QMqtt::ReasonCode::ExceededConnectionRate | 0x9F | The connection rate limit has been exceeded. |
QMqtt::ReasonCode::SubscriptionIdsNotSupported | 0xA1 | Subscription IDs are not supported. See also QMqttServerConnectionProperties::subscriptionIdentifierSupported(). |
QMqtt::ReasonCode::WildCardSubscriptionsNotSupported | 0xA2 | Subscriptions using wildcards are not supported by the server. See also QMqttServerConnectionProperties::wildcardSupported(). |
Not all values are available in every use case. Especially, some servers will reject a reason code not suited for a specific command. See below table to highlight expected reason codes for specific actions.
| Reason Code | Connect Properties | Subscription Properties | Message Properties |
|---|---|---|---|
| Success | X | X | X |
| SubscriptionQoSLevel0 | X | ||
| SubscriptionQoSLevel1 | X | ||
| SubscriptionQoSLevel2 | X | ||
| NoMatchingSubscriber | X | ||
| UnspecifiedError | X | X | X |
| MalformedPacket | X | ||
| ProtocolError | X | ||
| ImplementationSpecificError | X | X | X |
| UnsupportedProtocolVersion | X | ||
| InvalidClientId | X | ||
| InvalidUserNameOrPassword | X | ||
| NotAuthorized | X | X | X |
| ServerNotAvailable | X | ||
| ServerBusy | X | ||
| ClientBanned | X | ||
| InvalidAuthenticationMethod | X | ||
| InvalidTopicFilter | X | ||
| InvalidTopicName | X | X | |
| MessageIdInUse | X | X | |
| MessageIdNotFound | X | ||
| PacketTooLarge | X | ||
| QuotaExceeded | X | X | X |
| InvalidPayloadFormat | X | X | |
| RetainNotSupported | X | ||
| QoSNotSupported | X | ||
| UseAnotherServer | X | ||
| ServerMoved | X | ||
| SharedSubscriptionsNotSupported | X | ||
| ExceededConnectionRate | X | ||
| SubscriptionIdsNotSupported | X | ||
| WildCardSubscriptionsNotSupported | X |
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