Implements: IMessageQueueConnection, IReferenceable, IConfigurable, IOpenable
Description
The MqttConnection class allows you to create MQTT connections using the default driver.
Configuration parameters
- client_id: (optional) name of the client id
- connection(s):
- discovery_key: (optional) key to retrieve the connection from IDiscovery
- host: host name or IP address
- port: port number
- uri: resource URI or connection string with all parameters in it
- credential(s):
- store_key: (optional) key to retrieve the credentials from ICredentialStore
- username: username
- password: user’s password
- options:
- retry_connect: (optional) turns on/off automated reconnect when connection is log (default: true)
- connect_timeout: (optional) number of milliseconds to wait for connection (default: 30000)
- reconnect_timeout: (optional) number of milliseconds to wait on each reconnection attempt (default: 1000)
- keepalive_timeout: (optional) number of milliseconds to ping broker while inactive (default: 3000)
References
- *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
- *:counters:*:*:1.0 - (optional) ICounters components to pass collected measurements
- *:discovery:*:*:1.0 - (optional) IDiscovery services
- *:credential-store:*:*:1.0 (optional) credential stores to resolve credentials
Constructors
Creates a new instance of the connection component.
MqttConnection()
Fields
Instance methods
checkOpen
Checks if the connection is open.
Raises an error if the connection is closed.
void checkOpen()
close
Closes a component and frees used resources.
@override
Future close(IContext? context)
- context: IContext - (optional) a context to trace execution through a call chain.
configure
Configures the component by passing its configuration parameters.
@override
void configure(ConfigParams config)
- config: ConfigParams - configuration parameters to be set.
createQueue
Creates a message queue. If the connection doesn’t support this function, it exists without error.
@override
Future<void> createQueue(String name)
- name: String - name of the queue to be created.
deleteQueue
Deletes a message queue. If connection doesn’t support this function, it exists without error.
@override
Future<void> deleteQueue(String name)
- name: String - name of the queue to be deleted.
getConnection
Gets the connection.
mqtt.MqttServerClient? getConnection()
- returns: mqtt.MqttServerClient? - connection to a MySQL database
isOpen
Checks if the component is open.
@override
bool isOpen()
- returns: bool - true if the component is open and false otherwise.
open
Opens the component.
@override
Future open(IContext? context)
- context: IContext - (optional) a context to trace execution through a call chain.
publish
Publish a message to a specified topic.
Future publish(String topic, String data, Map<String, dynamic> options)
- topic: String - topic name
- data: String - message to be published
- options: Map<String, dynamic> - publishing options
readQueueNames
Reads a list of registered queue names. If the connection doesn’t support this function, it returns an empty list.
@override
Future<List<String>> readQueueNames()
- returns: Future<List<String>> - queue names.
setReferences
Sets references to dependent components.
@override
void setReferences(IReferences references)
- references: IReferences - references to locate the component dependencies.
subscribe
Subscribes to a topic
Future subscribe(String topic, Map<String, dynamic> options, IMqttMessageListener listener)
- topic: String - topic name
- options: Map<String, dynamic> - subscription options
- listener: IMqttMessageListener - message listener
unsubscribe
Unsubscribes from a previously subscribed topic.
Future unsubscribe(String topic, IMqttMessageListener listener)
- topic: String - topic name
- listener: IMqttMessageListener - message listener