Abstract

Provides functions to connect to the ( http based ) yaha mqtt broker

Contents

• Meta
• Class Connect
  • Parameters
  • Members
  • Methods
    • close
    • connect
    • connectAndSubscribe
    • disconnect
    • on
    • pingreq
    • subscribe
    • unsubscribe

Meta

| | | | --- | --- | | File | connect.js | | Abstract | Provides functions to connect to the ( http based ) yaha mqtt broker | | Author | Volker Böhm | | Copyright | Copyright ( c ) 2020 Volker Böhm | | License | This software is licensed under the GNU LESSER GENERAL PUBLIC LICENSE Version 3 . It is furnished "as is" , without any support , and with no warranty , express or implied , as to its usefulness for any purpose . |

Class Connect

new Connect(clientId, brokerHost, brokerPort, listenerPort)

Organises connections to broker This is part of the http based mqtt broker . Use this class to connect/disconnect and subscribe/unsubscribe to the broker All functions are based on async/promises

Example

let connect = new Connect("/connect/test", "127.0.0.1", 9001, 9002);
result = await connect.connect(CLEAN);

Connect Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | clientId | string | id of this client | | | brokerHost | string | hostname ( or ip ) of the broker | | | brokerPort | number | port of the broker | | | listenerPort | number | port to listen for published messages from broker | |

Connect Members

| Name | Type | description | | ------------ | ------------ | ------------ | | isConnected | boolean | True , if the client is connected | | token | Object.<send:string, receive:string> | Gets/Sets send and receive token |

Connect Methods

close

async close ()

Closes the connection to the broker

connect

async connect (clean, version, keepAlive) => {Object}

Connects to the broker

connect Parameters

| Name | Type | Attribute | Default | Description | | ---------- | ------------ | ------------ | ------------ | ----------------- | | clean | boolean | | | true , if a disconnect shall clean any connection information | | | version | string | optional | '1 . 0' | interface version ( 0 . 0 or 1 . 0 ) | | | keepAlive | number | optional | 600000 | time in milliseconds the broker will keep the connection without receiving calls | |

connect returns

| Type | Description | | ---- | ----------- | | Object | payload returned from connect request |

connectAndSubscribe

async connectAndSubscribe (clean, topics, version, keepAlive) => {Object}

First connect , then subscribe

connectAndSubscribe Parameters

| Name | Type | Attribute | Default | Description | | ---------- | ------------ | ------------ | ------------ | ----------------- | | clean | boolean | | | true , if a disconnect shall clean any connection information | | | topics | Object | | | topics to subscribe to { topic1 : QoS1 , topic2 : QoS2 , . . . } | | | version | string | optional | '1 . 0' | interface version ( 0 . 0 or 1 . 0 ) | | | keepAlive | number | optional | 600000 | time in milliseconds the broker will keep the connection without receiving calls | |

connectAndSubscribe returns

| Type | Description | | ---- | ----------- | | Object | combined result from connect and subscribe |

disconnect

async disconnect (version) => {Object}

Disconnects from the broker

disconnect Parameters

| Name | Type | Attribute | Default | Description | | ---------- | ------------ | ------------ | ------------ | ----------------- | | version | string | optional | '1 . 0' | interface version ( 0 . 0 or 1 . 0 ) | |

disconnect returns

| Type | Description | | ---- | ----------- | | Object | empty object |

on

on (event, callback)

Sets a callback .

on Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | event | string | event name ( not case sensitive ) for the callback | | | callback | function | ( parameter ) | |

on throws

| Type | Description | | ---- | ----------- | | Error | if the event is not supported | | Error | if the callback is not 'function' |

pingreq

async pingreq () => {boolean}

Sends a ping request to signal the client is alive

pingreq returns

| Type | Description | | ---- | ----------- | | boolean | true on success |

subscribe

async subscribe (topics, version) => {Object}

Subscribe to the broker

subscribe Parameters

| Name | Type | Attribute | Default | Description | | ---------- | ------------ | ------------ | ------------ | ----------------- | | topics | Object | | | topics to subscribe to { topic1 : QoS1 , topic2 : QoS2 , . . . } | | | version | string | optional | '1 . 0' | interface version ( 0 . 0 or 1 . 0 ) | |

subscribe returns

| Type | Description | | ---- | ----------- | | Object | payload returned from subscribe request |

unsubscribe

async unsubscribe (topics, version) => {Object}

Unsubscribes from the broker

unsubscribe Parameters

| Name | Type | Attribute | Default | Description | | ---------- | ------------ | ------------ | ------------ | ----------------- | | topics | Array | | | topics to unsubscribe [ topic1 , topic2 , . . . ] | | | version | string | optional | '1 . 0' | interface version ( 0 . 0 or 1 . 0 ) | |

unsubscribe returns

| Type | Description | | ---- | ----------- | | Object | empty object |