Abstract

Creates Mqtt message handler , receives , checks , transforms and foreward messages It supports the callbacks 'send' and 'publish'

Creates Mqtt message handler , receives , checks , transforms and foreward messages It supports the callbacks 'send' and 'publish'

Contents

• Meta
• Type definitions
• Class Mqtt
  • Parameters
  • Methods
    • _publishLogMessage
    • getConnections
    • on
    • processRequest
    • processSendMessage
    • restoreFromFile

Meta

| | | | --- | --- | | File | checkdefinitions.js | | Abstract | Creates Mqtt message handler , receives , checks , transforms and foreward messages It supports the callbacks 'send' and 'publish' | | 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 . |

| | | | --- | --- | | File | mqtt.js | | Abstract | Creates Mqtt message handler , receives , checks , transforms and foreward messages It supports the callbacks 'send' and 'publish' | | 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 . |

Type definitions

httpReturn {Object}

Object containing all information to create a http return information | Name | Type | Description | | ---- | ---- | ------- | | headers | Object | header parameters | | | payload | Object | payload data | | | statusCode | number | | |

Callback definitions

sendCallback

sendCallback Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | host | string | host name | | | port | number, string | number | | | path | string | http path for sending data | | | payload | Object | payload ( body ) to send | | | headers | Object | headers to send | |

publishCallback

publishCallback Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | message | Message | message published | |

Class Mqtt

new Mqtt(configuration)

Creates Mqtt message handler . It supports the callbacks 'send' and 'publish'

Mqtt Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | configuration | Object | configuration options for the instance | |

configuration properties

| Name | Type | Description | | ---------- | ------------ | ----------------- | | log | Object | logging options | | | fileName | string | filename for persistence | | | directory | string | directory ( file path ) for persistence | | | replyTimeoutInMilliseconds | number | timeout to wait for an answer of a http call , default 10 seconds | | | inFlightWindow | number | amount of qos 1 and qos 2 messages send for the same topic at the same time , default 1 | | | pubrelTimeoutInMilliseconds | number | timout to wait for a corresponding pubrel message , default one day | | | maxRetryCount | number | amount of resend of messages before forcing a disconnect | | | maxQueuSize | number | maximal amount of entries in a message queue | |

Mqtt Methods

_publishLogMessage

_publishLogMessage (service, value, clientId)

Publishes a log - message

_publishLogMessage Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | service | string | name of the service bringing the message | | | value | string | value of the log message | | | clientId | string | name of the client involved | |

getConnections

getConnections (clientId) => {httpReturn}

Gets all connections or a single connection ( depends on path )

getConnections Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | clientId | string | id of the client or "" | |

getConnections returns

| Type | Description | | ---- | ----------- | | httpReturn | http return information |

on

on (event, callback)

Sets a callback .

on Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | event | 'send', 'publish' | callback name | | | callback | sendCallback, publishCallback | the callback for send and publish | |

on throws

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

processRequest

processRequest (controls, payload, headers) => {httpReturn}

Calls a connection interface

processRequest Parameters

| Name | Type | Description | | ---------- | ------------ | ----------------- | | controls | string | name of the mqtt controls to call ( connect , disconnect , . . . ) | | | payload | Object | parameters for the interface ( see interfaces ) | | | headers | Object | headers of the http message | |

processRequest returns

| Type | Description | | ---- | ----------- | | httpReturn | http return information |

processSendMessage

async processSendMessage () => {number}

Processes all messages to send and for each message calls the provided callback functions registered by calls to 'on' : 'send' ( host , port , action , payload , headers )

processSendMessage returns

| Type | Description | | ---- | ----------- | | number | amount of messages sent |

restoreFromFile

restoreFromFile ()

Restores the broker state from a file