Heos Stream

Node.js streams for HEOS protocol communication over a socket

HeosStream

Constructor

Construct an instance with a Socket obtainable via net.createConnection() or new net.Socket()

const {HeosStream} = require ('@sovpro/heos-stream')
const heos_stream = new HeosStream (socket)

Writing

Writing requires objects implementing a commmand object interface.

Command object interface

The comand interface is an object with a string command and object params property. command represents the host and pathname of a HEOS command url*.

const command_object = {
  command: 'string' ,
  params: {
    key: value ,
    // , key2: value 
    // , ...
  } 
}
heos_stream.write (command_object)

The key value pairs correspond to query string parameters that are appended to the HEOS command.

* host and pathname are the command group and command according to the specification.

Reading

Reading provides data objects that are one of:

• HeosData
• HeosResult
• HeosEvent

HeosData

All data provided by HeosStream is a HeosData instance consisting of a message and command property. A HeosResult or HeosEvent is provided if the data is determined to a be a result or an event.

Properties:

• message : A key value object
• command : The command that caused this data

HeosResult

HeosResult represents data that is known to be a command result.

Properties accompanying those from HeosData

• result : A string that is either 'success' or 'fail'
• payload : May be undefined, object or an array
• options : May be undefined or an array

HeosEvent

HeosEvent represents data that is known to be a HEOS event.

Properties accompanying those from HeosData

• event : A string name of the event (excluding 'event/' prefix)

Filtered Streams

There are two streams emitting data filtered to results (HeosResult) or events (HeosEvent).

HeosResultStream

An opt-in filtered stream that emits result (HeosResult) data with a command matching on of those provided to the constructor.

const result_stream = new HeosResultStream ([
  'player/set_volume'  ,
  'player/set_mute'    ,
  'player/toggle_mute' , 
  // ...
])
heos_stream.pipe (result_stream)
result_stream.on ('data', result_data => {
  // result_data.command will be one of
  // the commands provided to the constructor
  const {command, message} = result_data
})

HeosEventStream

An opt-in filtered stream that emits event (HeosEvent) data with a name matching one of those provided to the constructor.

const event_stream = new HeosEventStream ([
  'player_volume_changed'  ,
  // ...
])
heos_stream.pipe (event_stream)
event_stream.on ('data', event_data => {
  // event_data.event will be one of
  // the events provided the constructor
  const {event} = event_data
})

Links

• HEOS by Denon
• HEOS CLI Protocol Specification

Notice

This unsponsored software is provided, subject to a MIT license, unofficially and independently of Sound United, LLC, its affiliates, subsidiaries and brands (such as HEOS, Denon and any such not listed here).