hubs_presence.js

var ui = document.querySelector("[title=Members]")
// requires the presence menu to be open (because React) but could be hidden via CSS
if ( !ui.className.match("selected") ) {
  ui.dispatchEvent(new MouseEvent("click",{bubbles: true, cancellable: true}))
}
//ui.nextSibling.style.display = "none" // hides UI if you are streaming

previousMeasures = JSON.parse( localStorage.getItem('hubs-measurements') );
if (!previousMeasures) previousMeasures = []

//clearInterval(measuring)
let measuring = setInterval(addMeasure, 60*1000 )

function addMeasure(){
  let moment = Date.now()
  let connected = []

  for (let r of document.querySelectorAll("[class^=presence-list__row__]")){    
    let nick = hashCode( r.querySelector("[class*=item__]").innerText.replace("★","") )
    let presence = r.querySelector("[class*=presence__]").innerText
    connected.push( {hash:nick, presence:presence} )
  }

  // ignored as it is only for persons in the room
  // for (let a of document.querySelectorAll("[networked-avatar]"))
  //   connected.push( a.getAttribute("networked").networkId )
  
  previousMeasures.push( {now:moment, connected:connected} )
  localStorage.setItem('hubs-measurements', JSON.stringify(previousMeasures));
  // Alternatively the data could be posted periodically to a micro-service
  // then allowing live analytics e.g. https://observablehq.com/@utopiah/mozilla-hubs-event-stats
}

// to log chat see also https://gist.github.com/Utopiah/44d38c33dc9ab38f123530e4db1c49b8

const hashCode = s => s.split('').reduce((a,b) => (((a << 5) - a) + b.charCodeAt(0))|0, 0)
// via https://stackoverflow.com/a/34842797