1. getDom() shall take care of all the drawing. in .getDom() put all of your rendering framework and contents. and you can refresh your render by calling .updateDom()

2. getDom() shall draw only framework, Contents should be drawn by your another function with HTML DOM manipulation.

3. or getDom() just return empty wrapper, Then, all of your rendering and refreshing will be performed by yourself.

Which is better? case-by-case.

For the last question; I cannot figure out. :)

just one problem i need to give a position in config. i think i have miss something

Module.register("MMM-keylogger",{
	defaults: {
		 updateInterval:  1500,
	},

	notificationReceived: function(noti, payload, sender) {
		Log.log(`notif : ${noti}`);
		switch(noti) {
		  case 'MODULE_DOM_CREATED':
			this.initMyDOM()
			break
		}
	  },
	  initMyDOM: function() {
		var wrapper = document.createElement("div")
		wrapper.id = "myDOM"
		var container = document.body
		container.appendChild(wrapper)
		Log.log(`init DOM `);
		var timer = setInterval(()=>{
			var d = document.getElementById("myDOM")
			d.innerHTML =  this.dataFile
		Log.log(`key : ${d.innerHTML} , ${this.dataFile} `);
			if(d.innerHTML){
				switch(d.innerHTML) {
					case "Right":
					this.sendNotification("PAGE_INCREMENT");
						break;
					case "Left" :
					this.sendNotification("PAGE_DECREMENT");
						break;
					default:
					Log.log(`key : ${d.innerHTML} pressed but not assigned`);
				}
				this.sendSocketNotification("Clear_key")
			}
			
			}, 1500)
	},

	start: function(){
        console.log(this.name + " has started...!!!!!!");
		this.sendSocketNotification("START", this.config);
	},

	socketNotificationReceived: function(notification, payload) {
		if(notification === "KEY_P"){
			this.dataFile = payload;
			// this.updateDom();
        }
	},

if i don’t give position on config its don’t work ! if i have understand what you have say. this is suppose to work

other question : one of my other module have subitly stop to work and make same error but in this module in need position and update with Miror display. so my question is : this is possible this modification have impact on other module ?

1. use .getDom() with proper position
2. or, not using .getDom().

• You can start to manipulate your DOM when DOM_OBJECTS_CREATED notification from MM Core.
  like these;

notificationReceived: function(noti, payload, sender) {
  switch(noti) {
    case 'DOM_OBJECTS_CREATED':
      this.initMyDOM()
      break
  }
},
initMyDOM: function() {
  var wrapper = document.createElement("div")
  wrapper.id = "myDOM"
  var container = document.body
  container.appendChild(wrapper)
  
 var timer = setInterval(()=>{
  var d = document.getElementById("myDOM")
  d.innerHTML = "This is rendered without getDom and position"
  }, 1000)
}

This is not tested on real device, but you can catch the idea.

have you an idea for appendChild error ?

thanks you have suppress the first error on screen-shot
but my modul write something on screen and i don’t want that but its can be cool for debug

if i remove my module i have one error (i correct after if i can)

but the looping are ok

my module

Module.register("MMM-keylogger",{
	curentPage: -1,
	defaults: {
		updateInterval:  1000,
	},

	start: function(){
        console.log(this.name + " has started...!!!!!!");
		this.sendSocketNotification("START", this.config);
	},

	socketNotificationReceived: function(notification, payload) {
		if(notification === "KEY_P"){
			this.dataFile = payload;
			this.updateDom();
        }
	},

	getDom: function(){
		var wrapper = document.createElement("div");
		wrapper.innerHTML = this.dataFile
			if(this.dataFile){
				switch(wrapper.innerHTML) {
					case "Right":
					this.sendNotification("PAGE_INCREMENT");
						break;
					case "Left" :
					this.sendNotification("PAGE_DECREMENT");
						break;
					default:
					Log.log(`key : ${wrapper.innerHTML} pressed but not assigned`);
				}
				this.sendSocketNotification("Clear_key")
			}
			return wrapper;
	},

});

const NodeHelper = require("node_helper");
const fs= require("fs");

module.exports = NodeHelper.create({
//here comes the part of the nodehelper after the 3 dots as posted above

	socketNotificationReceived: function(notification, payload) {
		if(notification === "START"){
			this.config = payload;
			this.readData();
    			setInterval(() => {
        			this.readData();
    			}, this.config.updateInterval);
		}
		if(notification === "Clear_key")
		{
			fs.open('Key_pres.txt', 'r+', function(err, fd) {
				if (err) {
				   return console.error(err);
				}
				fs.ftruncate(fd, function(err){
					if (err){
					   console.log(err);
					}
					console.log("supose to trucate");
				})
			});
	}
	},

	readData: function(){
		fs.readFile("Key_pres.txt", "utf8", (err, data) => {
			if (err) throw err;
		   this.sendSocketNotification("KEY_P", data);
   })		
	}
});

i have no warning of no declare class or something like that on VS

sorry but i beginner with organisation of MM

thanks for your rapidity :)

1st says there’s no element by the class name you’re searching for. Either it’s not there or you’re looking in the wrong place.

2nd says you’re trying to append something that is not an element. You can’t append a string, for example.

For example, that’s a string and won’t work:

let parent = document.getElementById("parent");
let element = "<div>lorem ipsum</div>";
parent.appendChild(element);

This will work:

let parent = document.getElementById("parent");
let element = document.createElement("div");
element.innerHTML = "lorem ipsum";
parent.appendChild(element);