MMM-FRITZ-Box-Callmonitor-py3 + MMM-Callmonitor-Current-Call Window

[wuermchen]

Hello
I’m running the modules MMM-FRITZ-Box-Callmonitor-py3 and MMM-Callmonitor-Current-Call. They work well. Unfortunately, there’s an occasional error.
The caller’s window gets stuck and the background remains grayed out. Can anyone help me?

[rkorell]

@wuermchen which fork are you using?
There was a newer implementation, I guess last year.
This version resolved the sticky caller-window (at least for me).

Good luck,
Regards,
Ralf

[wuermchen]

I’ve just reinstalled the new version of drtorchwood. Let’s see if the error occurs again.

[wuermchen]

The error is still there.
I think the error always occurs with spam calls. Is there a way to hide a specific phonebook?

[wuermchen]

This post is deleted!

[wuermchen]

Hello,
I am now certain that this issue is related to blocked phone numbers. I am using the following version:
https://github.com/xIExodusIx/MMM-FRITZ-Box-Callmonitor-py3

I attempted to modify node_helper.js to prevent these calls from being processed at all, but unfortunately, without success.

Since the FRITZ!Box sends the RING and DISCONNECT signals almost simultaneously for blocked numbers, the module triggers two notifications to the screen. The browser attempts to render two pop-ups at the same time and subsequently crashes.

Does anyone have an idea how to solve this problem?
I would greatly appreciate any input or suggestions.

[rkorell]

dear @wuermchen,

this should be a classic race condition and should be solvable in node_helper.js without much effort.

Background: The FRITZ!Box call monitor (port 1012) tags every event of a call with the same ConnectionId:

date;RING;<id>;<caller>;<callee>;...
date;DISCONNECT;<id>;<duration>;

For numbers blocked by the FRITZ!Box, RING and DISCONNECT arrive within a few milliseconds. The module currently fires the notification immediately
on RING — that’s why you end up with two overlapping pop-ups and the browser crashes.

Fix: Don’t propagate RING immediately. Buffer it briefly, and if a DISCONNECT for the same ConnectionId arrives within a short window, drop the
event entirely.

Rough sketch for node_helper.js:

const SUPPRESS_WINDOW_MS = 1500;
const pendingRings = new Map();   // connectionId -> timer

// on RING:
const timer = setTimeout(() => {
  pendingRings.delete(connectionId);
  this.sendSocketNotification("call", ringPayload);   // original notify
}, SUPPRESS_WINDOW_MS);
pendingRings.set(connectionId, timer);

// on DISCONNECT:
const timer = pendingRings.get(connectionId);
if (timer) {
  clearTimeout(timer);
  pendingRings.delete(connectionId);
  return;   // spam call suppressed, no notification at all
}
// otherwise: handle DISCONNECT as before

Why this works:

• Only suppresses calls that terminate almost instantly (FRITZ!Box block list, “do not disturb”)
• Regular missed calls (phone rings 10 s, nobody answers) still trigger the pop-up — just delayed by ~1.5 s, which is invisible in practice
• No second pop-up, no browser crash

Tuning: 1500 ms is a safe default. You can lower it to 500–800 ms if you want faster feedback, or expose it as a config option

suppressWindow: 1500,

Hope that helps.
Warmest regards,

Ralf

[rkorell]

Dear @wuermchen ,
as I read that you’ve already tried to solve this - may a more concrete description is useful for you:

Repo: https://github.com/xIExodusIx/MMM-FRITZ-Box-Callmonitor-py3
Patched file: node_helper.js (only this one file is changed)
Frontend file: unchanged

Problem

Numbers blocked via the FRITZ!Box “number range” blocklist (Rufnummern-Bereichsliste, not phonebook-blocked) cause the FRITZ!Box to emit RING and DISCONNECT events within a few milliseconds of each other.

The original module fires:

• SHOW_ALERT immediately on inbound
• HIDE_ALERT immediately on disconnected

Both DOM updates happen within the same render frame → browser crashes.

Phonebook-blocked numbers are handled separately (the library emits a dedicated blocked event) and are not affected by this issue.

---

Fix concept

Don’t fire SHOW_ALERT immediately. Buffer the inbound notification for SPAM_SUPPRESS_WINDOW_MS (default: 1500 ms). If a disconnected event for the same call.id arrives within that window → drop the call entirely. No SHOW_ALERT, no HIDE_ALERT, no DOM churn.

Real calls (ring duration > 1.5 s, or accepted within 1.5 s) work exactly as before — the only difference is the pop-up appears with a ~1.5 s delay, which is invisible in practice.

---

Behavior matrix

Scenario	Behavior
Real call, rings > 1.5 s	Pop-up appears with ~1.5 s delay (imperceptible)
Real call, accepted within 1.5 s	connected handler flushes the timer, fires CALL_CONNECTED
Spam call (RING + DISCONNECT < 1.5 s)	Timer is cancelled, no notification at all → no crash
Phonebook-blocked number	Unchanged — library emits dedicated blocked event
Outbound call	Unchanged — separate event path, Map is never touched

---

Changes (all in node_helper.js)

#	Location	Action
1	After line 11 (after require imports)	Add constant SPAM_SUPPRESS_WINDOW_MS = 1500
2	start: (line 23–29)	Add one line: this.pendingInbound = new Map();
3	monitor.on("inbound", ...) (line 82–87)	Replace body — instead of firing sendSocketNotification immediately, store a timer in the Map
4	monitor.on("connected", ...) (line 105–110)	Add timer-cleanup at the start, rest unchanged
5	monitor.on("disconnected", ...) (line 113–117)	Add timer-check at the start — if pending → clearTimeout + return

All changes are marked with // CHANGES for wuermchen comments in the file.

---

Tuning

SPAM_SUPPRESS_WINDOW_MS = 1500 is a safe default.

• Very fast hardware/network: 800–1000 ms is enough
• Slow setups: bump to 2000 ms
• For a runtime config option, expose it as this.config.suppressWindow and read in setupMonitor

---

Caveats / things to verify in your setup

1. call.id must exist on the library’s event objects.
   The library node-fritzbox-callmonitor derives it from the FRITZ!Box stream’s ConnectionId. Should work, but if your installed library version uses a different property name (e.g. call.connectionId), adjust accordingly. Easy to verify with console.log(call) in the inbound handler.

2. Assumption: blocklist-range calls emit inbound + disconnected.
   This matches the forum description (RING + DISCONNECT). If your specific FRITZ!Box firmware emits something different (e.g. directly blocked), the patch won’t help — but won’t break anything either, because the existing blocked path is untouched.

3. Side effect: no RELOAD_CALLS for suppressed spam calls.
   The original disconnected handler triggers a refresh of the call list from the FRITZ!Box API. Suppressed spam calls won’t trigger this refresh — the on-screen list updates only at the next real event. Acceptable in practice (spam calls are in the FRITZ!Box history anyway).

---

Installation

cd ~/MagicMirror/modules/MMM-FRITZ-Box-Callmonitor-py3
cp node_helper.js node_helper.js.orig           # backup
# replace node_helper.js with the patched version
touch ~/MagicMirror/config/config.js            # graceful restart via pm2 file-watch

Rollback:

cd ~/MagicMirror/modules/MMM-FRITZ-Box-Callmonitor-py3
cp node_helper.js.orig node_helper.js
touch ~/MagicMirror/config/config.js

---

Complexity assessment

Structurally simple — one file, one function (setupMonitor), ~15 new lines. No race conditions (Node.js is single-threaded). No memory leak (timer + Map entry are explicitly cleaned up in every code path).

The uncertainty is not in the code, but in the two library assumptions above (point 1 and 2 under Caveats). The fix has not been verified against a live spam call yet — it is derived from the forum description and the library’s documented event model.

complete patched node_helper.js:
(You will find all changes marked with “// CHANGES for wuermchen — Spam-Call Suppression”

"use strict";

const NodeHelper = require("node_helper");
const CallMonitor = require("node-fritzbox-callmonitor");
const vcard = require("vcard-json");
const phoneFormatter = require("phone-formatter");
const xml2js = require("xml2js");
const moment = require('moment');
const exec = require('child_process').exec;
const {PythonShell} = require('python-shell');
const path = require("path");

// ============================================================================
// CHANGES for wuermchen — Spam-Call Suppression
// ----------------------------------------------------------------------------
// Background: FRITZ!Box "number range" blocklist entries trigger RING and
// DISCONNECT almost simultaneously. The original code fires SHOW_ALERT on
// "inbound" and HIDE_ALERT on "disconnected" immediately, causing two
// overlapping DOM updates within a few ms → browser crashes.
//
// Fix: buffer "inbound" notifications for SPAM_SUPPRESS_WINDOW_MS. If a
// "disconnected" with the same call.id arrives before the timer fires, drop
// the call entirely (no SHOW_ALERT, no HIDE_ALERT). Real calls (ring > 1.5 s
// or accepted) work as before, just with ~1.5 s delay on the pop-up.
// ============================================================================
const SPAM_SUPPRESS_WINDOW_MS = 1500;
// ============================================================================

const CALL_TYPE = Object.freeze({
	INCOMING: "1",
	MISSED: "2",
	OUTGOING: "3",
	BLOCKED: "10"		//New entry for blocked calls as found on: https://fritzconnection.readthedocs.io/en/1.14.0/sources/library_modules.html
})
//outgoing missed calls are not in the list

module.exports = NodeHelper.create({
	// Subclass start method.
	start: function () {
		this.ownNumbers = []
		this.started = false;
		//create addressbook dictionary
		this.AddressBook = {};
		// CHANGES for wuermchen — pending inbound calls awaiting suppression decision
		this.pendingInbound = new Map();   // call.id -> timer
		console.log("Starting module: " + this.name);
	},

	normalizePhoneNumber(number) {
		return phoneFormatter.normalize(number.replace(/\s/g, ""));
	},

	getName: function (number) {
		//Normalize number
		var number_formatted = this.normalizePhoneNumber(number);
		//Check if number is in AdressBook if yes return the name
		if (number_formatted in this.AddressBook) {
			return this.AddressBook[number_formatted];
		} else {
			//Not in AdressBook return original number
			return number;
		}
	},

	socketNotificationReceived: function (notification, payload) {
		//Received config from client
		if (notification === "CONFIG") {
			//set config to config send by client
			this.config = payload;
			//if monitor has not been started before (makes sure it does not get started again if the web interface is reloaded)
			if (!this.started) {
				//set started to true, so it won't start again
				this.started = true;
				console.log("Received config for " + this.name);

				this.parseVcardFile();
				this.setupMonitor();
			}
			//send fresh data to front end (page might have been refreshed)
			if (this.config.password !== "") {
				this.loadDataFromAPI();
			}
		}
		if (notification === "RELOAD_CALLS") {
			this.loadDataFromAPI("--calls-only");
		}
		if (notification === "RELOAD_CONTACTS") {
			this.loadDataFromAPI("--contacts-only");
		}
	},

	setupMonitor: function () {
		//helper variable so that the module-this is available inside our callbacks
		var self = this;

		//Set up CallMonitor with config received from client
		var monitor = new CallMonitor(this.config.fritzIP, this.config.fritzPort);

		// ====================================================================
		// CHANGES for wuermchen — buffer inbound instead of firing immediately
		// ====================================================================
		monitor.on("inbound", function (call) {
			//If caller is not empty
			if (call.caller == "") return;
			var payload = self.getName(call.caller);
			var timer = setTimeout(function () {
				self.pendingInbound.delete(call.id);
				self.sendSocketNotification("call", payload);
			}, SPAM_SUPPRESS_WINDOW_MS);
			self.pendingInbound.set(call.id, timer);
		});
		// ====================================================================

		monitor.on("outbound", function (call) {
			//Save own number (call.caller) to ownNumbers Array to distinguish inbound/outbound on "connected" handler
			if (!self.ownNumbers.includes(call.caller))
				self.ownNumbers.push(call.caller)
				self.sendSocketNotification("outbound", call.called);

		});

		//Call blocked
		monitor.on("blocked", function (call) {
				var name = call.type === "blocked" ? self.getName(call.called) : self.getName(call.caller);
				//send clear command to interface
				self.sendSocketNotification("blocked", self.getName(call.caller)); //{ "caller": name, "duration": call.duration });
		});

		//Call accepted
		monitor.on("connected", function (call) {
			// CHANGES for wuermchen — flush pending inbound timer before firing connected
			var pending = self.pendingInbound.get(call.id);
			if (pending) {
				clearTimeout(pending);
				self.pendingInbound.delete(call.id);
			}
			var name = self.ownNumbers.includes(call.caller) ? self.getName(call.called) : self.getName(call.caller);
			var direction = self.ownNumbers.includes(call.caller) ? "out" : "in";
			self.sendSocketNotification("connected", { "caller": name, "direction": direction });

		});

		//Caller disconnected
		monitor.on("disconnected", function (call) {
			// CHANGES for wuermchen — if inbound was still buffered, this is a spam call: suppress both
			var pending = self.pendingInbound.get(call.id);
			if (pending) {
				clearTimeout(pending);
				self.pendingInbound.delete(call.id);
				return;   // never showed the pop-up, no need to clear it
			}
			var name = call.type === 'outbound' ? self.getName(call.called) : self.getName(call.caller);
			//send clear command to interface
			self.sendSocketNotification("disconnected", { "caller": name, "duration": call.duration });
		});
		console.log(this.name + " is waiting for incoming calls.");
	},

	parseVcardFile: function () {
		var self = this;

		if (!this.config.vCard) {
			return;
		}
		vcard.parseVcardFile(self.config.vCard, function (err, data) {
			//In case there is an error reading the vcard file
			if (err) {
				self.sendSocketNotification("error", "vcf_parse_error");
				if (self.config.debug) {
					console.log("[" + self.name + "] error while parsing vCard " + err);
				}
				return
			}

			//For each contact in vcf file
			for (var i = 0; i < data.length; i++) {
				//For each phone number in contact
				for (var a = 0; a < data[i].phone.length; a++) {
					//normalize and add to AddressBook
					self.AddressBook[self.normalizePhoneNumber(data[i].phone[a].value)] = data[i].fullname;
				}
			}
			self.sendSocketNotification("contacts_loaded", Object.keys(self.AddressBook).length);
		});
	},

	loadCallList: function (body) {
		var self = this;

		xml2js.parseString(body, function (err, result) {
			if (err) {
				self.sendSocketNotification("error", "calllist_parse_error");
				console.error(self.name + " error while parsing call list: " + err);
				return;
			}
			var callArray = result.root.Call;
			var callHistory = []

			for (var index in callArray) {
				var call = callArray[index];
				var type = call.Type[0];
				//Trying to handle blocked calls these lines 164-171 are new from "if to else" and it works!
				if  (name = type == CALL_TYPE.BLOCKED || type == CALL_TYPE.INCOMING ? self.getName(call.Caller[0]) : self.getName(call.Called[0]));
					var duration = call.Duration[0];
					if (type == CALL_TYPE.INCOMING && self.config.deviceFilter && self.config.deviceFilter.indexOf(call.Device[0]) > -1) {
						continue;
				}
				else
				//From here the original script is ongoing
				var name = type == CALL_TYPE.MISSED || type == CALL_TYPE.INCOMING ? self.getName(call.Caller[0]) : self.getName(call.Called[0]);
				var duration = call.Duration[0];
					if (type == CALL_TYPE.INCOMING && self.config.deviceFilter && self.config.deviceFilter.indexOf(call.Device[0]) > -1) {
						continue;
				}
				var callInfo = { "time": moment(call.Date[0], "DD.MM.YY HH:mm"), "caller": name, "type": type, "duration": duration };
				if (call.Name[0]) {
					callInfo.caller = call.Name[0];
				}
				callHistory.push(callInfo)
		}
			self.sendSocketNotification("call_history", callHistory);
		});
	},

	loadPhonebook: function (body) {
		var self = this;

		xml2js.parseString(body, function (err, result) {
			if (err) {
				self.sendSocketNotification("error", "phonebook_parse_error");
				if (self.config.debug) {
					console.error(self.name + " error while parsing phonebook: " + err);
				}
				return;
			}
			var contactsArray = result.phonebooks.phonebook[0].contact;
			for (var index in contactsArray) {
				var contact = contactsArray[index];
				var contactNumbers = contact.telephony[0].number;
				var contactName = contact.person[0].realName;

				for (var index in contactNumbers) {
					var currentNumber = self.normalizePhoneNumber(contactNumbers[index]._);
					self.AddressBook[currentNumber] = contactName[0];
				}
			}
			self.sendSocketNotification("contacts_loaded", Object.keys(self.AddressBook).length);
		});
	},

	loadDataFromAPI: function (additionalOption) {
		var self = this;

		if (self.config.debug) {
			console.log('Starting access to FRITZ!Box...');
		}

		let args = ['-i', self.config.fritzIP, '-p', self.config.password];
		if (self.config.username !== "") {
			args.push('-u');
			args.push(self.config.username);
		}
		if (additionalOption) {
			args.push(additionalOption);
		}

		let options = {
			pythonPath: 'python3',
			mode: 'json',
			scriptPath: path.resolve(__dirname),
			args: args
		};

		let pyshell = new PythonShell('fritz_access.py', options);

		pyshell.on('message', function (message) {
			if (message.filename.indexOf("calls") !== -1) {
				//Call list file
				self.loadCallList(message.content);
			} else {
				//Phone book file
				self.loadPhonebook(message.content);
			}
		});

		//End the input stream and allow the process to exit
		pyshell.end(function (error) {
			if (error) {
				var errorUnknown = true;
				if (error.traceback.indexOf("XMLSyntaxError") !== -1) {
					//Password is probably wrong
					self.sendSocketNotification("error", "login_error");
					errorUnknown = false;
				}
				if (error.traceback.indexOf("failed to load external entity") !== -1) {
					//Probably no network connection
					self.sendSocketNotification("error", "network_error");
					errorUnknown = false;
				}
				if (errorUnknown) {
					self.sendSocketNotification("error", "unknown_error");
				}
				if (self.config.debug) {
					console.error(self.name + " error while accessing FRITZ!Box: ");
					console.error(error.traceback);
				}
				return;
			}
			if (self.config.debug) {
				console.log('Access to FRITZ!Box finished.');
			}
		});
	}
});

[wuermchen]

@Thank you very much for your great help. I tried out your new node_helper.js file. Unfortunately, it still didn’t work.
I continued working with your changes and discovered the issue: I am running the very latest version of Node.js (v24). However, the node-fritzbox-callmonitor module is ancient. In the background, it utilizes a network interface that—in modern Node versions—sometimes listens to thin air if the IP family (IPv4 vs. IPv6) is not explicitly specified. It ends up silently connecting to the Fritz!Box’s IPv6 address while the incoming signal arrives via IPv4—meaning it completely misses the call notification.
Additionally, I changed the IP address in the configuration file from 192.168.1.1 to fritz.box. It seems to be working now; my blocked number is no longer being displayed. I will continue to monitor the situation and provide feedback if anything changes. Thank you very much for your work.

[rkorell]

Dear @wuermchen - you’re welcome.

Great that you’ve identified some additional issues and now have a working solution!
Congratulations!

Warm regards,
Ralf