Head first developing MM module for extreme beginners

A Former User

I cant get the text to appear when I run it, I made the Test.js file in the MagicMirror modules folder and copied in what was posted and put the config in the config.js file but when I run it the screens all black, here’s what happens when I try to run it

pi@raspberrypi:~/MagicMirror/modules $ cd ~/MagicMirror
pi@raspberrypi:~/MagicMirror $ npm start dev

magicmirror@2.8.0 start /home/pi/MagicMirror
sh run-start.sh “dev”

Starting MagicMirror: v2.8.0
Loading config …
Loading module helpers …
No helper found for module: MMM-Test.
All module helpers loaded.
Starting server on port 8080 …
Server started …
Sockets connected & modules started …
Launching application.
Shutting down server…
pi@raspberrypi:~/MagicMirror $

any help would be greatly appreciated I dont see what I’m missing

StuGrunt

It is because there is an error (at least I think so - I am new too) and no instructions on where to put the function.

change the Module.register(“MMM-Timetable”) to Module.register(“MMM-Test”)
The article does not tell you where to put the getDom function when it is first introduced. Replace the getDom: function() {}. with the code shown. In other words, don’t just add it to the file. This article would have benefited from a final section that gave the entire code.

I think the original author at least expected us to be very familiar with Node.js (fair enough), but alas, I am not so it took a bit of work to figure it out. :-)

Here it is, for the first part:

Module.register(“MMM-Test”, {
defaults: {},
start: function () {},

getDom: function() {
var element = document.createElement(“div”)
element.className = “myContent”
element.innerHTML = “Hello, World!”
return element
},
notificationReceived: function() {},
socketNotificationReceived: function() {},
})
_

nrayever

Shame, code is really messed up. Not helpful to use it as a guide to start developing modules.

sdetweil

@nrayever see my sample module,
https://github.com/sdetweil/SampleModule

and follow the module developers doc

nrayever

@sdetweil will try it. I don’t have JS experience that is why I have found it difficult to start.

sdetweil

@nrayever sorry cant help develop module if u dont know programming and dont want to learn

cowboysdude

@StuGrunt said in Head first developing MM module for extreme beginners:

It is because there is an error (at least I think so - I am new too) and no instructions on where to put the function.

change the Module.register(“MMM-Timetable”) to Module.register(“MMM-Test”)

The article does not tell you where to put the getDom function when it is first introduced. Replace the getDom: function() {}. with the code shown. In other words, don’t just add it to the file. This article would have benefited from a final section that gave the entire code.

I think the original author at least expected us to be very familiar with Node.js (fair enough), but alas, I am not so it took a bit of work to figure it out. :-)

Here it is, for the first part:

Module.register(“MMM-Test”, {
defaults: {},
start: function () {},

getDom: function() {
var element = document.createElement(“div”)
element.className = “myContent”
element.innerHTML = “Hello, World!”
return element
},
notificationReceived: function() {},
socketNotificationReceived: function() {},
})
_

Both of those functions go outside the getDom function pretty much anywhere you want to put them.

The socketNotificationReceived function [example below, can be used in either node_helper OR your main.js file. The example below is in my node_helper] :

socketNotificationReceived: function(notification, payload) {
		if (notification === 'CONFIG') {
            this.config = payload; 
        }
        if (notification === 'GET_CURRENT') {
            this.getCurrent(payload);
        }
        if (notification === 'GET_FORECAST') {
            if (this.forecast.timestamp === this.getDate() && this.forecast.data !== null) {
                this.sendSocketNotification('FORECAST_RESULT', this.forecast.data); 
                console.log("Using data we already have");
            } else { 
                this.getForecast();
				console.log("Getting new data");
            }
        }
		
    }

Here is the corresponding one in the main.js

socketNotificationReceived: function(notification, payload) {
        if (notification === "CURRENT_RESULT") {
            this.processCurrent(payload);
        }
        if (notification === "FORECAST_RESULT") {
            this.processForecasts(payload);
        }
		this.updateDom(this.config.initialLoadDelay);
    },

You can use notificationReceived to receive info from other modules like this:

Here are examples of that:

notificationReceived: function (notification, payload){ 
        if (notification === 'CURRENT_RESULT') {
			this.processCurrent(payload); 
        }
	},

this.sendNotification('CURRENT_RESULT', payload);

This is how I send and receive my ‘payload’ from one module to another.
The first example is getting my ‘CURRENT_RESULT’ [getting info for a Forecast module from the Current weather module] from the bottom example that is
sending out ‘CURRENT_RESULT’…

The bottom example will ‘broadcast’ and in reality ANY module can get the data it’s sending out.

Hope this helps. It’s a really simple process.

Schmaniel

How can I test the getDom() html output?
I don’t want to restart MM every time when I change something just to look if it worked.

sdetweil

@Schmaniel ctrl-r to reload the screen

nrayever

@sdetweil … ok.

Dobi

Hey guys,

I’m quite new in developing an own module. I was able to change exiting modules on my magic mirror but now I wanted to create my own module, but I’m not able to get socket communication between my “main” module an the “helper-function”

I uploaded my module here:
https://github.com/Dobherrmann/MMM_Testmodul.git
my Module looks like this on my magic mirror:

maybe someone can find my mistake(s).

BR

sdetweil

@dobi two things

when the DomObject Created method is called, its POSSIBLE that the elements are not yet accessible… so your code fails as the document.getElementbyID returns null…

second, do you have a position: set in the module def in config.js?

third and MOST important

the module NAME must match the folder name AND the filename and the register in the file…

so, the filename is MMM-cookbook.js
therefore ALL the things must be called MMM-cookbook

git clone will name the folder the name of the github repo
(unless u add an extra part to git clone repo_url output_folder_name)

I fixed all those and the module displays the countdown/up each second

Dobi

@sdetweil ahh thank you for these information I will give it a try.

Dobi

@sdetweil I gave it a try but without differences :(
I made a new git repo : https://github.com/Dobherrmann/MMM-cookbook.git
Now there I should have the same name in the repo like my module.

my config. js looks like this (I gave it a position):

 {
      module: "MMM-cookbook",
      position: "middle_center",
      config: {
        header: "My Cookbook",
        foo: "I'm the King of the world!"
      }
    },

I started to debug “my code” a little bit and I found this when I want to send a socket notification:

self.sendSocketNotification("DO_YOUR_JOB", this.count);
					console.log("Notfication", this.sendSocketNotification("DO_YOUR_JOB", this.count))
					this.sendSocketNotification("DO_YOUR_JOB", this.count)
					this.subElementUp.innerHTML = "Count UP:" + this.count

On my console i get the feedback that “this.sendSocketNotification(“DO_YOUR_JOB”, this.count” is undefined. It looks like that this function is unkown.

sdetweil

@dobi u are inside a callback. change the ‘this’ to ‘self’ like the self.sendSocketNotification

‘this’ is always tricky. depends on the context, and some of the programming idioms used

that’s why we typically see
var self = this;
at the beginning of functions that have callbacks or .then() used inside

Dobi

@sdetweil ok, but it dosen’t change something.

notificationReceived: function (notification, payload, sender) {
		self = this;
		switch (notification) {
			case "DOM_OBJECTS_CREATED":
				var timer = setInterval(() => {
					//this.updateDom()
					self.sendSocketNotification("DO_YOUR_JOB", this.count);
					console.log(`self.sendSocketNotification("DO_YOUR_JOB", this.count)`, self.sendSocketNotification("DO_YOUR_JOB", this.count))
					self.sendSocketNotification("DO_YOUR_JOB", this.count)
					this.subElementUp.innerHTML = "Count UP:" + this.count
					this.count++
				}, 1000)
				break
		}
	},

Now i could post a picture of my console

sdetweil

@dobi show the source code page. u had to fix both counters

sources tab, modules, mmm-cookbook, mmm-cookbook.js

sdetweil

@dobi

self.sendSocketNotification("DO_YOUR_JOB", this.count)

but u didn’t change this.count to self.count
in all the places

Dobi

@sdetweil I replaced all this. … calls to self. … but I don’t get a change. Is there a way that I can check to check that I can check that the function is loaded correctly from the kernal?

sdetweil

@dobi view the source in the dev window

what u showed above is not changed