Magicmirror: this.sendSocketNotification is not a function

[SamLewis0602]

I have just about finished my Traffic module to get current commute time, but I'm having difficulty sending a socket notification other than the initial one in my start function. The project can be found here and the issue lies in MMM-Traffic.js.

I send a socket notification in start which queries the google maps api in node_helper.js then sends a socket notification back to MMM-Traffic.js which will then call updateDom(). I'm using updateCommute() as a proxy for setInterval that will send the initial socket notification at the user defined interval, but I am getting an error saying that this.sendSocketNotification is not a function. Any ideas?

[paviro]

Really interested in your module! I am not sure (I am glad my Wunderlist module works at all). I think it has something to do with the setInterval(this.updateCommute, this.config.interval * 1000);. Have a look at my Wunderlist node_helper.js I had to pass this into the function called by setInterval in order for it to work.
In my code self == this at the point where the timer is executed.

My timer:
setInterval(self.updateData, self.config.interval, data, self, i);

My function:

updateData: function (data, self, i) {
    self.get_tasks(data[self.config.lists[i].replace(/\s+/g, '')].id, self.config.lists[i], function (data, list_id, list_name) {

      self.sendSocketNotification('WUNDERLIST_TASKS', {list_id: list_id, tasks: data, list_name: list_name});

     })
  },

[MichMich]

On my phone, so not a well formatted reply. The reason of your issue is that within the setTimout closure, this no longer points to your module instance. This is a common thing in JavaScript. To solve this, create a helper variable before your create the timer:

var self = this;

And then in the timer closure use:

self.sendSocketNotificaction(......

[paviro]

Would this be the timer inside of the setTimout closure?

[MichMich]

I think so, yes.

You can easily find out by logging this.

Log.log(this);

[MichMich]

And just to be clear. You can of course use any helper variable name. I prefer 'self' because I do a lot of Swift programming. But a lot of people use 'var that=this;' in JavaScript.

[SamLewis0602]

Many thanks to both of you! This is my first time using Node so I used your Wunderlist module frequently as a reference (and as a starting point). I just tried adding this as a parameter to the function and I'm no longer getting the original error, but the notification doesn't seem to be making it's way back to MMM-Traffic.js. Is there a way to log/see information inside of node_helper?

[paviro]

Use console.log(), output will appear in the terminal session you started the mirror in. Never thought that module would be used as reference :D Still hoping for someone with actually JavaScript knowledge to improve it a bit..

[MichMich]

The Log.log helper does not work in the node helper as you might have noticed. :)

console.log(aVariable);

Should work.

Note: to send a notification from the node helper to the front end, the frontend first needs to send a message (to open the connection.)

[MichMich]

Check this module for simple socket messages: https://github.com/MichMich/mmm-systemtemperature

[SamLewis0602]

Probably should have thought to just try the default console.log() :P
I send the first notification from front end to node helper each time so that shouldn't be an issue, but it doesn't seem like the notification is ever reaching the node helper except for the initial one sent in start.

[SamLewis0602]

Scratch that, it is reaching node_helper. So the issue must be somewhere in there. I'll keep looking.

[SamLewis0602]

Double scratch that, only the first one is reaching node helper. Losing my mind over here :P

[MichMich]

Can you post your code somewhere? So I can take a quick look? (Still on my phone, so I can only point you in the right direction.)

[SamLewis0602]

It is here: https://github.com/SamLewis0602/MMM-Traffic

[MichMich]

Ah, the way you use it, you shouldn't use self. (Only within a closure this is nessecery)

So only the sendSocketNotification in start is correctly fired. The others probably generate an error. Check your web inspector console.

[MichMich]

(I'd really love to explain it better. But typing on a phone is a b*tch)

[paviro]

Works in my module that way :/ At least I am doing the same thing in the Node helper script.

[SamLewis0602]

I almost wish they were generating errors because then I'd have a place to look, but I'm not getting any errors on the console. I'm confused why it works in start but not in updateCommute because it's the same line of code that sends the socketNotification.

[SamLewis0602]

Well not the exact same line but a duplicate.

[MichMich]

Also, the way you are currently building it, you can only use the module once. If you want to show two routes by adding the module to your config twice with a different destination, you're gonna have a bad time. ;)

[MichMich]

No, on one spot u use self. In start u use this. In this case: use this.
Also add some logging to see if your method is being called.

[SamLewis0602]

Right but self is just a proxy for this that I could pass to the function right?

[SamLewis0602]

The method in the interval is being called, and I logged self.url to make sure that passing this as self was functioning correctly.

[MichMich]

On the place where you use self, self does not exist. It only exists in start.

[MichMich]

Hmmm that's weird.

[SamLewis0602]

I passed self as a parameter at the end of the setIntervall call.

[MichMich]

You are making it unnecessary difficult. Try this:

updateCommute: function() {

    this.sendSocketNotification('TRAFFIC_URL', this.url);
},

[SamLewis0602]

That's what I had originally, and that's when I got the this.sendSocketNotification is not a function error.

[SamLewis0602]

Which left me very confused after an hour of digging, hence my post here :)

[MichMich]

Ok ... you did it: you got me out of bed! ;)
One second. Will look into it,

[paviro]

👍 👍 👍 Made my day :D

[SamLewis0602]

Oh man I'm sorry about that! I really appreciate the help, I'm currently a CS student at a university in the US so this has been a fun learning experience for me :)

[MichMich]

Ok, weird stuff: if you remove the this.sendSocketNotification('TRAFFIC_URL', this.url); from the start method, the notifications sent in the updateCommute will arrive. :-/

[SamLewis0602]

Interesting. I'll try calling updateCommute instead of sending it directly from start.

[MichMich]

So, this is what it should look like:

    start: function() {
        Log.info('Starting module: ' + this.name);
        this.loaded = false;
        this.url = 'https://maps.googleapis.com/maps/api/directions/json' + this.getParams();
        this.symbols = {
            'driving': 'fa fa-car',
            'walking': 'fa fa-odnoklassniki',
            'bicycling': 'fa fa-bicycle',
            'transit': 'fa fa-train'
        };

        setInterval(this.updateCommute, this.config.interval * 1000, this);
    },

    updateCommute: function(self) {
        Log.info(self);
        self.sendSocketNotification('TRAFFIC_URL', self.url);
    },

[paviro]

What does var self = this; do now? It is no longer referenced in start, is it?

[MichMich]

@paviro removed it ...

[MichMich]

Why it doesn't work if you put it in start, is a bit of a mystery for me. But you can probably live with this, so I go back to bed ... ;)

Still: keep in mind that the current setup doesn't work if people add the same module twice. You should solve that after you get it up and running.

[SamLewis0602]

Yes please do! Thanks again for the help. I hadn't even thought of having multiple of the same module, I'll definitely look into that.

[MichMich]

Best way to do this, is to send the the origin and destination to the node_helper, and return in with the together result. And then let the frontend check if the origin & destination is what is configured for that module. If not, ignore the message from the helper.

(That is how the newsfeed works. It returns the configured rss-url together with the result. If that is different then this.config.feedUrl, the socketNotificaition is just ignored.)

[MichMich]

See this line: https://github.com/MichMich/MagicMirror/blob/v2-beta/modules/default/newsfeed/newsfeed.js#L46

[SamLewis0602]

Ah, that's a clever and simple solution, makes sense. Thanks.

[paviro]

Also the way I did it, but would't it be better to let the client send this.identifier and then let the server send the data back but with the identifier attached? At least I wanted to change my Wunderlist module to do that some day.

[MichMich]

Going back to bed now ... ooh... no, there is someone else in need of some support. A crying baby that wants food ... LOL.

[paviro]

Sleep well and good luck with your baby!

[MichMich]

@paviro Yes, that's a clean way. The added value of using the url: what if you use two modules with the same url, then both modules would benefit from the content update. :)

(And yes, there are situations this could happen with the calendar.)

[paviro]

That's right! So it depends on the type of module you write :)

[MichMich]

Indeed! :)

[MichMich]

In most cases your solution is the cleanest.

[MichMich]

(Until someone opens the interface twice in multiple browsers. Then the shit hits the fan. ;))

[paviro]

Maybe I should add something about the multi instance thing to the docs? Just so its clear for new devs.

[MichMich]

Good idea. Maybe with some simple example code.

[paviro]

I can try. But you'll probably have to overlook it afterwards.

[SamLewis0602]

The only downside of the solution for this issue is that the dom won't update with the commute time until one full cycle of the user defined interval has passed (just the nature of setInterval). Even just calling this.updateCommute() directly above the setInterval seems to cause a problem. So strange.

[MichMich]

Make it a regular function you call directly. And at the end of the function use a setTimout to call itself.

[MichMich]

I noticed the change in your code. If it doesn't work: don't forget to sent self as an argument with the setTimeout.

[SamLewis0602]

Thanks for the catch. Ultimately, back to the same issue where the first socketNotification works but subsequent ones are nowhere to be found, despite the function being called multiple times (stuck a Log of the url inside updateCommute to make sure it was calling itself).

[MichMich]

That is really weird. I'll look into it somewhere this week.

[SamLewis0602]

I've got to go to class so I'll have to mess with it some more later. Get some sleep! Thanks again for the help.

[SamLewis0602]

I'll let you know if I am able to figure anything out.

[MichMich]

Ok, the issue is solved: there was a huge bug that caused the issue that only the last configured module could keep sending socketNotifications. This is solved now.

I close this issue, but feel free to keep using this issue if you need any help building your module.

[SamLewis0602]

Great! Everything is working now. Thanks again for your help!

[SamLewis0602]

Okay, I've updated it to work for multiple instances of the module and everything is working based on my tests. Please check it out and let me know if you have any suggestions!

I was thinking of adding an option to show the destination in small, dim text on a line underneath the current view, in case people want to be able to easily differentiate between routes if they have multiple. What do you both (or anyone else reading this) think?

[SamLewis0602]

Also here is another link to the code so you don't have to go searching through the conversation above: https://github.com/SamLewis0602/MMM-Traffic

[pvyParts]

the address might be a bit long but it could be dimmed out nickname of the locations like the card in google now
"Home to Work"

or could do both if no "nickname" is set for the origin/dest use the address

( i've not tested the module yet but will tonight )

[SamLewis0602]

Ah that's a good idea. Maybe just something like a routeName field that will allow them to call the route whatever they want. Then there would be no need for a showDestination, but rather I could just show the routeName in the DOM if it exists. Thanks!

[SamLewis0602]

Okay, support for route_name in the config file has been added. I'll add it to the README now. Let me know what you think!

[CFenner]

@paviro: If in the handler itself you don't need the original this you can override it like this.

setTimeout(
  this.handler.bind(this),
  this.config.updateIntervall
);

or

setTimeout(
  function(){
    //doSomething
  }.bind(this),
  this.config.updateIntervall
);

[MichMich]

Great work @SamLewis0602! I'm using your module on my mirror. My girlfriend asked me for this features a few days ago! :)

I ended you a pull request with multi language support. This way it can be used in other languages as well.

I'll continue further question/issues in your repro te keep everything in one place. :)

[paviro]

Don't forget to add your module to the wiki, so that others can find it! Will give it a try later, thanks for your work!

Am 20.04.2016 um 09:58 schrieb Michael Teeuw [email protected]:

Great work @SamLewis0602! I'm using your module on my mirror. My girlfriend asked me for this features a few days ago! :)

I ended you a pull request with multi language support. This way it can be used in other languages as well.

I'll continue further question/issues in your repro te keep everything in one place. :)

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[paviro]

@CFenner will try that thanks!

[kapsolas]

I seem to be having a similar issue that I can't figure out..

Just setup the Mirror and looking to write some modules. Trying to get the notifications to work before I start building out code and it isn't working.

In my module.js file I do the following

in the start method I do the following

start: function () {
    Log.info ('Starting module: ' + this.name);
   this.url = ''; // I have a method that generats the URL and it works ok

   this.grabPhotos();
},

grabPhotos: function() {
  self.sendSocketNotification("MyNotification", this.url);
}

In the node_helper.js the code is as follows

var NodeHelper = require('node_helper');

module.exports = NodeHelper.create( {
  start: function() {
    console.log("Starting helper module");
  },

  socketNotificationReceived: function(notification, payload) {
    console.log("notification received");
  }
});

I never see any notifications reached.. I even tried to pass this in grabPhotos() and then use self, but it did not work... Stumped for a few hours. not sure what the issue is.

Thanks!

EDIT: I installed the mmm-systemtemperature module also to step through it. it does not work either. Was something messed up in the last update? I did a git pull and it states I have the latest.

[MichMich]

You are running sendSocketNotification on self., but it doesn't seem like you initialized the self var. try this.sendSocketNotification .

[kapsolas]

I have tried with this as well with no difference.

To make sure I didn't have any code issues. I installed the mmm-systemtemperature module, and it does not work either. Making me thing maybe its something else?

[MichMich]

What version of node are you running?

[kapsolas]

The version I have is v6.2.1

[MichMich]

Do all the other default modules work?

[kapsolas]

Yes. thus far, all the other default modules are working.

I even modified the hello world as a start to display an image using just an

I updated the config and added new RSS feeds to the newsfeed, that also worked fine.

[MichMich]

Could shrare your repository somewhere so I can try?

[kapsolas]

Sure!

I made a pastebin with both the files since I don't have a repo set up for it yet on github.

The link is good for 24 hrs. after that I set it to expire.
http://pastebin.com/GHpg5J9X

At this point, the UI is not wired up. I'm just trying to get the notifications to work and checking for messages in the console.

Once I get that working, I will be coding it up to parse an RSS feed from Flickr and pull images to rotate through.

thanks for your help!

[kapsolas]

No need to try the repository. Not sure what the problem was, but I
rebooted the raspberry pi zero and my PC and stuff started to work..

Part of the my issue was that I expected the console.log to write to the
Console log in firebug, but it does not. It literally goes to the console
where you kick-off the process!

My module is complete at this time, it loads images from Flickr and
animates them!

If people are interested in this, I can upload it to my github.

Thanks!!

On Sat, Jul 16, 2016 at 10:26 AM, Michael Teeuw [email protected]
wrote:

Could shrare your repository somewhere so I can try?

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