I have a MQTT bridge and I needed a GUI for it to show status of connectivity and metrics such as how many locally connected devices, messages received from local devices.
Both the MQTT bridge and the GUI will be on the same raspberry pi.
Looking through the options, but it seems that making the GUI as a web, running in Express, and connects to the MQTT bridge (mosca) via websocket over localhost, is the only option?
Is there other UI framework in NodeJS that supports model bindings without having to do an connection with the localhost? Trying to reduce the number of connections to the MQTT bridge which is a Mosca server on NodeJS.
Putting in another way: I noticed Desktop Apps using ExpressJS does not support modal bindings, and if there is any change of values such as new clients connected to the server, I need to reload the whole page? I can achieve modal bindings with a web page with say AngularJS, but it also means the web app is isolated from the MQTT server running NodeJS. I am just wondering if there is any framework that I can merge web JS and backend NodeJS into single app.
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I'm trying to develop a web application in nodejs. I'm using an npm package called "simple-peer" but i don't think this issue is related to that. I was able to use this package and get it working when integrating it with a laravel application using an apache server as the back end. I could access the host machine through it's IP:PORT on the network and connect a separate client to the host successfully with a peer-to-peer connection. However, I'm now trying to develop this specifically in node without an apache back end. I have my express server up and running on port 3000, I can access the index page from a remote client on the same network through IP:3000. But when I try to connect through webrtc, I get a "Connection failed" error. If I connect two different browser instances on the same localhost device, the connection succeeds.
For reference: i'm just using the copy/pasted code from this usage demo. I have the "simplepeer.min.js" included and referenced in the correct directory.
So my main questions are: is there a setting or some webRTC protocol that could be blocking the remote clients from connecting? What would I need to change to meet this requirement? Why would it work in a laravel/webpack app with apache and not with express?
If your remote clients can not get icecandidates, you need TURN server.
When WebRTC Peer behind NAT, firewall or using Cellular Network(like smartphone), P2P Connection will fail.
At that time, for fallback, TURN server will work as a relay server.
I recommend coTURN.
Here is an simple implementation of simple-peer with nodejs backend for multi-user video/audio chat. You can find the client code in /public/js/main.js. Github Project and the Demo.
And just like #JinhoJang said. You do need a turn server to pass the information. Here is a list of public stun/turn servers.
I want to create an application in which my web app will work as remote , a node based web socket server will work as CMS(central management system) and an electric vehicle charger which will be my device. I want help in how to send instruction to my device according to the commands i receive from it.
You can use socket.io on your server, it is easy to use and has a socket client implementation in almost languages that exist.
I created an Electron for a tiny company that connects to a Socket.io server. This app obtains the username of the logged in user and the MAC address and sends this info to the server for processing. All of this is working fine with regular desktops. Now, another company wants the same app, but they have a thin client architecture. Is there a way to get the app to run in this kind of architecture?
I am having a hart time figuring it out. I have never dealt with thin clients.
1) In the thin client architecture, would I have my socket.io server code and the app in the same server then? If they are in the same server, how could I get the app to connect to the socket.io server? They are in the same machine, so I am confused.
2) One problem is the app can't obtain the MAC of the thin client because once executed from the thin client it will end up getting the MAC of the server. Is there a way to obtain the MAC of the thin client using Node.js? Is there another way of using Node to recognize some sort of id for the thin client?
I would like the thin client to log in to the server, execute my app automatically, connect to the socket.io server, and send to it the username of the logged in user and the MAC address of the thin client. Is this possible? Do you have any suggestions on how to accomplish this?
You have to use the serverside code of the library for your server. E.g. node express.
Then you have to use the client side code of the library in a client side application. E.g. electron
Electron is a combination of node and chromium and you have to install the final build on the clients machine(s).
Of course, you can do all the things you ask about. Just read the socket.io docs. Its very easy, you can do it by specifying the host IP and listening/emitting events.
I have this IoT device that I am trying to connect to the server via wifi to send real time data. The server uses socket.io with node.js, but the wifi module (esp8266) I am using only has a websocket package. Would a socket.io connection be able to receive data sent via websocket?
Yes, but it will be a bit of a kludge:
socket.io supports multiple transports, of which one of them is a websocket. You can connect using only the websocket, but you will need to implement the socket.io protocol.
https://github.com/socketio/socket.io-protocol
If you are using a popular platform, there may be libraries available, i.e. for Arduino, there is:
https://github.com/billroy/socket.io-arduino-client
I have a program in an embedded device that outputs an xml string to a socket. The embedded device has lighthttpd has a web server. I want to use a web based client (no flash/silverlight) to connect to the socket and pull the xml data every second.
I looked at Node.js with Socket.io to get what I want to do, but I am not clear about how to proceed. Searching through the Node.js and Socket.io documentation and examples I see standard client-server behavior, nothing regarding what I am trying to do.
Basically, the web server is just there to accept a connection from a client on the socket that the embedded application is outputting data to. Basically the web server's purpose is to just let the client retrieve data from the raw tcp socket that the embedded application is writing to. Please advice.
I solved the problem using Websockify, which acts as bridge between a TCP Socket and a browser.
The html client will connect to a websocket, and Websockify will listen on the websocket port and transmit data between the websocket and the tcp socket.
Web browsers have the ability to do HTTP requests (which can be web page requests or Ajax requests for data) and webSocket connections. You will need to pick one of these two mechanisms if you're sticking with stock browser access.
If the lighthttpd web server in the embedded device does not support webSockets, then your choice will like be an Ajax call from the browser to your server. This is basically just an HTTP request that make return something different than a web page (often JSON data) and is designed to fetch data from the server into a web client.
If the lighthttpd web server does support webSockets, then you could use a webSocket connection to fetch the data too. This has an advantage of being a persistent connection and allows for the server to directly send data to the client (without the client even requesting more data) whenever it wants to (more efficient for constant updates).
An Ajax connection is generally not persistent. A client sends an Ajax request, the server returns the answer and the connection is closed. The next request starts a new Ajax request.
Either Ajax requests or webSocket connections should work just fine for your use. All browsers still in use support Ajax. WebSockets are supported in modern browsers (IE10 and higher).
Once you decide upon a client connection strategy, then you'd build your web app on the embedded device that served as the middleman between the browser and the data on the embedded device. It would collect the appropriate data from the embedded device and then be able to send that to browser clients that connected and requested the data.
I'm not sure exactly why you mentioned node.js. In this circumstance, it would be used as the web server and the environment for building your app and the logic that collects the data from your device and feeds it to the requesting web browser, but it sounds like you already have lighthttpd for this purpose. Personally, I recommend node.js if it works in your environment. Combined with socket.io (for webSocket support), it's a very nice way to connect browsers directly to an embedded device. I have an attic fan controller written in node.js and running on a Raspberry Pi. The node.js app monitors temperature probes and controls relays that switch attic fans and node.js also serves as a web server for me to administer and monitor the node.js. All-in-all, it's a pretty slick environment if you already know and like programming in Javascript and there's a rich set of add-in modules to extend its capabilities available through NPM. If, however, your embedded device isn't a common device that there is already support for node.js on or it doesn't already have node.js on it, then you'd be facing a porting tasks to make node.js run on it which might be more work than using some other development environment that already runs on the device like lighthttpd.