I have a node.js app that sends live data to the client via socket.io (Websocket transport) to draw a canvas (the client receives and uses data to draw to canvas).
I use socket.io-client to connect to the socket.io server.
This works fine (at least to an extent) on PC but very slow on mobile devices (that support WebSocket).
Note: App is hosted on Azure and I am saying most data on Local Storage for better performance.
What can be the cause of the lagging and frequent disconnection on mobile phones but good connections on PCs?
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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 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.
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.
I have a web application that requires PUSH notifications. I looked into node.js and socket.io and have an example that's working. The question I have is, Is it possible to use socket.io only in my client side JS without running a node.js server?
Can a third party server just send requests to a proxy server and may be socket.io just listens to a port on the proxy server and sends back events to it?
Thanks,
You need a server side technology to send data back and forth via web sockets. Socket.io is a communication layer. Which means, you need to have a server side method to send data.
However,
You can use various third party services to use web sockets and notifications. They are relatively easy to use, and they have support for many other languages.
Check some of these out:
http://pusher.com/
https://www.firebase.com/
http://www.pubnub.com/
https://www.tambur.io/
https://fanout.io/
You don't need to run Node.js to have a real time push notifications. You can use a third party service that does it for you. Most of them are cheap, sometimes free for low traffic instances.