andarotajo
How do I build a WebSocket client library?
Hello, I’m very new to Elixir and looking to get started on a little project I’m interested in. Inspired by this blog post I’d like to build a “simple” client library giving users a simpler way to use Home Assistant’s WebSocket API.
I think a library like this give users the most flexibility in how they write automations and keeps the project scope limited for my own sanity 
But since Elixir and writing libraries in general are very new to me, I’d love to get some pointers on how to go about that. Things I’ve been wondering:
- I thought about building the library around callbacks, e.g. a callback for Home Assistant’s state changes, allowing the user to pattern match what they need. How do I build a WebSocket client around this concept
- Is using a GenServer the way to go? I’d need to keep a state
- Besides the URL there’s also a token I’d need to connect to Home Assistant. Is there a “best practice” on how to configure stuff like this?
Some good libraries I can use as guidance for code quality and stuff would probably help if you’ve got some suggestions.
For reference, this is Home Assistant’s WebSocket API
Thank you very much for helping!
Trending in Questions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
We build reliable cloud platforms for business-critical systems.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #blog-post
- #phoenix_html
- #iex
- #graphql
- #genstage
- #ai
- #elixirconf-us
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #hex
- #performance
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Practical resources that improve the lives of professional developers.
Develop your skills with books, videos, and courses.
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
First 4 of 4 Posts
jstimps
I like to use gun for client-side ws work. A while ago I wrote a little Livebook example to remind my future self of the function calls involved.
bbangert
I recently extracted a websocket lib for HA that I published on hex: Hassock — hassock v0.1.3
This uses the newer HA command that uses diff’s for efficiency with an optional ETS cache for faster queries without sending everything over the websocket connection.
andarotajo
Thanks for the heads up! To be honest I didn’t touch Elixir much after experimenting around a bit but this project is still on my list for when I finally learn Elixir.
Looks great on first glance. Have you tried writing an automation with it or plan to?
bbangert
Currently I use this library on a bit of a test project to control a LoupeDeck Live device ( GitHub - bbangert/loupey: Elixir library for Loupedeck devices · GitHub ). I’ll eventually bake this into a Nerves project and add Elgato StreamDeck support, so that its easy to have stand-alone physical Home Assistant controls and displays with a bit more powerful software backing it than what ESPHome can do.
My Loupedeck mainly acts as a display and control for HA, so I can turn the volume knob to change the volume of my audio deck, tap a touch slider to change the light levels that HA controls via Phillips Hue, and I have some buttons that just display sensor states.