Just finished reading about Phoenix Channels and now im confused on how i can use channels with LiveView to sync my page with everyone who is using the page.
Quick Trip with AI is telling me to use PubSub. When i try to check out the LiveView Hex Docs for guidance on how to use pubsub or channels with LiveView, i couldnt find any material on it.
I just wanted to learn more about the combined usage and its best practices, let me know if both usage is fine but i still wanna know what the community best practice and use case on when to use channels and when to use PubSub with LV.
You might want to look at Matrjoschka of phoenix communication | Benjamin Milde. It should make the distinction between the tools more clear. Generally the question will be why you need channels – not just PubSub – when you already have LV running (on top of channels).
I guess you are quite new to elixir and phoenix. So I will try my best - I am not good at explaining
The LiveView model allows live communication between the server and the client browser. But each user is served its own instance of the LiveView. So they do not know of each other.
The PubSub part allows you to send the same message to all subscribers, so you can notify them about changes.
In your case, you would subscribe to a specific PubSub message from the LiveView. And in the LiveView you handle the PubSub message.
You could, for example, broadcast a {:content_updated, 134} message. And the LiveView then knows, that it has to reload the data for that id.
Not full example, but perhaps to explain the difference between the concepts.
Namxam has it right. The only thing I’d add to answer your original question is: if you’re using LiveView you can ignore the Channel documentation. Just focus on LiveView and PubSub. Channels are useful when you’re not using LiveView, e.g. you have a separate frontend.
And that’s because Phoenix.LiveView.Channel builds on top of Phoenix.Channel which is why you might not need to interact with Channels directly when you are already using LiveView
Sometime ago, I published a blog post about how I built a turn-based battle game prototype, which uses PubSub to push state to multiple clients/players. If you are into gaming, the theme might ease you into my poor didactics .
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