chat VS askama

TUIs over ssh/telnet can be a lot of fun. Especially in cases where multiple people can interact with each other on the server. It simplifies the programming model as you only have one state on the backend that you render to multiple connections. Syncing up everyone becomes trivial. You can also use some React concepts, like rendering a virtual TUI and sending just the right set of minimal escape sequences back to the user to bring their display up to date.

A few months ago I implemented a telnet chat server[0] for fun and it was surprisingly easy to do so. Even by using a wasm vm that I was still working on at the same time.

[0]: https://github.com/lunatic-solutions/chat

We are investing a lot of effort into making Lunatic feel native to the particular language and ecosystem. If you look at the Rust chat server we built in Lunatic (https://github.com/lunatic-solutions/chat), it fully integrates with cargo. You just run your typical “cargo run” command, it will compile the app to wasm and use lunatic to run it. If you want to run your test, you can just do “cargo test”.

wasm-bindgen is necessary only because it’s really hard right now to merge the wasm world and the JS one in the browser. We have the advantage here of staying out of the browser.

It took me around a week to build it with Rust + Lunatic and you can check out the code here. If you would like to try it out you can connect to it with:

Recently I implemented a command line chat server in Rust using an actor framework. I model each TCP connection as an actor.

Hi HN,

I'm working on an Erlang inspired WebAssembly runtime for the backend[0]. Recently I added TCP support and was looking for apps I could build with it. I ended up building a telnet line chat app. It was a great dogfooding experience and has a nice retro feel to it.

You can access the US server with:

> telnet lunatic.chat

or the EU one with:

> telnet eu.lunatic.chat

Pick the one closer to you, as all the rendering is done on the backend and lower latency will mean better UX.

The server is open source[1] and written in Rust. The Rust code is then compiled to WebAssembly and runs on top of Lunatic. Each connection runs in a separate (lightweight) process, has it's own state and sends just a diff of esc-sequences back to the terminal to bring it up to date with the current render buffer. Everything is deployed to an ARM Linux box.

[0]: https://github.com/lunatic-solutions/lunatic

[1]: https://github.com/lunatic-solutions/chat

The server is open source and written in Rust. The Rust code is then compiled to WebAssembly and runs on top of Lunatic. Each connection runs in a separate (lightweight) process, has it's own state and sends just a diff of esc-sequences back to the terminal to bring it up to date with the current render buffer. Everything is deployed to an ARM Linux box.

I have inlined the CSS here, and you can use Rust-based tooling like Lightning CSS to minify and bundle CSS here. You might also want to create a Rust build script to generate the HTML from a template, using the askama crate (works a little like Jinja).

This adds askama itself as well as the Responder trait implementation for the askama::Template type. askama expects your files to be in a subfolder of the project root called templates by default, so let's create the folder and then create an index.html file with the following HTML code in:

You can also use HTML templating with crates like askama, tera and maud! This can be combined with the power of lightweight JavaScript libraries like htmx to speed up time to production. You can read more about this on our other article about using HTMX with Rust which you can find here.. We also collaborated with Stefan Baumgartner on an article for serving HTML with Askama!

This is such a great project, thank you for sharing! It seems like you're getting the usual dump of negativity around HTMX... but as usual, not much coming from anyone who's actually tried to build something small/medium-sized. I keep hearing that this stack "would" fall apart in a bigger project, but I never hear any concrete, empirical descriptions of issues that actually do arise.

I'll offer one here... using HTMX usually means you're going to be writing HTML templates, and HTML templating languages don't have much IDE support. I really miss goto-definition etc. when I'm writing Jinja templates.

That being said, I've personally found Rust/HTMX to be a magnificent combo. I personally find writing backend endpoints in Rust to be no more cumbersome than any other language (after becoming comfortable with Rust)... and there's massive gains from the incredible tooling and type system.

I wonder if you've considered using Askama for your templates? It has a Axum integration that cleans up some of the boilerplate around template rendering. There's also an open PR for block fragments [1], which will make componentization of HTML fragments much easier, as discussed in this essay on the HTMX site [2].

We need more projects like this to demonstrate how useful, highly-interactive apps are made with HTMX. I'd encourage skeptics to try the same before writing it off.

[1] https://github.com/djc/askama/pull/824

This templating languge / engine is heavily inspired by Askama, but brings more rust into your template code. The project is still in early stages and is likely filled with bugs but I wanted to get something out there to get some feedback on.

Askama

Rust allows me to mainly only run the application to confirm things work from a business perspective.

For people starting out building stuff in rust - understand that there is a distinction of async code and libraries and can lead to confusing compiler errors if you don't realize there is a distinction. It's simple in hindsight but did cause me to waste hours barking up the wrong trees at first. Other wise just learn about `match` and Result/Option types asap, they're fundamental.

https://github.com/http-rs/tide tide is great to create an http server / routes

https://github.com/djc/askama I use this to template out HTML and it checks all my boxes, dynamic data, passing in functions, control flow.

https://github.com/launchbadge/sqlx sql interface for a variety of backend, async safe.

https://github.com/seanmonstar/reqwest http client to make requests

Rust is amazing, don't let the initial few speed bumps discourage you - building real things with rust is no more challenging today than any other modern language stack.

I also Suggest using https://crates.io/crates/askama for Templates. even though it can be hard to get use to and they are compile time only It allows you to use Rust functions directly within the Template code. Which can make your life easier.

It was a bug in askama that was fixed. The solution is to use a newer version that contains the fix, but they have not released a new version of askama since fixing the bug, so 0.11.1 still contains the bug. It seems like 0.12 has been a long time coming but should finally be coming soon: https://github.com/djc/askama/issues/722

A good example is Askama, which should look good to folk from the python / django / jinja world: https://github.com/djc/askama