htmx sorta

A demo project where I learn and play with my "Rust web stack":

Rust
Nix flakes for building and dev shell
redb Rust local key-value store database
astra Rust web server library
maud Rust html templating library
htmx for dynamic html frontend
tailwind via twind for CSS styling

In essence it's a TODO app, and looks like this (click for a video):

Note: server response slowness is simulated to help improve the UX. The imgur "optimized" the video and now it's slow and laggy, but I have no energy to fight with it right now. In reality things are working just fine.

Some of the features: persistent ordered list, with drag'n'drop UX, responsive html, graceful offline handling, rate limiting.

I think it might be source of inspiration and example for people that would like to use a similar set of tools for their own projects.

Running

If you're a Nix flake user you can run nix run github:dpc/htmx-sorta. Otherwise, proceed like with any other Rust project.

About the stack

I like things simple, small and to the point. Also - it's a bit of a research project, so I'm not afraid to try out things that are not most popular and trendy.

I'd like to avoid using async Rust, because it's immature and PITA to use, while blocking IO is perfectly sufficient. That's why I use astra, which is very promising blocking IO Rust web framework/library.

I don't want any C-binding based dependencies, and that's why I'm using redb, which is very promising and lean key value store, in a similar category as e.g. RocksDB.

I don't like DSL, especially looking like combination of Python and HTML, so maud is my favourite HTML framework. Again - fast, lean, to the point.

I'm tired of all the SPAs that are slow heavy and barely work. I'm more of a backend developer than a frontend developer. I think HTMX is the direction that Web should have taken long time ago, instead of betting everything on Javascript. I'm not afraid of adding JS to the code, but it shouldn't be for UX niceness and not the tail wagging the dog.

I'm not much of a designer or a web developer, but I've did some web projects over last two decades, and I wholeheartly agree with Tailwind philosophy. Unfortunately it doesn't have a great Rust/maud integration, so I use twind as a client-side Tailwind JIT instead.

Points of Interest

Check maud templates in fragment.rs, acting like web-components for both htmx and tailwind.

Route handlers are in routes.rs. They are a bit low level and manual but hopefully astra will get some more convenient approach (e.g. like Axum extractors) in the near future. The developer is working on it. Go say hello if you're interested.

The Nix dev shell I'm using sets up automatically some cool git hooks. I keep using it in many projects. It includes semgrep, typos (checking typos), convco (conventional commits), linters, and some Rust specific checks.

mold is used to speed up linking, with symbol compression enabled to make the binary smaller (6.3 MiB ATM).

I've "invented" a variable-length sorting key approach, that simplifies item sorting. It makes generating a key between two other keys a simple and infaliable operation.

I had an idea for compact and fast, but imprecise pre-rate-limiter that I think would be very fast. It uses a multi-hash approach with buckets of atomic counters, kind of like bloom/cuckoo filters, to effective take one atomic (relaxed) write on the happy path, and gracefully degrade under heavy load. Did not have time to benchmark it, so 🤷. Maybe it's stupid.

The rest is somewhat typical. As of the time of writing this there are some known missing things. It's just an demo/research, don't expect too much.