leptos VS xilem

Lots of new frontend frameworks have been built on top of Rust, including Leptos, which happens to be one of the most popular ones. In this guide, we'll highlight why and how to migrate your JavaScript frontend to use the Leptos Rust frontend framework.

I don't know why OP felt moved to write this weird guide, https://leptos.dev is incredible!

https://github.com/leptos-rs/leptos/blob/main/flake.nix

You want a package? Add it to buildInputs.

You want to search a package: https://search.nixos.org/packages (or use the cli)

you want to test a package before adding it? nix-shell -p or nix shell for example.

Heck, even if you want it more easy, you could write a tool in less than 100 lines that adds packages names to .json/.yaml/.toml, which allows you to parse it using the nix language and a simple cli written with bash functions to add/remove packages if you wanted.

That's why it is hard for me to understand this project as a product, it seems like a wrapper to the most basic things :\

We use the fantastic Leptos framework for building the frontend. Besides that, we use the leptos-use utilities for connecting to the WebSocket server, serde for serialization, and rand for generating random numbers.

I'd use https://leptos.dev because you can use a fully typed language (Rust) that is super fast in the backend and also in the frontend (see https://krausest.github.io/js-framework-benchmark/2024/table...)

For the web-side, if you'd like to use Rust end-to-end we've had the best experience with Leptos: https://leptos.dev/

I'd suggest https://leptos.dev/ is worth a look. I haven't used it yet, but plan to soon.

I think a lot of us reach for Jinja-style templates so it feels a little more like we're writing bare HTML. But they're of course still just templates, and they need a build step before they become valid HTML.

So it's true, if you're willing to use a DSL embedded in your server language (like JSX), then you'll have the full language tooling available to you. And this probably isn't giving up much over language-specific templates.

A JSX-equivalent for the Rust server-side rendering world would probably be maud [1] or leptops [2].

[1] https://github.com/lambda-fairy/maud

[2] https://github.com/leptos-rs/leptos

I wanted to deploy the app serverlessly, opting for Deno Deploy hosting. The JS fetch example and the leptos-deno examples were handy to get me going.

The web browser gives us an extremely frictionless development and deployment process. Our CI generates a fully deploy at a unique link for every commit which lets us open and test PRs with a single click. It deploys updates to users without needing to make them go through an updater. In these relatively early stages of our development process, the importance of the velocity that gives us cannot be understated. Plus, the ability for users to try it out in one second is quite helpful.

I've designed the whole architecture specifically to avoid the web UI "feeling like a web app" with the subtle latency of interacting with the site. I wrote all-custom UI components using the minimal amount of HTML and CSS to achieve the requirements instead of depending on an external component framework which always loves nesting dozens of `div`s inside each other to achieve what should be doable in one or two. And our highly-lightweight JS which calls into Rust (Wasm) lets it keep the slow logic out of slow JS. And we are using Svelte to move most of the frontend DOM management logic from runtime to compile time. This architecture really helps us keep performance levels as close as possible to feeling native despite using the web for its GUI rendering; and I believe it has succeeded at feeling responsive by comparison to most other web apps you use (even Slack, for example, which shouldn't be nearly as complex).

Web lets us build fast, deploy the latest version to users fast, leverage prevalent developer experience with HTML/CSS for creating GUIs, and avoid getting stuck in a box with Rust's currently-immature GUI ecosystem. That's the tradeoff we had to make early on, and it was a good decision. But we will eventually move towards a fully native version...

In the short term, we plan to use [Tauri](https://tauri.app/) which is sort of a hybrid between Electron and a native application. It uses the OS's webview to shrink the shipped binary to only a few megabytes and reuse shared memory resources with other webviews at runtime. It also runs all our Rust code natively instead of through WebAssembly so all the business logic in Graphite runs natively and only the thin UI layer becomes dependent on web tech for the GUI display.

In the long term, we plan to rewrite the entire GUI in [Xilem](https://github.com/linebender/xilem) which is the up-and-coming Rust GUI that I believe will finally get everything right, including performance (which is something many desktop GUI frameworks are actually bad it, and sometimes even worse than web). We'll still deploy a web version but at that point, it will become native-first.

Hopefully that roadmap and explanation of the architectural decisions clears up any worries about the short and long term state of our GUI.

That said, Xilem is very close to that idea, but it's in its very early stages and nowhere near Flutter's capabilities.

xilem#62 demonstrates how Xilem's reactive layer can target DOM nodes.

Inspired by Xilem, Leptos and rui, Floem aims to be a high performance declarative UI library with minimal effort from the user.

There are a number of up-and-coming Rust-based frameworks in this niche:

- https://github.com/iced-rs/iced (probably the most usable today)

- https://github.com/vizia/vizia

- https://github.com/marc2332/freya

- https://github.com/linebender/xilem (currently very incomplete but exciting because it's from a team with a strong track record)

What is also exciting to me is that the Rust GUI ecosystem is in many cases building itself up with modular libraries. So while we have umpteen competing frameworks they are to a large degree all building and collaborating on the same foundations. For example, we have:

- https://github.com/rust-windowing/winit (cross-platform window creation)

- https://github.com/gfx-rs/wgpu (abstraction on top of vulkan/metal/dx12)

- https://github.com/linebender/vello (a canvas like imperative drawing API on top of wgpu)

- https://github.com/DioxusLabs/taffy (UI layout algorithms)

- https://github.com/pop-os/cosmic-text (text rendering and editing)

- https://github.com/AccessKit/accesskit (cross-platform accessibility APIs)

In many cases there a see https://blessed.rs/crates#section-graphics-subsection-gui for a more complete list of frameworks and foundational libraries)

Yeah, Druid is being replaced by Xilem, but unfortunately Xilem isn't ready yet. So that whole project's in a bit of an awkward in-between phase where there isn't really any toolkit that can be recommended.

Third, we are discontinuing Druid proper. Years of experience has shown that people can struggle with the Druid data architecture and we can do better. This layer will be replaced by a new project called Xilem. We have spent a lot of time thinking about it and this decision was not taken lightly. You can read a more detailed post about the Xilem architecture but the gist of it is that we've found at a way to code UI in Rust that feels a lot more effortless than previous attempts. Xilem will look very intuitive to those familiar with state of the art toolkits such as SwiftUI, Flutter, and React, while at the same time being idiomatic Rust. Also we plan to port as many widgets from Druid to Xilem as possible, which should give the project a reasonable timeline to v0.1. Hopefully later this year.