Show HN: Sycamore – next gen Rust web UI library using fine-grained reactivity (sycamore.dev)
89 points by lukechu10 7 hours ago
electrograv 6 hours ago
IMO a UI library landing page should always contain a screenshot example of the UI.
I can’t find a screenshot of it anywhere, let alone the landing page.
josephg 6 hours ago
It looks like this is a web UI library, so it would just render using regular html.
I wish they said that on the homepage. I assumed it could render to the desktop or something, and I had to read tea leaves to figure that out.
simonbw 2 hours ago
The first sentence of this page says it:
> Sycamore is a next gen Rust *web* UI library powered by fine-grained reactivity.
lukechu10 2 hours ago
FrustratedMonky an hour ago
Tuna-Fish 6 hours ago
The landing page is the screenshot. It uses sycamore.
simlevesque an hour ago
Well, then something's wrong. I click on different pages in the documentation and the whole page gets rerendered. Seems like it's not delivering what's promised.
TechSquidTV 6 hours ago
Unless maybe it's headless, then I still expect a component library or something. Still, I see nothing.
lukechu10 6 hours ago
It's more like ReactJS/SolidJS (but in Rust) rather than a component library like Bootstrap. Although I definitely agree the home page can do a much better job of explaining this.
Flavius 2 hours ago
"Read the Book" button, next gen web UI. That's all you need to know about this one.
FrustratedMonky an hour ago
I'd like to know why i'm bothering to read the book?
Maybe sell it some.
Next Gen UI. Bold sounding, show it.
ordu 22 minutes ago
gwbas1c 5 hours ago
> Reactive Apps with Effortless Performance.
> Sycamore is a next generation Rust UI library powered by fine-grained reactivity.
It's not clear on the landing page that this is for in-browser UI, as opposed to desktop UI and/or mobile UI.
I would make it completely unambiguous that Sycamore is for web applications.
lukechu10 5 hours ago
Ok I've modified it slightly.
But Sycamore does have ambitions to have native GUI support as well. I'm currently looking at GTK, Iced, and GPUI and see if it would be possible to add Sycamore support. This would make it possible to create GTK, Iced, or GPUI apps using building blocks from Sycamore.
airstrike 5 hours ago
Once upon a time there was iced_web https://github.com/iced-rs/iced_web
FWIW, as an iced user, personally I'd prefer to write iced and use something like sycamore to build for the web rather than the other way around
lukechu10 5 hours ago
dewey 6 hours ago
In the footer: "This website is also built with Sycamore. Check out the source!" https://github.com/sycamore-rs/website
wsowens 5 hours ago
I looked briefly, but is anyone aware of the differences between Yew[1] and Sycamore[2]? Presumably they are both Elm-influenced(?) Rust web UI libraries named after trees, but it's unclear to me why I should use one versus the other.
basro 4 hours ago
They differ in a similar way to how React differs from SolidJS.
In react when state changes the component functions that depended on that state are rerun to compute what the component should now look like. Then react diffs the new output with the previous to touch only the parts that changed in the DOM.
In solidjs the component function runs only once (when the component is instantiated), when state changes signals will trigger and cause the specific parts of the DOM that depended on them to change. This is generally more efficient.
pstomi an hour ago
I looked at your doc book (https://sycamore.dev/book/guide). I suppose it uses sycamore itself. Do you plan to add a search to it?
(if the "search implementation" is readable enough, it may perhaps also serve as teaching material :-)
lukechu10 an hour ago
Yes I plan on adding doc search. Although I'm not sure if I should try to build one from scratch (never tried building full text search before) or using something prebuilt like Algolia docsearch.
pstomi 21 minutes ago
Algolia docsearch would host an AI view of the doc, on its own website with its own stack, no?
It resembles deepwiki (which I used on several of my projects, see for example https://deepwiki.com/pthom/imgui_bundle).
If algolia is close to deepwiki as I suspect, that does not replace the original doc site: it needs to index an existing doc site before. So adding (even a simple) search to this site would be worth it imho.
embedding-shape 7 hours ago
The website mentions "giving you full control over performance", what are those knobs and levers exactly? What does those knobs and levers influence, and what sort of tradeoffs can you make with the provided controls?
lukechu10 6 hours ago
Unlike other UI libraries, I would say Sycamore has a very clear execution model. If you've used something like React before, there is all this thing about component lifecycles and hook rules where the component functions run over and over again when anything changes. This can all end up being fairly confusing and has a lot of performance footguns (looking at you useRef and useMemo).
In sycamore, the component function only ever runs a single time. Instead, Sycamore uses a reactive graph to automatically keep track of dependencies. This graph ensures that state is always kept up to date. Many other libraries also have similar systems but only a few of them ensure that it is _impossible_ to read inconsistent state. Finally, any updates propagate eagerly so it is very clear at any time when any expensive computation might be happening.
For more details, check out: https://sycamore.dev/book/introduction/adding-state
bickfordb 6 hours ago
The Dioxus library seems really similar to me. How is Sycamores model different?
lukechu10 6 hours ago
mapcars 6 hours ago
With Tauri you also get the freedom of choosing frontend frameworks and can reuse existing frontend code/skills. Yes React has issues, for example Svelte handles reactivity in a much better way. I don't see real benefits of re-implementing the whole thing in Rust.
truefaxxx 5 hours ago
hrmtst93837 32 minutes ago
cma256 5 hours ago
I really like these projects but missing from them is genericity. If you're taking the time to build a WASM app in Rust it would be nice if that app could compile to something other than WASM. For example, looking at the sycamore website's source I see p, h1, div, etc. What I'd rather see is "row", "column", "text". In their source I see tailwind what I'd rather see is "center", "align right", etc.
In other words, elm-ui but for these WASM Rust apps. Building a mobile app, a desktop app, and a web app, in my mind, should be accomplish-able given the right primitives (without requiring a JavaScript runtime be bundled). Rust's multi-crate workspaces make it a really great candidate for solving these cross-platform problems. IMO of course.
0x3f 5 hours ago
If you're not targetting mobile, why diverge from XHTML at all?
cma256 5 hours ago
Are there native frameworks which use XHTML? Regardless, a document language being used to construct complex, interactive GUIs is incidental complexity. XHTML can be a compilation target but it does not need to be a development target.
0x3f 5 hours ago
kevincox 3 hours ago
No browsers support streaming parsing of XHTML so you are slowing down pageloads. Especially for longer pages.
Also the ecosystem is really not there for XHTML, it never really took off. In practice it is close enough to HTML that it probably mostly works, but you are going to have problems.
The advantage is also very small, your emitter is simpler (you don't have to special case void elements and whatnot) and if you need to consume your own pages the parser is simpler. But that isn't worth much for most people.
It does make me sad, because parsing and even emitting HTML is a nightmare. But it won, so at the end of the day I find it easier to just accept that.
0x3f 5 hours ago
I think if you're going to use Rust on front end you're probably going to use it on back end too. In that case, I would just use Dioxus and get the e2e typing for free. What would be the benefit of Sycamore?
I wouldn't recommend e2e Rust generally yet though. I think server/API + web could work, but mobile is just boiling the ocean and will never be as good as native. You might think you can just use it for server/API + web, then do native mobile apps, but actually the escape hatches in all the frameworks I've used are not great.
Sad to say but "just use React" remains the good advice.
arpadav 6 hours ago
i've had my shot at sycamore a number of times. IMO leptos (leptos.dev) has far more fine-grained capabilities, and dioxus (dioxuslabs.com) is overall more hand-holdy but also powerful. comes with tradeoff for speed. wasm still isnt there yet (yet..) but a lot more web frameworks (including smaller rust ones) can be tracked here: https://krausest.github.io/js-framework-benchmark/current.ht...
eviks 5 hours ago
What is "next gen" about it, is it "just" fine-grained reactivity? Or is this opposed to prev gen of Rust web UI libs, which were...? Couldn't find it in the book quickly, and it seems to not even have search...
d0liver 4 hours ago
My impression was that it's next gen because it's using Rust on WASM as opposed to something that compiles to JavaScript.
However, I could be wrong. There's a small semantic difference between "next gen Rust web UI library" and "next gen web UI library written in Rust"
jtrueb 6 hours ago
Is there a new version or news related to this? v0.9 was Nov 2024, and Leptos and Dioxus have been a lot more active.
lukechu10 6 hours ago
There has been a few minor releases since. I am planning on making a new release soon with a few bug fixes and working on new major features.
I'm also looking for new contributors and maintainers!
conceptme 7 hours ago
a UI library needs some demo
lukechu10 7 hours ago
The website itself is made with Sycamore!
There are also a bunch of examples at https://github.com/sycamore-rs/sycamore/tree/main/examples
You can see the deployed versions at https://examples.sycamore.dev/<example name>/ for instance: https://examples.sycamore.dev/todomvc/
ecshafer 5 hours ago
The website is an entirely static website, and the frameworks main pitch is how good it is with reactive websites. This website could be entirely the same with html and css.
lukechu10 5 hours ago
catapart 6 hours ago
in case you don't understand what GP is suggesting: your website does not actually describe what you're providing. A "next generation Rust UI library powered by fine-grained reactivity." could mean a UI for native apps - something like egui or Dioxys - or it could mean a way to use rust to output HTML, CSS, and javascript. Or a bunch of other things. And, regardless, there's no way to look at your website and determine how to get that output using sycamore. I can inspect and see your HTML or your CSS, but there's no Rust code for me to compare that against without going and looking it up somewhere.
To be more succinct: you don't even have an image of your UI running on your websites landing page. Not one single image of the library which is, again, a UI library. People have an interest in knowing "does this look and feel like I want it to?" as well as "can I use this in the projects I'm working on?". Both of those questions should be answered by your landing page. For me, at least, it doesn't do that.
lukechu10 6 hours ago
silon42 7 hours ago
I get: Uncaught (in promise) ReferenceError: WebAssembly is not defined
lukechu10 6 hours ago
luckydata 3 hours ago
I will say it bluntly because it needs to be said: that website is not enough for anyone to be interested in the library.
lukechu10 2 hours ago
FrustratedMonky an hour ago
Every UI or GUI 'new fancy' package should include a very obvious Demo or link to Demo on the Home Page.
You're trying to sell me on some slick looking stuff -> Then Show It. Make it obvious. The market is crowded, people don't have time to hunt around and download it to try.
Don't make me read a manual before convincing me I should spend time on it.
luckydata 3 hours ago
Not a single example of an actual application is not a good look for a web ui library
lukechu10 2 hours ago
What kind of examples were you expecting? There are plenty of examples in the examples/ folder on GitHub as well as plenty of other projects using Sycamore as can be seen from GitHub’s reverse dependency page
0x457 2 hours ago
At very least I'd like to see how easy it is to build a simple -/+ counter and click some buttons.
I used Sycamore tho, it's neat.
lukechu10 2 hours ago
sourcegrift 7 hours ago
Looks very good and probably will be my library of choice for my next web project.
For desktop, I'm very happy with qmetaobject-rs. Qt is time tested and highly reliable. And gui is, frankly, serious business.
Also, Generally speaking, UI itself is best done declaratively rather than imperatively. There's a reason quick is adopted more than qwidgets.
silon42 6 hours ago
For simple stuff, qml is OK/better (except the JS part)... but for some more complicated views I'd want qwidgets.