Solidjs – JavaScript UI Library

Wow, I just read about Solid for the first time, and I'm impressed at the API design. I love how it's a fully reactive data flow thing, but it looks and feels like React Hooks.

The other reactive/observable-based frameworks I've seen (eg Cycle) put the observable streams center piece. I always felt that was distracting, and that nuances about how the underlying observable stream library worked (eg Rxjs or Bacon) quickly got in the way.

Solid still puts the components firmly at the center, just like React, but replaces React's state concept by reactive observable state, called "signals". You use them like you useState in React, but deep inside it's an observable stream of data changes, and you get all the finegrained update control that comes with that.

I also love how noun-heavy it is. Resources, tracking scopes, effects, signals. It's just like how React moved from "do this thing after the component updated" to "ok we have this concept called an effect", but extended to more topics such as dealing with async data loading, when exactly a signal is observable, etc.

What is interesting, render function really is a function factory - like reagent form-2. That let you simplify "hooks rules", because they're called once and also let you factor your components more easily without much consideration for cost of the component abstraction.

My favourite feature is "opt-in" reactivity. In bigger data visualisations you must be conscious what would re-render in response to what change. If you have only component boundaries like in React it is very easy to waste re-renders and then you start adding useMemos and React.lazy. In Solid I can start from opposite side, and declare granular computed properties and Solid will take care of all re-renders.

It has few rough edges like special props object or "boilerplate" function calls. But that's some minor ergonomic issues.

In conclusion, thanks Ryan!