I've been deceiving you all. I had you believe that Svelte was a UI framework — unlike React and Vue etc, because it shifts work out of the client and into the compiler, but a framework nonetheless.
But that's not exactly accurate. In my defense, I didn't realise it myself until very recently. But with Svelte 3 around the corner, it's time to come clean about what Svelte really is.
Svelte is a language.
Specifically, Svelte is an attempt to answer a question that many people have asked, and a few have answered: what would it look like if we had a language for describing reactive user interfaces?
A few projects that have answered this question:
(Idyll is an outlier as it's geared towards a specific use case, rather than general purpose app development, but I think it qualifies as an example.)
These projects are all very cool, but there's a reason they haven't hit mass adoption: they want to control the entire world. You can't adopt Elm or Imba incrementally, and they need dedicated tooling far beyond just the compiler itself (e.g. syntax highlighting, unless you like your code monochrome). In some cases (Elm stands out), interop with the JS ecosystem is less than seamless.
Beyond that, they have a steep learning curve, which is hard to justify when there are so many options that are more accessible.
Thinking inside the box
- It would extend CSS by adding a scoping mechanism that kept styles from clobbering each other
How do we make reactivity a language primitive without introducing invalid syntax, or breaking the relationship with existing tooling (like TypeScript)? By hacking existing syntax:
- We instrument assignments to variables and properties
- We add
$:statements, using the little-known label construct, that run whenever their inputs change value
- We tie it all together with an opinionated scheduler
This, to me, is the best of all possible worlds: we can lean on decades of accumulated wisdom by extending well-known languages, author components in a delightfully concise and expressive way, and yet still generate apps that are bleeding-edge in terms of performance and everything that goes with it.
I just used svelte to convert a vue project and I had a great experience.
To reduce the "time to first professional delivery", this tech could use some additions :
-a simple built in solution for internationalization
-simple config option to make the styles unscoped and/or cascading to child instances
-support nested css rules
-lazy loading to further svelte advantage on bundle size
-configure the basic template with default json import support (rollup plugin / config)
-make the !production runtime variable easier to find and why not associate the alias feature of rollup with this doc/tuto to let users have some dev/prod variants.
These are subjective opinions after a specific task / context but I believe this situation is the most useful when gathering feedback for improvements.
Apart from that I can say that this experience was seamless even if I had previous experience with neither svelte nor vue.
I'm planning on using svelte very often, especially because I work on website customization and additional content which benefit from being bundled small and executing fast. Thanks for offering us this great tool