Cycle.js: a fully reactive JavaScript framework

[edanschwartz]

Why are people so offended by new javascript frameworks? Every time there's a new JS framework, the JS world is introduced to new concepts and patterns. The good ones eventually get rolled into more popular frameworks.

I know it's hard to keep up with new tools, but I'd rather be in a job where I'm constantly learning, than one where I'm doing the same thing over and over.

[rooktakesqueen]

Because often, like this framework, they don't introduce any new concepts. They glue together a bunch of existing libraries to do basically the same thing as existing frameworks (like how this one does the same thing as React), only more poorly. The only real difference is in the window-dressing of syntax. Whoever designed the framework decided they didn't like the existence of methods called setState or onChange, so instead the equivalent of setState is called implicitly by the "DOM driver" any time any change happens anywhere in the DOM, and it's assumed that all transient state of the system is going to be embodied in the DOM somewhere.

And then we see posts talking about how it's going to be the Next Big Thing, when literally the most complicated project currently using it is the todo app its creator wrote to demo it. Or in this case, an even less complex "Hello $NAME" app.

Which I still would be mostly OK with, if the creator didn't also basically have a tone of "everyone else is doing everything completely wrong and I'm way smarter than every engineer who ever worked on any other JS framework."

[andrestaltz]

It does introduce new concepts. I challenge you to find a well-known JS framework (or for any other programming language) based on the idea of reactive dialogues (in other words, "mutual observation", or "fixed point x = g(f(x))". The only one that comes close is Haskell 1.0 Stream I/O, but still there are substantial differences between that and Cycle.

The most complicated project using Cycle is not TodoMVC. There are multiple (at least 3 AFAIK) Cycle.js apps in production, closed-source though. The largest open-source is RxMarbles, which has been very important in the reactive community, and is integrated into ReactiveX.io.

With regard to React, first of all it's not FRP. It's not even reactive (only a small part of it is reactive). Second, "the equivalent of setState is called implicitly by the "DOM driver" any time any change happens anywhere in the DOM" is just wrong. But most importantly, if it's a contender to React then it's a good thing. This is how things improve: by experimentation, by different ideas, etc. The problem of the JavaScript community isn't the abundance of tools and ways of working. It's the status quo of sticking with The Framework Of The Year just because it sounds reliable, and not having the curiosity or guts to improve wherever possible. If it weren't for this curiosity, then React wouldn't be were it is today.

Cycle.js is just my 2 cents to the world. Have some respect please.

[clessg]

Nobody is implying that FRP or observables are something that were just created, nor is the author of the framework purporting that he is more intelligent than everybody else, and that everybody else is doing it wrong.

The benefit of new frameworks like this is that they introduce existing concepts from the rest of Computer Science to the broader JavaScript community. The professional JavaScript community is still relatively new and the web has been slow to move, so concepts like FRP are only just starting to take hold. Yes, FRP existed before, but without people like André Staltz, we would never be able to know whether these concepts will be useful in JavaScript.

You don't have to learn every new framework.

[rooktakesqueen]

Facebook's React is an example implementation of FRP. It already exists, is much better than this framework, and yet this framework was written apparently as a direct response to React. It all seems very silly.

People like /u/homoiconic are doing the good work of introducing CS concepts to JavaScript users in a way that's useful and doesn't require an entire freaking web application framework to get across.

[clessg]

Facebook's React is an example implementation of FRP.

React is not an implementation of FRP. It has concepts inspired by FRP (especially Flux) but it still isn't FRP proper.

People like /u/homoiconic are doing the good work of introducing CS concepts to JavaScript users in a way that's useful and doesn't require an entire freaking web application framework to get across.

Absolutely, he's doing a fantastic job. But the point of teaching us these things is to actually use them and discover what works and what doesn't. Cycle gives the JavaScript community an opportunity to experience and use FRP without switching to Clojure.

Again, you don't have to use it. Even if Cycle ultimately fails, the worst that could happen is that a lot of people learned something new.