npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@jfdi/use-computed-state

v0.0.3

Published

A custom hook for holding complex, derived or computed state along with its source or simple state, which can even be just a timestamp for versioning a set of derived state.

Downloads

6

Readme

useComputedState

A custom hook for holding complex, derived or computed state along with its source or simple state, which can even be just a timestamp for versioning a set of derived state.

Why?

Because I've seen so many devs get tied up in knots trying to manage the complexities of computed or derived state in React. Synchronising everything becomes a nightmare. As complexity grows, you add more and more lines of code to try to prevent all those unwanted renders or render loops. Don't do that. Use this instead.

What's computed or derived state?

It's the bits of data you hold which are computed or derived from true state, or whose true state is actually held somewhere else. For example, a form maintains its own state, in its field values... duplicate it, and you have synchronisation problems. A backend database maintains the data you fetch from it... the only piece of true state you want to manage is probably the timestamp denoting when you last fetched that data. Updating backend data, particularly optimistically whilst immediately updating the UI, requires yet more synchronisation. This is why useComputedState exists.

Experienced devs normally get around this kind of problem in React by storing their computed or derived state in a ref using a useRef hook. That's exactly what this custom hook does. But it also abstracts away all the inner workings, giving you a nice clean API for doing this sort of thing as though it's just another piece of state but without the associated state update renders.

Usage

const { state, computedState, setState, setComputedState, notifyChange } = useComputedState({ initialState = Date.now(), initialComputedState, computeFn })

If all you pass to the hook is initialComputedState, state becomes a simple timestamp versioning that data. Of course you can pass initialState instead, and the hook will call your computeFn callback to compute or derive your computedState whenever you call setState. If all you want is to notify the hook that something in your computedState changed, just call notifyChange, or you can specify how to change the computedState using setComputedState.

Try It

Clone the repo, then...

pnpm i -r
pnpm start -r