iom

• What
• Why
• How
  • A Quick Example
    • 1. Let’s create a new store…
    • 2. And subscribe to the store…
    • 3. And update the state…
    • 4. And clean up
    • 5. Then read the docs!
  • Usage with React
  • Purity and Stack Safety
    • Purity
    • Stack Safety

What

iom is Esperanto for “a little” 😉

Tiny, simple, over-powered state management

Why

It’s a good question — why did I need to roll my own state management library?

First of all, I didn’t need to and other options may very well better suit your needs

But, since you asked:

• 🐣 it’s tiny (~⅕kB last time I checked)
• 🔤 it’s simple (one class whose instances surface only two methods)
• 🚀 it’s op af (caveat being that there’s no hand-holding whatsoever)

How

A Quick Example

If you’re wondering how state management can be over-powered…

1. Let’s create a new store…

Import iom

import Store from 'iom';

Describe the initial state… may as well save it somewhere, right?

const INITIAL_STATE = { on: false };

Create the store by passing the initial state into the constructor

const store = new Store(INITIAL_STATE);

Now you have a store

2. And subscribe to the store…

We’ll just send state updates to the console for now

const subscriber = console.log;

Passing a subscriber to the store returns a function which cancels the subscription… let’s hang onto that

const cancel = store.subscribe(subscriber);
// => { on: false }

All subscribers receive the current state when added to the store

3. And update the state…

This is where iom likely diverges from state managers you’ve used before

You may notice that we haven’t talked at all about updating state yet

That’s because you can update state in anyway that you like at any point because actions are simply functions passed to the store which take the current state as their argument and return the new state

So let’s create an action

const toggleOn = state => ({ ...state, on: !state.on });

And perform an update

store.update(toggleOn);
// => { on: true }

And that’s iom!

4. And clean up

You can add and remove subscribers at any point

So let’s cancel our subscription now that we’re done

cancel();

5. Then read the docs!

Usage with React

Purity and Stack Safety

Purity and stack safety are up to you

Purity

If you’re using a mutable data structure for your state, be mindful and don’t mutate it

Stack Safety

Don’t call actions from within subscribers or other actions or you are very likely to encounter infinite loops

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iom is MIT licensed.