Teaful

Tiny, easy and powerful React state management library

What advantages does it have? ✨

📦 ・Tiny: Less than 1kb package to manage your state in React and Preact.
🌱 ・Easy: You don't need actions, reducers, selectors, connect, providers, etc. Everything can be done in the simplest and most comfortable way.
🚀 ・Powerful: When a store property is updated, only its components are re-rendered. It's not re-rendering components that use other store properties.

Guide 🗺

1. Installation 🧑🏻‍💻
2. Init your store 👩🏽‍🎨
- createStore
- How to export
3. Manage the store 🕹
4. Register events after an update 🚦
5. How to... 🧑‍🎓
6. Teaful Devtools 🛠
7. Addons and extras 🌀
8. Examples 🖥
9. Roadmap 🛣
10. Contributors ✨

Installation 🧑🏻‍💻

yarn add teaful
# or
npm install teaful --save

Init your store 👩🏽‍🎨

Each store has to be created with the createStore function. This function returns all the methods that you can use to consume and update the store properties.

createStore

import createStore from "teaful";

const { useStore } = createStore();

Or also with an initial store:

const initialStore = {
  cart: { price: 0, items: [] },
};
const { useStore, getStore } = createStore(initialStore);

Or also with an event that is executed after every update:

const initialStore = {
  cart: { price: 0, items: [] },
};

function onAfterUpdate({ store, prevStore }) {
  console.log("This callback is executed after an update");
}

const { useStore } = createStore(initialStore, onAfterUpdate);

Input:

name	type	required	description
`initialStore`	`object<any>`	`false`	Object with your initial store.
`onAfterUpdate`	`function`	`false`	Function that is executed after each property change. More details.

Output:

name	type	description	example
`useStore`	`Proxy`	Proxy hook to consume and update store properties inside your components. Each time the value changes, the component is rendered again with the new value. More info.	`const [price, setPrice] = useStore.cart.price()`
`getStore`	`Proxy`	Similar to `useStore` but without subscription. You can use it as a helper outside (or inside) components. Note that if the value changes, it does not cause a rerender. More info.	`const [price, setPrice] = getStore.cart.price()`
`setStore`	`Proxy`	It's a proxy helper to modify a store property outside (or inside) components. More info.	`setStore.user.name('Aral')` or `setStore.cart.price(price => price + 10)`
`withStore`	`Proxy`	HoC with `useStore` inside. Useful for components that are not functional. More info.	`withStore.cart.price(MyComponent)`

How to export

We recommend using this type of export:

// ✅
export const { useStore, getStore, withStore } = createStore({
  cart: { price: 0, items: [] },
});

This way you can import it with:

// ✅
import { useStore } from '../store'

Avoid using a default export with all:

// ❌
export default createStore({ cart: { price: 0, items: [] } });

Because then you won't be able to do this:

// ❌  It's not working well with proxies
import { useStore } from '../store'

Manage the store 🕹

useStore hook

It's recommended to use the useStore hook as a proxy to indicate exactly what portion of the store you want. This way you only subscribe to this part of the store avoiding unnecessary re-renders.

import createStore from "teaful";

const { useStore } = createStore({
  username: "Aral",
  count: 0,
  age: 31,
  cart: {
    price: 0,
    items: [],
  },
});

function Example() {
  const [username, setUsername] = useStore.username();
  const [cartPrice, setCartPrice] = useStore.cart.price();

  return (
    <>
      <button onClick={() => setUsername("AnotherUserName")}>
        Update {username}
      </button>
      <button onClick={() => setCartPrice((v) => v + 1)}>
        Increment price: {cartPrice}€
      </button>
    </>
  );
}

However, it's also possible to use the useStore hook to use all the store.

function Example() {
  const [store, setStore] = useStore();

  return (
    <>
      <button
        onClick={() =>
          setStore((s) => ({
            ...s,
            username: "AnotherUserName",
          }))
        }
      >
        Update {store.username}
      </button>
      <button
        onClick={() =>
          setStore((s) => ({
            ...s,
            cart: { ...s.cart, price: s.cart.price + 1 },
          }))
        }
      >
        Increment price: {store.cart.price}€
      </button>
    </>
  );
}

Input:

name	type	description	example
Initial value	`any`	This parameter is not mandatory. It only makes sense for new store properties that have not been defined before within the `createStore`. If the value has already been initialized inside the `createStore` this parameter has no effect.	`const [price, setPrice] = useStore.cart.price(0)`
event after an update	`function`	This parameter is not mandatory. Adds an event that is executed every time there is a change inside the indicated store portion.	`const [price, setPrice] = useStore.cart.price(0, onAfterUpdate)` And the function: `function onAfterUpdate({ store, prevStore }){ console.log({ store, prevStore }) }`

Output:

Is an Array with 2 items:

name	type	description	example
value	`any`	The value of the store portion indicated with the proxy.	A store portion `const [price] = useStore.cart.price()` All store: `const [store] = useStore()`
update value	`function`	Function to update the store property indicated with the proxy.	Updating a store portion: `const [count, setCount] = useStore.count(0)` Way 1: `setCount(count + 1)` Way 1: `setCount(c => c + 1)` ------- Updating all store: `const [store, updateStore] = useStore()` Way 1: `updateStore({ ...store, count: 2 }))` Way 1: `updateStore(s => ({ ...s, count: 2 }))`

setStore helper

Useful helper to modify the store from anywhere (outside/inside components).

Example:

const initialStore = { count: 0, name: 'Aral' }
const { setStore } = createStore(initialStore);

const resetStore = () => setStore(initialStore);
const resetCount = () => setStore.count(initialStore.count);
const resetName = () => setStore.name(initialStore.name);

// Component without any re-render (without useStore hook)
function Resets() {
  return (
    <>
      <button onClick={resetStore}>
        Reset store
      </button>
      <button onClick={resetCount}>
        Reset count
      </button>
      <button onClick={resetName}>
        Reset name
      </button>
    </>
  );
}

Another example:

const { useStore, setStore } = createStore({
  firstName: '',
  lastName: '' 
});

function ExampleOfForm() {
  const [formFields] = useStore()

  return Object.entries(formFields).map(([key, value]) => (
    <input 
      defaultValue={value} 
      type="text"
      key={key}
      onChange={e => {
        // Update depending the key attribute
        setStore[key](e.target.value)
      }} 
    />
  ))
}

This second example only causes re-renders in the components that consume the property that has been modified.

In this way:

const [formFields, setFormFields] = useStore()
// ...
setFormFields(s => ({ ...s, [key]: e.target.value })) // ❌

This causes a re-render on all components that are consuming any of the form properties, instead of just the one that has been updated. So using the setStore proxy helper is more recommended.

getStore helper

It works exactly like useStore but with some differences:

It does not make a subscription. So it is no longer a hook and you can use it as a helper wherever you want.

It's not possible to register events that are executed after a change.

getStore.cart.price(0, onAfterPriceChange); // ❌

function onAfterPriceChange({ store, prevStore }) {
  // ...
}

If the intention is to register events that last forever, it has to be done within the createStore:

const { getStore } = createStore(initialStore, onAfterUpdate); // ✅

function onAfterUpdate({ store, prevStore }) {
  // ..
}

Very useful to use it:

Outside components: helpers, services, etc.
Inside components: Avoiding rerenders if you want to consume it inside events, when you only use the updater const [, setCount] = getStore.count(), etc.

Example:

import { useState } from "react";

const initialStore = { count: 0 }
const { getStore } = createStore(initialStore);

function Example1() {
  return (
    <button onClick={() => {
      const [, setStore] = getStore();
      setStore(initialStore)
    }}>
      Reset store
    </button>
  );
}

function Example2() {
  const [newCount, setNewCount] = useState();

  function saveIncreasedCount(e) {
    e.preventDefault();
    const [count, setCount] = getStore.count();
    if (newCount > count) setCount(newCount);
    else alert("You should increase the value");
  }

  return (
    <form onSubmit={saveIncreasedCount}>
      <input
        value={newCount}
        onChange={(e) => setNewCount(e.target.valueAsNumber)}
        type="number"
      />
      <button>Save the increased count value</button>
    </form>
  );
}

withStore HoC

It's a wrapper of the useStore for non-functional components. Where you receive the same thing that the useStore hook returns inside this.props.store.

Example with a store portion:

const { withStore } = createStore();

class Counter extends Component {
  render() {
    const [count, setCount] = this.props.store;
    return (
      <div>
        <h1>{count}</h1>
        <button onClick={() => setCount((v) => v + 1)}>+</button>
        <button onClick={() => setCount((v) => v - 1)}>-</button>
        <button onClick={() => setCount(0)}>reset</button>
      </div>
    );
  }
}

// Similar to useStore.counter.count(0)
const CounterWithStore = withStore.counter.count(Counter, 0);

Example with all store:

const { withStore } = createStore({ count: 0 });

class Counter extends Component {
  render() {
    const [store, setStore] = this.props.store;
    return (
      <div>
        <h1>{store.count}</h1>
        <button onClick={() => setStore({ count: store.count + 1 })}>+</button>
        <button onClick={() => setStore({ count: store.count - 1 })}>-</button>
        <button onClick={() => setStore({ count: 0 })}>reset</button>
      </div>
    );
  }
}

// Similar to useStore()
const CounterWithStore = withStore(Counter);

The only difference with the useStore is that instead of having 2 parameters (initialValue, onAfterUpdate), it has 3 where the first one is mandatory and the other 2 are not (Component, initialValue, onAfterUpdate).

Register events after an update 🚦

It is possible to register an event after each update. This can be useful for validating properties, storing error messages, optimistic updates...

There are 2 ways to register:

Permanent events: Inside createStore. This event will always be executed for each change made within the store.

export const { useStore, getStore } = createStore(
  initialStore,
  onAfterUpdate
);

function onAfterUpdate({ store, prevStore }) {
  // Add an error msg
  if (store.count > 99 && !store.errorMsg) {
    const [, setErrorMsg] = getStore.errorMsg();
    setErrorMsg("The count value should be lower than 100");
    return;
  }
  // Remove error msg
  if (store.count <= 99 && store.errorMsg) {
    const [, setErrorMsg] = getStore.errorMsg();
    setErrorMsg();
  }
}

Temporal events: Inside useStore / withStore. These events will be executed for each change in the store (or indicated portion) only during the life of the component, when the component is unmounted the event is removed.

function Count() {
  const [count, setCount] = useStore.count(0, onAfterUpdate);
  const [errorMsg, setErrorMsg] = useStore.errorMsg();

  // The event lasts as long as this component lives
  function onAfterUpdate({ store, prevStore }) {
    // Add an error msg
    if (store.count > 99 && !store.errorMsg) {
      setErrorMsg("The count value should be lower than 100");
      return;
    }
    // Remove error msg
    if (store.count >= 99 && store.errorMsg) {
      setErrorMsg();
    }
  }

  return (
    <>
      {errorMsg && <div className="erorMsg">{errorMsg}</div>}
      <div className="count">{count}</div>
      <button onClick={() => setCount((v) => v + 1)}>Increment</button>
    </>
  );
}

How to... 🧑‍🎓

Add a new store property

You can use useStore / getStore / withStore even if the property does not exist inside the store, and create it on the fly.

const { useStore } = createStore({ username: "Aral" });

function CreateProperty() {
  const [price, setPrice] = useStore.cart.price(0); // 0 as initial value

  return <div>Price: {price}</div>;
}

function OtherComponent() {
  // store now is { username: 'Aral', cart: { price: 0 } }
  const [store] = useStore();
  console.log(store.cart.price); // 0
  // ...
}

It's not mandatory to indicate the initial value, you can create the property in a following step with the updater.

const { useStore } = createStore({ username: "Aral" });

function CreateProperty() {
  const [cart, setCart] = useStore.cart();

  useEffect(() => {
    initCart();
  }, []);
  async function initCart() {
    const newCart = await fetch("/api/cart");
    setCart(newCart);
  }

  if (!cart) return null;

  return <div>Price: {cart.price}</div>;
}

Use more than one store

You can have as many stores as you want. The only thing you have to do is to use as many createStore as stores you want.

store.js

import createStore from "teaful";

export const { useStore: useCart } = createStore({ price: 0, items: [] });
export const { useStore: useCounter } = createStore({ count: 0 });

Cart.js

import { useCart } from "./store";

export default function Cart() {
  const [price, setPrice] = useCart.price();
  // ... rest
}

Counter.js

import { useCounter } from "./store";

export default function Counter() {
  const [count, setCount] = useCounter.count();
  // ... rest
}

Update several portions avoiding rerenders in the rest

If you do this it causes a rerender to all the properties of the store:

// 😡
const [store, setStore] = useStore();
setStore({ ...store, count: 10, username: "" });

And if you do the next, you convert the whole store into only 2 properties ({ count: 10, username: '' }), and you will remove the rest:

// 🥵
const [store, setStore] = useStore();
setStore({ count: 10, username: "" });

If you have to update several properties and you don't want to disturb the rest of the components that are using other store properties you can create a helper with getStore.

export const { useStore, setStore } = createStore(initialStore);

export function setFragmentedStore(fields) {
  Object.entries(fields).forEach(([key, value]) => {
    setStore[key](value);
  });
}

And use it wherever you want:

// 🤩
import { setFragmentedStore } from "./store";

// ...
setFragmentedStore({ count: 10, username: "" });

Define calculated properties

It's possible to use the setStore together with the function that is executed after each update to have store properties calculated from others.

In this example the cart price value will always be a value calculated according to the array of items:

export const { useStore, setStore } = createStore(
  {
    cart: {
      price: 0,
      items: [],
    },
  },
  onAfterUpdate
);

function onAfterUpdate({ store }) {
  const { items, price } = store.cart;
  const calculatedPrice = items.length * 3;

  // Price always will be items.length * 3
  if (price !== calculatedPrice) {
    setStore.cart.price(calculatedPrice);
  }
}

It's an anti-pattern? Not in Teaful 😊. As only the fragments of the store are updated and not the whole store, it is the same as updating both properties (cart.items and cart.price) instead of just cart.items. The anti-pattern comes when it causes unnecessary rerenders, but this is not the case. Only the components that use cart.items and cart.price are rerendered and not the others.

Teaful Devtools 🛠

To debug your stores, you can use Teaful DevTools.

Addons and extras 🌀

To facilitate the creation of libraries that extend Teaful (such as teaful-devtools), we allow the possibility to add an extra that:

Have access to everything returned by each createStore consumed: getStore, useStore, withStore.
Return an object with new elements to be returned by each createStore. It's optional, if nothing is returned it will continue to return the usual. If, for example, you return { getCustomThing } will do an assign with what is currently returned by the createStore.
Ability to subscribe, unsubscribe and notify in each createStore.

For that, use the createStore.ext function.

teaful-yourlib:

import createStore from 'teaful'

createStore.ext(({ getStore,  }, subscription) => {
    // s = subscribe (minified by Teaful)
    //     "." -> all store
    //     ".cart" -> only inside cart
    //     ".cart.price" -> only inside cart.price
    // n = notify (minified by Teaful)
    // u = unsubscribe (minified by Teaful)
    subscription.s(".", ({ store, prevStore }) => {
      // This will be executed in any store (".") change.
    });

    // optional
    return { getCustomThing: () => console.log('example') }
})

Then, your library should be imported at the top:

import 'teaful-yourlib'
import { render } from 'preact';
import App from './components/App';

render(<App />, document.getElementById('root'));

Examples 🖥

We will expand the examples over time. For now you can use this Codesandbox:

Roadmap 🛣

For 1.0:

React support
Teaful DevTools
TypeScript types support
Migrate full Teaful project to TypeScript
React Native support
Vanilla JavaScript support
Create a documentation website
Add more examples: with Next.js, Remix, Preact, React Native...

Optional for 1.0 (else +1.0):

Svelte support
Vue support
Solid support

If you think that there is something that should be preindicated by version 1.0 please report it as an issue or discussion 🙏

Contributors ✨

Thanks goes to these wonderful people (emoji key):

_{Aral Roca Gomez} 🚧 💻	_{Danielo Artola} 🚇 💻	_{Yuki Shindo} 🚇	_{YONGJAE LEE(이용재)} 🐛	_niexq 📖 🚇	_nekonako 📖	_Shubham 📖
_{Siddharth Borderwala} 📖 🚇 💻	_watcher 💻	_{Philippe Schommers} 💻	_ktdd 📖