React Mut

🔗 Subscribe component to any object.

Click here to see sandbox.

Basics

Subscribe with useMut → Mutate object → Notify subscribers with mut

import { mut, useMut } from 'react-mut';

const mutableObject = { title: 'title' };

const Component = () => {
  // subscribe
  useMut(mutableObject);

  return (
    <button
      onClick={() => {
        // mutate and notify subscribers
        mut(mutableObject).title = 'next title';
      }}
    >
      {mutableObject.title}
    </button>
  );
};

Mutations

You can mark objects as mutated with mut. You can call mut anytime (before mutation and after mutation).

import { mut } from 'react-mut';

const mutableObject = { title: 'title' };

// before mutation:
mut(mutableObject).title = 'next title';

// or after mutation:
mutableObject.title = 'next title';
mut(mutableObject);

// this will work too:
Object.assign(mut(mutableObject), {
  title: 'next title',
});

Notifying subscribers scheduled via microtask. But you can immediately notify subscribers with sync. It can be useful for tests, for example.

import { sync } from 'react-mut';

const mutableObject = { title: 'title' };

const action = () => {
  mut(mutableObject).title = 'next title';

  // immediately notify subscribers
  sync();
};

Versions

When you call mut with object, object's version updated. You can read object's version with ver. It can be useful for hook's dependencies, for example.

import { mut, useMut } from 'react-mut';

const mutableObject = { title: 'title' };

const Component = () => {
  useMut(mutableObject);

  useEffect(() => {
    // Will be logged on button below click
    console.log(mutableObject);
  }, [ver(mutableObject)]);

  return (
    <button
      onClick={() => {
        mut(mutableObject).title = 'next title';
      }}
    >
      {mutableObject.title}
    </button>
  );
};

Subscriptions

You can subscribe to object with sub. You can unsubscribe from object with returned callback.

import { sub, mut } from 'react-mut';

const mutableObject = { title: 'title' };

const unsubscribe = sub(mutableObject, () => {
  // will be logged on mutableObject's version change.
  console.log(mutableObject);
});

unsubscribe();

You also can unsubscribe from object with unsub. You can unsubscribe all from object with unsub without callback.

import { unsub, sub, mut } from 'react-mut';

const mutableObject = { title: 'title' };

const callback = () => {
  // will be logged on mutableObject's version change.
  console.log(mutableObject);
};

// subscribe callback to mutableObject
sub(mutableObject, callback);

// unsubscribe callback from mutableObject
unsub(mutableObject, callback);

// subscribe anonymus callback to mutableObject
sub(mutableObject, () => {
  console.log(mutableObject);
});
// unsubscribe all callbacks from mutableObject
unsub(mutableObject);

Hooks

You can use useMut to subscribe component to object. Component will be re-rendered after mut call with object.

import { mut, useMut } from 'react-mut';

const mutableObject = { title: 'title' };

// Will be re-rendered on mutableObject's version change
const Component = () => {
  const mutableObject = useMut(mutableObject);

  return <div>{mutableObject.title}</div>;
};

// Will be re-rendered on mutableObject.title change
const AnotherComponent = () => {
    const title = useMut(mutableObject, () => title);

    return <div>{title}</div>;
};

You can use selectors with useSel to optimize re-renders. Selector will be called after mut call with any object. Component will be re-rendered if selected value changed.

import { mut, useSel } from 'react-mut';

const mutableObject = { title: 'title' };

// Will be re-rendered on mutableObject.title change
const Component = () => {
  const title = useSel(() => mutableObject.title);

  return <div>{title}</div>;
};

Also, you can use useMutSel for subscribing to nested mutable objects. Selector will be called after mut call with any object. It's alias for useMut(useSel(...));

import { mut, useMutSel } from 'react-mut';

const items = [{ title: 'title' }];

// Will be re-rendered on items[0]'s version change
const Component = () => {
  const item = useMutSel(() => items[0]);

  return <div>{item.title}</div>;
};