react-one

A single store, single action, global state management system for React apps.

installation

npm install react-one --save

or

yarn add react-one

Usage

import { Provider, connect } from 'react-one';

Wrap the root of your app with the Provider component and pass it an initialState object.

const INITIAL_STATE = { num: 0 };
...
render() {
  return (
    <Provider
      initialState={INITIAL_STATE}
      onSetState={newState => console.log('newState', newState)}
      >
      <App />
    </Provider>
  );
}

Connect any of your app's child components to the global store with the connect higher order component. Any connected component will have state and setState passed as props. Treat them as a global this.state and this.setState. This means you can call setState in one component and have that update reflected in another connected component without prop drilling or callbacks. This also means the global state will persist even when a connected component is unmounted.

class Example extends React.Component {
  render() {
    let { state, setState } = this.props;
    return (
      <>
        <button onClick={() => setState({ num: Math.random() })} />
        <h1>{state.num}</h1>
      </>
    );
  }
}

export default connect(Example);

If you want to call multiple setStates that rely on the previous state in the same block of code, you will probably have to use a callback or functional setState because setState, like this.setState, updates state asynchronously.

// this one line is equivalent
setState({ num: state.num + 1 }, newState => setState({ num: newState.num + 1 })); // state.num = 2
// to these two
setState(prevState => ({ num: prevState.num + 1 }));
setState(prevState => ({ num: prevState.num + 1 }));  // state.num = 2

// this won't work
setState({ num: state.num + 1 });
setState({ num: state.num + 1 }); // state.num = 1

// this is an exception
setState({ num: ++state.num });
setState({ num: ++state.num }); // state.num = 2

Example

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider, connect } from 'react-one';

const INITIAL_STATE = { num: 0 };

class App extends React.Component {
  render() {
    return (
      <Provider
        initialState={INITIAL_STATE}
        onSetState={newState => console.log('newState', newState)}
        >
        <div>
          <Buttons />
          <Num />
        </div>
      </Provider>
    );
  }
}

class Buttons extends React.Component {
  render() {
    let { state, setState } = this.props;
    return (
      <div>
        <button onClick={() => setState({ num: ++state.num })}>+</button>
        <button onClick={() => setState({ num: --state.num })}>-</button>
      </div>
    );
  }
}

Buttons = connect(Buttons); // if this were in another file, export default connect(Buttons)

class Num extends React.Component {
  render() {
    let { state } = this.props;
    return <h1>{state.num}</h1>;
  }
}

Num = connect(Num); // if this were in another file, export default connect(Num)

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

Running the example

git clone https://github.com/MiLeung/react-one.git

cd react-one

npm i

npm start

Then in another window

cd react-one/example

npm i

npm start