mini-store
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[](https://travis-ci.org/yesmeck/mini-store)
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# mini-store
[](https://travis-ci.org/yesmeck/mini-store)
A state store for React component.
## Motivation
When you want to share a component's state to another one, a commom pattern in React world is [lifting state up](https://reactjs.org/docs/lifting-state-up.html#lifting-state-up). But one problem of this pattern is performance, assume we have a component in following hierarchy:
```javascript
<Parent>
<ChildA />
<ChildB />
<ChildC />
</Parent>
```
`ChildA` want to share state with `ChildB`, so you lifting `ChildA`'s state up to `Parent`. Now, when `ChildA`'s state changes, the whole `Parent` will rerender, includes `ChildC` which should not happen.
Redux do a good job at this situation throgh keeping all state in store, then component can subscribe state's changes, and only connected components will rerender. But `redux` + `react-redux` is overkill when you are writing a component library. So I wrote this little library, It's like Redux's store without "reducer" and "dispatch".
## Example
[See this demo online.](https://codesandbox.io/s/mq6223x08p)
```javascript
import { Provider, create, connect } from 'mini-store';
class Counter extends React.Component {
constructor(props) {
super(props);
this.store = create({
count: 0,
});
}
render() {
return (
<Provider store={this.store}>
<div>
<Buttons />
<Result />
</div>
</Provider>
)
}
}
@connect()
class Buttons extends React.Component {
handleClick = (step) => () => {
const { store } = this.props;
const { count } = store.getState();
store.setState({ count: count + step });
}
render() {
return (
<div>
<button onClick={this.handleClick(1)}>+</button>
<button onClick={this.handleClick(-1)}>-</button>
</div>
);
}
}
@connect((state) => ({ count: state.count }))
class Result extends React.Component {
render() {
return (
<div>{this.props.count}</div>
);
};
}
```
## API
### `create(initialState)`
Creates a store that holds the state. `initialState` is plain object.
### `<Provider store>`
Makes the store available to the connect() calls in the component hierarchy below.
### `connect(mapStateToProps)`
Connects a React component to the store. It works like Redux's `connect`, but only accept `mapStateToProps`. The connected component also receive `store` as a prop, you can call `setState` directly on store.
## License
MIT