README.md

umi-plugin-recoil

A plugin for umijs@3.x to help you set RecoilRoot.

What is Recoil?

Recoil provides a fast and flexible way to share state across components with React Hooks Api.

What does this plugin do?

• Inject RecoilRoot to umi root container. So you can use useRecoilState in your code without declaring a RecoilRoot context.
• Provide an useRecoilObjState Api which can shallow merge your object-type state when calling setState.
• list-type state operator
• history-travel state operator
• RecoilRoot options

How to use?

Install dependencies with npm or yarn in you umijs@3 project

npm install umi-plugin-recoil recoil
# or
yarn add umi-plugin-recoil recoil

Create Recoil Atom in the right place

I am used to place the Atom inside 'recoil' folder like this.

Create Atom

Use atom to create a store that can be shared across your project.

import { atom } from 'recoil';

const myState = atom({
  key: 'myState',
  default: 'val',
});

export default myState;

You can also create an object-type Atom.

import { atom } from 'recoil';

const myObjState = atom({
  key: 'myObjState',
  default: {
    name: 'this is an object',
    value: 123,
  },
});

export default myState;

See more

Use state in your code

Use useRecoilState like useState to implicitly subscribe the component to the given state.

import React from 'react';
import { useRecoilState } from 'recoil';
import myState from '@/recoil/myState';

export default () => {
  const [state, setState] = useRecoilState(myState);

  return (
    <div>
      <div>{state}</div>
      <button
        onClick={() => {
          setState('clicked');
        }}
      >
        Click
      </button>
    </div>
  );
};

See more

[Special] Merge object-type state when setState

This plugin provides an useRecoilObjState Api which allow you subscribe an object-type atom and shallow merge the object when calling setState.

You should import the useRecoilObjState Api from umi;

import React from 'react';
import { useRecoilObjState } from 'umi'; // import from umi
import myObjState from '@/recoil/myObjState'; // see above

export default () => {
  const [objState, setObjState] = useRecoilObjState(myObjState);

  return (
    <div>
      <div>{objState.name}</div>
      <div>{objState.value}</div>
      <button
        onClick={() => {
          // objState will change to { name: 'this is an object', value: 888 } ;
          setObjState({
            value: 888,
          });
        }}
      >
        Click
      </button>
    </div>
  );
};