recoil#AtomEffect TypeScript Examples

The following examples show how to use recoil#AtomEffect. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source File: index.ts    From recoil-persist with MIT License 4 votes vote down vote up 
recoilPersist = (
  config: PersistConfiguration = {},
): { persistAtom: AtomEffect<any> } => {
  if (typeof window === 'undefined') {
    return {
      persistAtom: () => {},
    }
  }

  const { key = 'recoil-persist', storage = localStorage } = config

  const persistAtom: AtomEffect<any> = ({ onSet, node, trigger, setSelf }) => {
    if (trigger === 'get') {
      const state = getState()
      if (typeof state.then === 'function') {
        state.then((s) => {
          if (s.hasOwnProperty(node.key)) {
            setSelf(s[node.key])
          }
        })
      }
      if (state.hasOwnProperty(node.key)) {
        setSelf(state[node.key])
      }
    }

    onSet(async (newValue, _, isReset) => {
      const state = getState()
      if (typeof state.then === 'function') {
        state.then((s: any) => updateState(newValue, s, node.key, isReset))
      } else {
        updateState(newValue, state, node.key, isReset)
      }
    })
  }

  const updateState = (
    newValue: any,
    state: any,
    key: string,
    isReset: boolean,
  ) => {
    if (isReset) {
      delete state[key]
    } else {
      state[key] = newValue
    }

    setState(state)
  }

  const getState = (): any => {
    const toParse = storage.getItem(key)
    if (toParse === null || toParse === undefined) {
      return {}
    }
    if (typeof toParse === 'string') {
      return parseState(toParse)
    }
    if (typeof toParse.then === 'function') {
      return toParse.then(parseState)
    }

    return {}
  }

  const parseState = (state: string) => {
    if (state === undefined) {
      return {}
    }
    try {
      return JSON.parse(state)
    } catch (e) {
      console.error(e)
      return {}
    }
  }

  const setState = (state: any): void => {
    try {
      if (typeof storage.mergeItem === 'function') {
        storage.mergeItem(key, JSON.stringify(state))
      } else {
        storage.setItem(key, JSON.stringify(state))
      }
    } catch (e) {
      console.error(e)
    }
  }

  return { persistAtom }
}