setupListeners

一个用于启用 refetchOnFocus 和 refetchOnReconnect 行为的实用程序。它需要来自您的存储的 dispatch 方法。调用 setupListeners(store.dispatch) 将使用推荐的默认值配置监听器，但您可以选择提供回调以进行更细粒度的控制。

setupListeners 默认配置

let initialized = false
export function setupListeners(
  dispatch: ThunkDispatch<any, any, any>,
  customHandler?: (
    dispatch: ThunkDispatch<any, any, any>,
    actions: {
      onFocus: typeof onFocus
      onFocusLost: typeof onFocusLost
      onOnline: typeof onOnline
      onOffline: typeof onOffline
    },
  ) => () => void,
) {
  function defaultHandler() {
    const handleFocus = () => dispatch(onFocus())
    const handleFocusLost = () => dispatch(onFocusLost())
    const handleOnline = () => dispatch(onOnline())
    const handleOffline = () => dispatch(onOffline())
    const handleVisibilityChange = () => {
      if (window.document.visibilityState === 'visible') {
        handleFocus()
      } else {
        handleFocusLost()
      }
    }

    if (!initialized) {
      if (typeof window !== 'undefined' && window.addEventListener) {
        // Handle focus events
        window.addEventListener(
          'visibilitychange',
          handleVisibilityChange,
          false,
        )
        window.addEventListener('focus', handleFocus, false)

        // Handle connection events
        window.addEventListener('online', handleOnline, false)
        window.addEventListener('offline', handleOffline, false)
        initialized = true
      }
    }
    const unsubscribe = () => {
      window.removeEventListener('focus', handleFocus)
      window.removeEventListener('visibilitychange', handleVisibilityChange)
      window.removeEventListener('online', handleOnline)
      window.removeEventListener('offline', handleOffline)
      initialized = false
    }
    return unsubscribe
  }

  return customHandler
    ? customHandler(dispatch, { onFocus, onFocusLost, onOffline, onOnline })
    : defaultHandler()
}

如果您注意到，onFocus、onFocusLost、onOffline、onOnline 都是提供给回调的 action。此外，这些 action 可用于 api.internalActions，并且可以通过以下方式进行调度

手动 onFocus 事件

dispatch(api.internalActions.onFocus())