API

const { data, error, isLoading, isValidating, mutate } = useSWR(key, fetcher, options)

参数

¥Parameters

• key：请求的唯一键字符串（或函数/数组/空）（详情）、（高级用法）

  ¥key: a unique key string for the request (or a function / array / null) (details), (advanced usage)

• fetcher：（可选）一个 Promise 返回函数来获取你的数据 （详情）

  ¥fetcher: (optional) a Promise-returning function to fetch your data (details)

• options：（可选）此 SWR 钩子的选项对象

  ¥options: (optional) an object of options for this SWR hook

返回值

¥Return Values

• data：由 fetcher 解析的给定键的数据（如果未加载则为未定义）

  ¥data: data for the given key resolved by fetcher (or undefined if not loaded)

• error：fetcher 抛出的错误（或未定义）

  ¥error: error thrown by fetcher (or undefined)

• isLoading：如果有正在进行的请求并且没有 "加载的数据"。回退数据和之前的数据不被考虑 "加载的数据"

  ¥isLoading: if there's an ongoing request and no "loaded data". Fallback data and previous data are not considered "loaded data"

• isValidating：如果有请求或重新验证加载

  ¥isValidating: if there's a request or revalidation loading

• mutate(data?, options?)：改变缓存数据 （详情） 的函数

  ¥mutate(data?, options?): function to mutate the cached data (details)

更多信息可参见 此处。

¥More information can be found here.

选项

¥Options

• suspense = false：启用 React Suspense 模式 （详情）

  ¥suspense = false: enable React Suspense mode (details)

• fetcher(args)：获取器函数

  ¥fetcher(args): the fetcher function

• revalidateIfStale = true：即使存在旧数据也会自动重新验证 （详情）

  ¥revalidateIfStale = true: automatically revalidate even if there is stale data (details)

• revalidateOnMount：安装组件时启用或禁用自动重新验证 （详情）

  ¥revalidateOnMount: enable or disable automatic revalidation when component is mounted (details)

• revalidateOnFocus = true：当窗口获得焦点时自动重新验证 （详情）

  ¥revalidateOnFocus = true: automatically revalidate when window gets focused (details)

• revalidateOnReconnect = true：当浏览器重新获得网络连接时自动重新验证（通过 navigator.onLine）（详情）

  ¥revalidateOnReconnect = true: automatically revalidate when the browser regains a network connection (via navigator.onLine) (details)

• refreshInterval （详情）：

  ¥refreshInterval (details):

  • 默认禁用：refreshInterval = 0

    ¥Disabled by default: refreshInterval = 0

  • 如果设置为数字，则轮询间隔以毫秒为单位

    ¥If set to a number, polling interval in milliseconds

  • 如果设置为函数，该函数将接收最新数据并应返回以毫秒为单位的间隔

    ¥If set to a function, the function will receive the latest data and should return the interval in milliseconds

• refreshWhenHidden = false：当窗口不可见时进行轮询（如果启用了 refreshInterval）

  ¥refreshWhenHidden = false: polling when the window is invisible (if refreshInterval is enabled)

• refreshWhenOffline = false：浏览器离线时轮询（由 navigator.onLine 决定）

  ¥refreshWhenOffline = false: polling when the browser is offline (determined by navigator.onLine)

• shouldRetryOnError = true：当 fetcher 出错时重试

  ¥shouldRetryOnError = true: retry when fetcher has an error

• dedupingInterval = 2000：在此时间范围内具有相同键的数据去重请求（以毫秒为单位）

  ¥dedupingInterval = 2000: dedupe requests with the same key in this time span in milliseconds

• focusThrottleInterval = 5000：在以毫秒为单位的时间范围内仅重新验证一次

  ¥focusThrottleInterval = 5000: only revalidate once during a time span in milliseconds

• loadingTimeout = 3000：触发 onLoadingSlow 事件的超时时间（以毫秒为单位）

  ¥loadingTimeout = 3000: timeout to trigger the onLoadingSlow event in milliseconds

• errorRetryInterval = 5000：错误重试间隔（以毫秒为单位）

  ¥errorRetryInterval = 5000: error retry interval in milliseconds

• errorRetryCount：最大错误重试次数

  ¥errorRetryCount: max error retry count

• fallback：多个后备数据 （例子） 的键值对象

  ¥fallback: a key-value object of multiple fallback data (example)

• fallbackData：要返回的初始数据（注意：这是每个钩子）

  ¥fallbackData: initial data to be returned (note: This is per-hook)

• keepPreviousData = false：返回前一个键的数据，直到新数据加载完毕 （详情）

  ¥keepPreviousData = false: return the previous key's data until the new data has been loaded (details)

• onLoadingSlow(key, config)：当请求加载时间过长时的回调函数（参见 loadingTimeout）

  ¥onLoadingSlow(key, config): callback function when a request takes too long to load (see loadingTimeout)

• onSuccess(data, key, config)：请求成功完成时的回调函数

  ¥onSuccess(data, key, config): callback function when a request finishes successfully

• onError(err, key, config)：请求返回错误时的回调函数

  ¥onError(err, key, config): callback function when a request returns an error

• onErrorRetry(err, key, config, revalidate, revalidateOps)：错误重试处理程序

  ¥onErrorRetry(err, key, config, revalidate, revalidateOps): handler for error retry

• onDiscarded(key)：由于竞争条件而忽略请求时的回调函数

  ¥onDiscarded(key): callback function when a request is ignored due to race conditions

• compare(a, b)：比较函数用于检测返回的数据何时发生更改，以避免虚假重新渲染。默认情况下，使用 stable-hash (opens in a new tab)。

  ¥compare(a, b): comparison function used to detect when returned data has changed, to avoid spurious rerenders. By default, stable-hash (opens in a new tab) is used.

• isPaused()：函数检测是否暂停重新验证，返回 true 时将忽略获取的数据和错误。默认返回 false。

  ¥isPaused(): function to detect whether pause revalidations, will ignore fetched data and errors when it returns true. Returns false by default.

• use：中间件函数数组 （详情）

  ¥use: array of middleware functions (details)

你还可以使用 全局配置 提供默认选项。

¥You can also use global configuration to provide default options.