API Options ​

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

Parameters ​

• key - A unique key for the request. Can be an string | array | function | falsy value
• fetcher - A Promise that resolves to the data that you want to use
• options - (optional) an object of options for this SWR composable

Return Values ​

• data - data for the given key resolved by fetcher (or undefined if not loaded)
• error - error thrown by fetcher (or undefined if nothing threw)
• isValidating - if there's the first request or revalidation going on
• mutate(updateFn, options?) - function to mutate the cached data. More details

Options ​

• revalidateOnFocus = true - Automatically revalidate when window gets focused
• revalidateOnReconnect = true - Automatically revalidate when the browser regains a network connection
• revalidateIfStale = true - Automatically revalidate if there is stale data
• dedupingInterval = 2000 - dedupe requests with the same key in this time span in milliseconds
• fallback - a key-value object of multiple fallback data
• fallbackData - initial data to be returned (this has priority over fallback option)
• focusThrottleInterval = 5000 - only revalidate on focus once during a time span in milliseconds
• refreshInterval = 0 - (details)
  • Disabled by default: refreshInterval = 0
  • If set to a number, polling interval in milliseconds
  • If set to a function, the function will receive the latest data and should return the interval in milliseconds
• refreshWhenHidden = false - polling when the window is invisible (if refreshInterval is enabled),
• refreshWhenOffline = false - polling when the browser is offline (determined by navigator.onLine),
• onSuccess(data, key, config) - callback function when a request finishes successfully
• onError(err, key, config) - callback function when a request returns an error