Interface PublicConfiguration<Data, Error, Fn>

Link

https://swr.vercel.app/docs/options

interface PublicConfiguration<
    Data = any,
    Error = any,
    Fn extends Fetcher = BareFetcher,
> {
    errorRetryInterval: number;
    errorRetryCount?: number;
    loadingTimeout: number;
    focusThrottleInterval: number;
    dedupingInterval: number;
    refreshInterval?: number | (latestData: undefined | Data) => number;
    refreshWhenHidden?: boolean;
    refreshWhenOffline?: boolean;
    revalidateOnFocus: boolean;
    revalidateOnReconnect: boolean;
    revalidateOnMount?: boolean;
    revalidateIfStale: boolean;
    shouldRetryOnError: boolean | (err: Error) => boolean;
    keepPreviousData?: boolean;
    suspense?: boolean;
    fallbackData?: Data | Promise<Data>;
    fetcher?: Fn;
    use?: Middleware[];
    fallback: { [key: string]: any };
    isPaused: () => boolean;
    onLoadingSlow: (
        key: string,
        config: Readonly<PublicConfiguration<Data, Error, Fn>>,
    ) => void;
    onSuccess: (
        data: Data,
        key: string,
        config: Readonly<PublicConfiguration<Data, Error, Fn>>,
    ) => void;
    onError: (
        err: Error,
        key: string,
        config: Readonly<PublicConfiguration<Data, Error, Fn>>,
    ) => void;
    onErrorRetry: (
        err: Error,
        key: string,
        config: Readonly<PublicConfiguration<Data, Error, Fn>>,
        revalidate: Revalidator,
        revalidateOpts: Required<RevalidatorOptions>,
    ) => void;
    onDiscarded: (key: string) => void;
    compare: (a: undefined | Data, b: undefined | Data) => boolean;
    isOnline: () => boolean;
    isVisible: () => boolean;
}

Type Parameters

Properties

errorRetryInterval errorRetryCount? loadingTimeout focusThrottleInterval dedupingInterval refreshInterval? refreshWhenHidden? refreshWhenOffline? revalidateOnFocus revalidateOnReconnect revalidateOnMount? revalidateIfStale shouldRetryOnError keepPreviousData? suspense? fallbackData? fetcher? use? fallback isPaused onLoadingSlow onSuccess onError onErrorRetry onDiscarded compare isOnline isVisible

Properties

errorRetryInterval

errorRetryInterval: number

error retry interval in milliseconds

Default Value

5000

OptionalerrorRetryCount

errorRetryCount?: number

max error retry count

loadingTimeout

loadingTimeout: number

timeout to trigger the onLoadingSlow event in milliseconds

Default Value

3000

focusThrottleInterval

focusThrottleInterval: number

only revalidate once during a time span in milliseconds

Default Value

5000

dedupingInterval

dedupingInterval: number

dedupe requests with the same key in this time span in milliseconds

Default Value

2000

OptionalrefreshInterval

refreshInterval?: number | (latestData: undefined | Data) => number

Link

https://swr.vercel.app/docs/revalidation

  • 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

OptionalrefreshWhenHidden

refreshWhenHidden?: boolean

polling when the window is invisible (if refreshInterval is enabled)

Default Value

false

OptionalrefreshWhenOffline

refreshWhenOffline?: boolean

polling when the browser is offline (determined by navigator.onLine)

revalidateOnFocus

revalidateOnFocus: boolean

automatically revalidate when window gets focused

Default Value

true

Link

https://swr.vercel.app/docs/revalidation

revalidateOnReconnect

revalidateOnReconnect: boolean

automatically revalidate when the browser regains a network connection (via navigator.onLine)

Default Value

true

Link

https://swr.vercel.app/docs/revalidation

OptionalrevalidateOnMount

revalidateOnMount?: boolean

enable or disable automatic revalidation when component is mounted

revalidateIfStale

revalidateIfStale: boolean

automatically revalidate even if there is stale data

Default Value

true

Link

https://swr.vercel.app/docs/revalidation#disable-automatic-revalidations

shouldRetryOnError

shouldRetryOnError: boolean | (err: Error) => boolean

retry when fetcher has an error

Default Value

true

OptionalkeepPreviousData

keepPreviousData?: boolean

keep the previous result when key is changed but data is not ready

Default Value

false

Optional Experimentalsuspense

suspense?: boolean

enable React Suspense mode

Default Value

false

Link

https://swr.vercel.app/docs/suspense

OptionalfallbackData

fallbackData?: Data | Promise<Data>

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

Link

https://swr.vercel.app/docs/with-nextjs

Optionalfetcher

fetcher?: Fn

the fetcher function

Optionaluse

use?: Middleware[]

array of middleware functions

Link

https://swr.vercel.app/docs/middleware

fallback

fallback: { [key: string]: any }

a key-value object of multiple fallback data

Link

https://swr.vercel.app/docs/with-nextjs#pre-rendering-with-default-data

isPaused

isPaused: () => boolean

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

onLoadingSlow

onLoadingSlow: (
    key: string,
    config: Readonly<PublicConfiguration<Data, Error, Fn>>,
) => void

callback function when a request takes too long to load (see loadingTimeout)

onSuccess

onSuccess: (
    data: Data,
    key: string,
    config: Readonly<PublicConfiguration<Data, Error, Fn>>,
) => void

callback function when a request finishes successfully

onError

onError: (
    err: Error,
    key: string,
    config: Readonly<PublicConfiguration<Data, Error, Fn>>,
) => void

callback function when a request returns an error

onErrorRetry

onErrorRetry: (
    err: Error,
    key: string,
    config: Readonly<PublicConfiguration<Data, Error, Fn>>,
    revalidate: Revalidator,
    revalidateOpts: Required<RevalidatorOptions>,
) => void

handler for error retry

onDiscarded

onDiscarded: (key: string) => void

callback function when a request is ignored

compare

compare: (a: undefined | Data, b: undefined | Data) => boolean

comparison function used to detect when returned data has changed, to avoid spurious rerenders. By default, stable-hash is used.

isOnline

isOnline: () => boolean

isOnline and isVisible are functions that return a boolean, to determine if the application is "active". By default, SWR will bail out a revalidation if these conditions are not met.

Link

https://swr.vercel.app/docs/advanced/react-native#customize-focus-and-reconnect-events

isVisible

isVisible: () => boolean

isOnline and isVisible are functions that return a boolean, to determine if the application is "active". By default, SWR will bail out a revalidation if these conditions are not met.

Link

https://swr.vercel.app/docs/advanced/react-native#customize-focus-and-reconnect-events

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