Module AsyncStorage-BsReactNative

AsyncStorage is a simple, unencrypted, asynchronous, persistent, key-value storage system that is global to the app. It should be used instead of LocalStorage.

It is recommended that you use an abstraction on top of AsyncStorage instead of AsyncStorage directly for anything more than light usage since it operates globally.

On iOS, AsyncStorage is backed by native code that stores small values in a serialized dictionary and larger values in separate files. On Android, AsyncStorage will use either RocksDB or SQLite based on what is available.

The AsyncStorage JavaScript code is a simple facade that provides a clear JavaScript API, real Error objects, and simple non-multi functions. Each method in the API returns a JS.Promise.

You can read more on AsyncStorage API usage in official docs: https://facebook.github.io/react-native/docs/asyncstorage

Methods

getItem

let getItem:
(string, ~callback: (option(error), option(string)) => unit=?, unit) =>
Js.Promise.t(option(string));

Fetches an item for a key provided as first argument and invokes a callback upon completion.

setItem

let setItem:
(string, string, ~callback: option(error) => unit=?, unit) =>
Js.Promise.t(unit);

Sets the value for a key provided as first argument and invokes a callback upon completion.

removeItem

  let removeItem:
(string, ~callback: option(error) => unit=?, unit) => Js.Promise.t(unit);

Removes an item for a key provided as first argument and invokes a callback upon completion.

mergeItem

  let mergeItem:
(string, string, ~callback: option(error) => unit=?, unit) =>
Js.Promise.t(unit);

Merges an existing key provided as first argument with an input value, assuming both values are stringified JSON.

clear

let clear: (~callback: option(error) => unit=?, unit) => Js.Promise.t(unit);

Erases all AsyncStorage for all clients, libraries, etc. You probably don't want to call this; use removeItem or multiRemove to clear only your app's keys.

getAllKeys

  let getAllKeys:
(~callback: (option(error), option(array(string))) => unit=?, unit) =>
Js.Promise.t(option(array(string)));

Gets all keys known to your app; for all callers, libraries, etc.

flushGetRequests

    [@bs.scope "AsyncStorage"] [@bs.module "react-native"]
external flushGetRequests: unit => unit = "";

Flushes any pending requests using a single batch call to get the data.

multiGet

  let multiGet:
(
  array(string),
  ~callback: (option(array(error)), option(array(array(string)))) =>
             unit
               =?,
  unit
) =>
Js.Promise.t(option(array(array(string))));

This allows you to batch the fetching of items given an array of key inputs. Your callback will be invoked with an array of corresponding key-value pairs found

multiSet

  let multiSet:
(
  array((string, string)),
  ~callback: option(array(error)) => unit=?,
  unit
) =>
Js.Promise.t(unit);

Use this as a batch operation for storing multiple key-value pairs. When the operation completes you'll get a single callback with any errors:

multiRemove

  let multiRemove:
(array(string), ~callback: option(array(error)) => unit=?, unit) =>
Js.Promise.t(unit);

Call this to batch the deletion of all keys in the keys array

multiMerge

  let multiMerge:
(
  array((string, string)),
  ~callback: option(array(error)) => unit=?,
  unit
) =>
Js.Promise.t(unit);

Batch operation to merge in existing and new values for a given set of keys. This assumes that the values are stringified JSON

NOT SUPPORTED for all native implementations