AsyncStorage
AsyncStorage is an 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.
This JS code is a facade over the native iOS implementation to provide a clear JS API, real Error objects, and non-multi functions. Each method returns a Promise
object.
Methods
Reference
Methods
getItem()
static getItem(key, callback?)
Fetches key
and passes the result to callback
, along with an Error
if there is any. Returns a Promise
object.
setItem()
static setItem(key, value, callback?)
Sets value
for key
and calls callback
on completion, along with an Error
if there is any. Returns a Promise
object.
removeItem()
static removeItem(key, callback?)
Returns a Promise
object.
mergeItem()
static mergeItem(key, value, callback?)
Merges existing value with input value, assuming they are stringified json. Returns a Promise
object. Not supported by all native implementations.
clear()
static clear(callback?)
Erases all AsyncStorage for all clients, libraries, etc. You probably don't want to call this - use removeItem or multiRemove to clear only your own keys instead. Returns a Promise
object.
getAllKeys()
static getAllKeys(callback?)
Gets all keys known to the app, for all callers, libraries, etc. Returns a Promise
object.
multiGet()
static multiGet(keys, callback?)
multiGet invokes callback with an array of key-value pair arrays that matches the input format of multiSet. Returns a Promise
object.
multiGet(['k1', 'k2'], cb) -> cb([['k1', 'val1'], ['k2', 'val2']])
multiSet()
static multiSet(keyValuePairs, callback?)
multiSet and multiMerge take arrays of key-value array pairs that match the output of multiGet, e.g. Returns a Promise
object.
multiSet([['k1', 'val1'], ['k2', 'val2']], cb);
multiRemove()
static multiRemove(keys, callback?)
Delete all the keys in the keys
array. Returns a Promise
object.
multiMerge()
static multiMerge(keyValuePairs, callback?)
Merges existing values with input values, assuming they are stringified json. Returns a Promise
object.
Not supported by all native implementations.