Storage

Contents

Storage is an easy way to store key/value pairs and JSON objects. Storage uses a variety of storage engines underneath, picking the best one available depending on the platform.

When running in a native app context, Storage will prioritize using SQLite, as it's one of the most stable and widely used file-based databases, and avoids some of the pitfalls of things like localstorage and IndexedDB, such as the OS deciding to clear out such data in low disk-space situations.

When running in the web or as a Progressive Web App, Storage will attempt to use IndexedDB, WebSQL, and localstorage, in that order.

Usage

First, if you'd like to use SQLite, install the cordova-sqlite-storage plugin:

ionic cordova plugin add cordova-sqlite-storage

Next, install the package (comes by default for Ionic apps > Ionic V1):

npm install --save @ionic/storage

Next, add it to the imports list in your NgModule declaration (for example, in src/app/app.module.ts):

import { IonicStorageModule } from '@ionic/storage'; @NgModule({ declarations: [ // ... ], imports: [ BrowserModule, IonicModule.forRoot(MyApp), IonicStorageModule.forRoot() ], bootstrap: [IonicApp], entryComponents: [ // ... ], providers: [ // ... ] }) export class AppModule {}

Finally, inject it into any of your components or pages:

import { Storage } from '@ionic/storage'; export class MyApp { constructor(private storage: Storage) { } ... // set a key/value storage.set('name', 'Max'); // Or to get a key/value pair storage.get('age').then((val) => { console.log('Your age is', val); }); }

Configuring Storage

The Storage engine can be configured both with specific storage engine priorities, or custom configuration options to pass to localForage. See the localForage config docs for possible options: https://github.com/localForage/localForage#configuration

Note: Any custom configurations will be merged with the default configuration

import { IonicStorageModule } from '@ionic/storage'; @NgModule({ declarations: [...], imports: [ IonicStorageModule.forRoot({ name: '__mydb', driverOrder: ['indexeddb', 'sqlite', 'websql'] }) ], bootstrap: [...], entryComponents: [...], providers: [...] }) export class AppModule { }

Instance Members

constructor

Create a new Storage instance using the order of drivers and any additional config options to pass to LocalForage.

Possible driver options are: ['sqlite', 'indexeddb', 'websql', 'localstorage'] and the default is that exact ordering.



driver

Get the name of the driver being used.



clear()

Clear the entire key value store. WARNING: HOT!

Returns: Returns a promise that resolves when the store is cleared



forEach()

Iterate through each key,value pair.

Returns: Returns a promise that resolves when the iteration has finished.

Parameters

iteratorCallback
a callback of the form (value, key, iterationNumber)


get()

Get the value associated with the given key.

Returns: Returns a promise with the value of the given key

Parameters

key
Type: string
the key to identify this value


keys()

Returns: Returns a promise that resolves with the keys in the store.



length()

Returns: Returns a promise that resolves with the number of keys stored.



ready()

Reflect the readiness of the store.

Returns: Returns a promise that resolves when the store is ready



remove()

Remove any value associated with this key.

Returns: Returns a promise that resolves when the value is removed

Parameters

key
Type: string
the key to identify this value


set()

Set the value for the given key.

Returns: Returns a promise that resolves when the key and value are set

Parameters

key
Type: string
the key to identify this value
value
Type: any
the value for this key


Edit this page Updated 2019-01-23
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