Storage

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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:

cordova plugin add cordova-sqlite-storage --save

Next, install the package (comes by default for Ionic 2 apps >= RC.0)

npm install --save @ionic/storage

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

import { IonicStorageModule } from '@ionic/storage';

@NgModule({
  declarations: [
    // ...
  ],
  imports: [
    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(storage: Storage) {

     storage.ready().then(() => {

       // 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

driver

Get the name of the driver being used.

ready()

Reflect the readiness of the store.

get(key)

Get the value associated with the given key.

set(key, value)

Set the value for the given key.

remove(key)

Remove any value associated with this key.

clear()

Clear the entire key value store. WARNING: HOT!

length()

keys()

forEach(iteratorCallback)

Iterate through each key,value pair.