Ionic Storage Module: Ionic 2

This video tutorial is an update to our previous tutorial Ionic Storage: Ionic 2.

Major Changes To Note
Previously we use to import Storage class inside src/app/app.module.ts file and we would list it as one of the providers. But now we need to import IonicStorageModule class inside src/app/app.module.ts file and list it inside imports array. That’s the only difference in implementing Ionic Storage, everything else is as described in Ionic Storage: Ionic 2 video tutorial.

In this video tutorial only concentrate on src/app/app.module.ts file and for implementing storage set and get method refer Ionic Storage: Ionic 2 video tutorial itself.

Ionic Storage Module In Ionic 2 (Update)

src/app/app.module.ts

import { NgModule, ErrorHandler } from '@angular/core';
import { IonicApp, IonicModule, IonicErrorHandler } from 'ionic-angular';
import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
 
import { IonicStorageModule } from '@ionic/storage';
 
@NgModule({
  declarations: [
    MyApp,
    HomePage
  ],
  imports: [
    IonicModule.forRoot(MyApp),
    IonicStorageModule.forRoot()
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage
  ],
  providers: [
    {provide: ErrorHandler, useClass: IonicErrorHandler}
  ]
})
export class AppModule {}

Here we import IonicStorageModule class and list it inside imports array. We can also specify database name and database preference as follows:

imports: [
    IonicModule.forRoot(MyApp),
    IonicStorageModule.forRoot({
      name: '__mydbName',
      driverOrder: ['sqlite', 'indexeddb', 'websql']
    })
  ]

Now implementing get and set methods wherever we need it. Practically it would be useful inside a data provider file, but in this tutorial am implementing inside a normal page, so that I keep the complexities out for this basic lesson.

src/pages/home/home.ts

import { Component } from '@angular/core';
 
import { NavController } from 'ionic-angular';
 
import { Storage } from '@ionic/storage';
 
@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
 
  constructor(public storage: Storage, public navCtrl: NavController) {
    this.storage.ready().then(() => {
     this.storage.set('myKey', 10);
    });
  };
 
  getValues(){
     this.storage.get('myKey').then((data) => {
       if(data != null)
       {
         console.log(data);
       }
     });
  };

Here we import Storage class and create an instance of it. We check if the storage is ready. Once its ready it returns/resolves a promise. So now we can set value using this.storage.set() method. We can set an object, an array or a strong value or simply a number.

We can get the value by using its get method, which returns the value stored in the key as promise. If nothing is stored in the key, it returns null.