Angular Local-Storage-Service with RxJs Observables

Subscribe to all localstorage events Subscribe to when and what data is stored in localstorage Subscribe to when and what data is modified in localstorage Subscribe to when and what data is removed from localstorage] Subscribe to last and what saved data that was stored in localstorage Subscribe to when and what data is evicted or deleted from localstorage

This project was generated with Angular CLI version 1.2.1.

import { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs/BehaviorSubject';

interface ICache { [ key: string ]: BehaviorSubject<any>; }
type serializable = object | Object;

@Injectable()
export class LocalStorageService {
  private cache: ICache;

  constructor () {
    this.cache = Object.create( null );
  }

  setItem<T extends serializable>( key: string, value: T ): BehaviorSubject<T> {
    localStorage.setItem( key, JSON.stringify( value ) );

    if ( this.cache[ key ] ) {
      this.cache[ key ].next( value );
      return this.cache[ key ];
    }

    return this.cache[ key ] = new BehaviorSubject( value );
  }

  getItem<T extends serializable>( key: string ): BehaviorSubject<T> {
    if ( this.cache[ key ] )
      return this.cache[ key ];
    else
      return this.cache[ key ] = new BehaviorSubject( JSON.parse( localStorage.getItem( key ) ) );
  }

  removeItem ( key: string ) {
    localStorage.removeItem( key );
    if ( this.cache[ key ] )
      this.cache[ key ].next( undefined );
  }
}

Development server

Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any of the source files.

Code scaffolding

Run ng generate component component-name to generate a new component. You can also use ng generate directive|pipe|service|class|module.

Build

Run ng build to build the project. The build artifacts will be stored in the dist/ directory. Use the -prod flag for a production build.

Running unit tests

Run ng test to execute the unit tests via Karma.

Running end-to-end tests

Run ng e2e to execute the end-to-end tests via Protractor. Before running the tests make sure you are serving the app via ng serve.

Further help

To get more help on the Angular CLI use ng help or go check out the Angular CLI README.