AngularFire2 Offline

🔌 A simple wrapper for AngularFire2 to read and write to Firebase while offline, even after a complete refresh.

• Complete changelog

Demos

• Angular 2+ Demos: Read object, Read list, Write object, Write list -- tutorial 📗
• Ionic 2+ Demo -- tutorial 📘

Legacy Versions

• Upgrading from 2.x to 4.x for AngularFire2? Try the upgrade tutorial
• To support AngularFire2 2.x use the @two branch of this repo for install instructions and tutorials (Angular/Ionic).
• This branch (master) is a wrapper for the latest version of AngularFire2 (4.x)

Install

npm install angularfire2-offline angularfire2 firebase --save

Setup @NgModule

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AngularFireModule } from 'angularfire2';
import { AngularFireOfflineModule } from 'angularfire2-offline';
import { AngularFireDatabaseModule } from 'angularfire2/database';

import { AppComponent } from './app.component';

export const firebaseConfig = {
  apiKey: '<your-key>',
  authDomain: '<your-project-authdomain>',
  databaseURL: '<your-database-URL>',
  storageBucket: '<your-storage-bucket>'
};

@NgModule({
  declarations: [AppComponent],
  imports: [
    AngularFireDatabaseModule,
    AngularFireModule.initializeApp(firebaseConfig),
    AngularFireOfflineModule,
    BrowserModule
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

Usage

• Methods mirror AngularFire2 database methods for object and list.

Read Data Offline

• Querying lists is supported
• preserveSnapshot is not supported

import { Component } from '@angular/core';
import {
  AfoListObservable,
  AfoObjectObservable,
  AngularFireOfflineDatabase } from 'angularfire2-offline/database';

@Component({
  selector: 'project-name-app',
  template: `
  <h1>{{ (info | async)?.name }}</h1>
  <ul>
    <li *ngFor="let item of items | async">
      {{ item?.name }}
    </li>
  </ul>
  `
})
export class MyApp {
  info: AfoObjectObservable<any>;
  items: AfoListObservable<any[]>;
  constructor(afoDatabase: AngularFireOfflineDatabase) {
    this.info = afoDatabase.object('/info');
    this.items = afoDatabase.list('/items');
  }
}

Write data offline

If writes are made offline followed by a page refresh, the writes will be sent when a connection becomes available.

• Write object
• Write list
• Resolve write conflicts

AngularFire2 Offline specific features

In addition to wrapping most database features from AngularFire2, a minimal amount of offline specific features are provided:

Offline promises

• Regular promises - Making a write to Firebase will return a promise as expected. The promise will complete after the data has been saved to Firebase.
• Offline promises - If you application only needs to know when the write has been saved offline (which will sync on reconnect) you can access the offline promise within the regular promise by calling promise.offline.then().

Offline promise example

const promise = this.afoDatabase.object('car').update({maxSpeed: 100});
promise.offline.then(() => console.log('offline data saved to device storage!'));
promise.then(() => console.log('data saved to Firebase!'));

Also see working with promises

reset - delete offline data

The reset method is useful for deleting sensitive data when a user signs out of an application. This also helps prevent permission errors when using Firebase auth.

Use reset with caution

If writes are made while offline reset will delete them before they can reach Firebase.

reset example

onUserSignout() {
  this.afoDatabase.reset()
}

Calling reset on specific references

You can reset a specific Firebase reference by passing the reference string to the reset method

onUserSignout() {
  this.afoDatabase.reset('my/firebase/ref')
}

How it works

• While online, Firebase data is stored locally (as data changes the local store is updated)
• While offline, local data is served if available, and writes are stored locally
• On reconnect, app updates with new Firebase data, and writes are sent to Firebase
• Even while online, local data is used first when available which results in a faster load

Contributing to AngularFire2 Offline

Pull requests are welcome! If you have a suggested enhancement, please open an issue. Thanks!

Here is how you can setup a development environment:

Clone repo

1. git clone https://github.com/adriancarriger/angularfire2-offline.git
2. cd angularfire2-offline

Setup example

1. cd examples/angular-cli
2. yarn
3. npm start

Setup development environment

1. Open a new shell/terminal
2. cd angularfire2-offline
3. yarn
4. npm run start-dev

License

angularfire2-offline is licensed under the MIT Open Source license. For more information, see the LICENSE file in this repository.