version-5-upgrade.md

Upgrading to AngularFire 5.0

AngularFire 5.0 is a refactor of the AngularFireDatabase module. It removes the FirebaseListObservable and FirebaseObjectObservable in favor of a generic based service API.

Updating FirebaseListObservable to AngularFireList<T>

Rather than .list() returning a FirebaseListObservable, it now returns an AngularFireList<T>. This service contains methods that allow you manipulate and stream data.

In the case of streaming back data, you now call one of the observable methods on AngularFireList.

4.0

constructor(afDb: AngularFireDatabase) {
  afDb.list('items').subscribe(console.log);
}

5.0

constructor(afDb: AngularFireDatabase) {
  afDb.list<Item>('items').valueChanges().subscribe(console.log);
}

The same concepts apply to FirebaseObjectObservable to AngularFireObject.

Moving away from $key and $value

In AngularFireDatabase 4.0 the snapshot was automatically unwrapped for you and metadata was placed in $ property. The Firebase Database rejects any keys with $ in them so this mechanism allowed us to provide you with important metadata alongside your actual data. However, persisting the object could be a pain in some cases as the SDK would reject any $ based properties. In 5.0 we have moved away from $ properties and we provide multiple observable methods for receiving the data.

Calling .valueChanges() returns an Observable without any metadata. If you are already persisting the key as a property then you are fine. However, if you are relying on $key, then you need to use .snapshotChanges() and transform the data with an observable .map().

4.0

constructor(afDb: AngularFireDatabase) {
  afDb.list('items').subscribe(items => { 
    const allKeys = items.map(item => item.$key);
  });
}

5.0

constructor(afDb: AngularFireDatabase) {
  afDb.list('items').snapshotChanges().map(actions => {
    return actions.map(action => ({ key: action.key, ...action.payload.val() }));
  }).subscribe(items => {
    return items.map(item => item.key);
  });
}

Data manipulation methods

AngularFire 5.0 removes all custom observables which means their custom operators are gone as well. Instead of using custom operators on either a FirebaseListObservable or a FirebaseObjectObservable, use the methods on the service based APIs: AngularFireList and AngularFireObject. There is no resulting code change, but it worth pointing out.

4.0

constructor(afDb: AngularFireDatabase) {
  const listObservable = afDb.list('items');
  listObservable.push({ name: 'item' });
  listObservable.subscribe();
}

5.0

constructor(afDb: AngularFireDatabase) {
  const afList = afDb.list('items');
  afList.push({ name: 'item' });
  const listObservable = afList.snapshotChanges();
  listObservable.subscribe();
}