CODEWITHSUNDEEP
angularrxjsgoogle-cloud-firestoreangularfire2
FiringBlanks
FiringBlanks

Reputation: 2084

Do something whenever a new document is added to collection

Listening for updates to a collection in angularfire2 is easy enough. I want to also run a function whenever the new item is added to (or removed from) the collection. Here's some sample code:: 

let path = 'doc1/' + doc2 + '/doc3/';

this.varCollection = this.afs.collection(path);
this.var = this.varCollection.valueChanges();          //Do something here?

Upvotes: 1

Views: 82

Answers (1)

Julius Dzidzevičius
Julius Dzidzevičius

Reputation: 11000

valueChanges() returns an Observable so you can subscribe it as so:

this.subscription = this.varCollection.valueChanges().subscribe((val) => {
  this.var = val;  
  runSomeFunc();
})

In case you use an async pipe in your template or just want to keep Observable as it is, try to .map() it and then return:

this.var = this.varCollection.valueChanges().map(_ => {console.log('value changed'); return _});

If you need document's metadata, can use snapshotChanges():

this.subscription = this.varCollection.snapshotChanges().subscribe( //do something )

Upvotes: 1

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