Firebase.push failed: first argument contains an invalid key ($$hashKey)

Question

I recently started learning AngularJS+Firebase. I\'m trying to write in my firebase an object like this:

{
    title: \"Personal Information\",
    say: [
               


        

Answer 1

I'm a bit late to this but I thought I would like to add my two cents as I was shaking my head to all the other answers. Hopefully this can help you to avoid this issue all together.

Use the angularFire library intended to handle angular data and use it's methods.

while yes you can use the pure javascript library methods to .push() .add() .update(), .set() ect.

So if you want to avoid any clashes when firebase communicates with angular javascript you need to be using the appropriate .$foo() methods (i.e. .$save()). In your case just add the $ to your .add() (make it .$add())

so use lessondata.$add($scope.topic);

differences when saving with firebase's vs angularfire's

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AngularFire's $save() method is implemented using Firebase's set() method.

Firebase's push() operation corresponds to AngularFire's $add() method

Typically you should be using set()/$save() if you either have an object that already exists in the database or if you are working with objects that have a natural key. more info on that here: https://stackoverflow.com/a/35959496/4642530

Things to note with AngularFire

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For a callback:

and if you want a callback to know if your data saved correctly you can do something like this:

var list = $firebaseArray(ref);
list.$add({ foo: "bar" }).then(function(ref) {
  var id = ref.key();
  console.log("added record with id " + id);
  list.$indexFor(id); // returns location in the array
});

I was surprised this wasn't mentioned earlier in any of the other answers, but take a look at these docs https://www.firebase.com/docs/web/libraries/angular/api.html#angularfire-firebasearray-addnewdata

Cheers.