CODEWITHSUNDEEP
androidlistfirebasefirebase-realtime-database
Nick Titov
Nick Titov

Reputation: 598

Firebase add item to array dynamically

I am trying to make some kind of comments using Firebase for Android. Just have one question, are there any way to add new items to array?

For example, if I have such kind of object enter image description here

If I am trying to push, it will convert it to map enter image description here

And I don't want to overwrite this object each time, because I will have multiuser support and it will fail at some point.

And I am trying to do it as a List to do not create DataTransferObjects for my models, and to support auto parsing using firebase.

Thanks! If there will be no ideas will go with creating Maps, actually.

My ObjectModel:

public class Company implements Parcelable {
    private String id;
    private String name;
    private String description;
    private List<Comment> comments;
}

Code for pushing item:

final DatabaseReference ref = companiesRef.child(companyId).child(NODE_COMMENTS).push();
        return Single.create(e -> ref.setValue(comment)
                .addOnCompleteListener(task -> {
                    e.onSuccess(task.isSuccessful());
                }));

Upvotes: 0

Views: 1254

Answers (2)

Brayan Armando Yaquian Gonzale
Brayan Armando Yaquian Gonzale

Reputation: 620

You do not need to have a Model Class to write in Firebase, you can parse a JSON to Java Objects dinamically with Jackson and push it into Firebase.

You can parse a JSON as Java Objects with Jackson

. For example you can obtain: Object, List, Hashmap, Integer, String, etc. without POJO classes.

To see more please visit this answer

Upvotes: 0

UmarZaii
UmarZaii

Reputation: 1351

This is how it works, look at the example below I have stored "0" as my first commentID and "1" as my second commentID. As you can see, I stored the lastCommentID as the commentID for the last comment in the lists.

{
  "comments": {
    "0": {
      "text": "mycomment",
      "time": "142351516"
    },
    "1": {
      "text": "secondcomment",
      "time": "153426564"
    }
  }

 "lastCommentId": "1"
}

So whenever you want to add new comment to the firebase you have to retrieve the lastCommentID first as a string and convert it to integer(E.g. 1) then add 1 to the value(E.g. 2) so that when you save the next comment it won't override the previous version.

Note that you have replace lastCommentID each time you add comment to the database.

{
  "comments": {
    "0": {
      "text": "mycomment",
      "time": "142351516"
    },
    "1": {
      "text": "secondcomment",
      "time": "153426564"
    },
    "2": {
      "text": "thirdcomment",
      "time": "153426564"
    }
  }

 "lastCommentId": "2"
}

Upvotes: 1

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