How to push data into subcollections in firebase

Question

I'm creating a messaging app with react-native & firebase. Its working quite alright.

Now i want to take it a step further by creating private chats. To my understanding, i need to populate the data into subcollections. e.g : chats>chatroom1>data, chats>chatroom2>data e.t.c

I'm currently working with this code

import firebase from 'firebase';

class Fire {
  constructor (props) {
    this.init()
    this.checkAuth()
  }

  init = () => {
    if (!firebase.apps.length) {

    }
  };

  checkAuth = () => {
    firebase.auth().onAuthStateChanged(user => {
      if (!user) {
        firebase.auth().signInAnonymously();
      }
    })
  } 

  send = messages  => {
    messages.forEach(item => {
      const message = {
        text: item.text,
        timestamp: firebase.database.ServerValue.TIMESTAMP,
        user: item.name 
      }

      this.db.push(message)
    })
  }  

  parse = message => {
    const {user, text, timestamp} = message.val();
    const {key, _id} = message
    const createdAt = new Date(timestamp)

    return {
      _id,
      createdAt,
      text,
      user
    }
  }

  get = callback => {
    this.db.on('child_added', snapshot => callback(this.parse(snapshot)))
  }

  off() {
    this.db.off()
  }

  get db() {
    return firebase.database().ref("messages");
  }

  get uid(){
    return(firebase.auth().currentUser || {}).uid
  }
}

How can I populate the subcollections from this code?

I believe for calling out of specific subcollections, firebase.database().ref("messages/chatroomid"); will do the trick, right?

what i mean by sub collection is this

Currently my JSON tree looks like:

database
    - messages
         - mvhhsjsfurhcb
               - text: "hi"
                 timestamp: 9942313949
                 user: "David"

firebase.database().ref("messages"); calls out the data under messages

This is what i want

 database
        - messages
               -chatroom1
                   - mvhhsjsfurhcb
                         - text: "hi"
                           timestamp: 9942313949
                           user: "David"
               -chatroom2
                   - mvhhsjsfurhcb
                         - text: "hey, this i room2"
                           timestamp: 9942313949
                           user: "Sam"

Then for firebase.database().ref("messages/chatroom1"); to call out only messages in chatroom1.

What I intend to achieve with this is to create a private chat for users

To give you more insight, if I was to do this with PHP, I would be doing SELECT * WHERE chatroom = :chatroom;

i believe the answer will be related to this.db.push(message). maybe adding another '.' indicating that there's another branch before pushing the message

The Firebase Realtime Database doesn't have the concept of collections. Instead the data is stored in one big tree of nodes, also known as a JSON tree. Can you clarify what you mean by "subcollection" in the context of this? — Frank van Puffelen, Apr 29 '21 at 22:23
But if you want to move from having a single list of messages, to having multiple rooms with messages, you'll indeed add a layer with the room ID in the JSON hierarchy as you're showing. If you're looking for ideas on how to determine keys for the rooms. have a look at https://stackoverflow.com/questions/33540479/best-way-to-manage-chat-channels-in-firebase — Frank van Puffelen, Apr 29 '21 at 22:25
@FrankvanPuffelen Thank you, i edited the question as requested in your first comment — kunlee, Apr 29 '21 at 23:33
That structure looks good for a multi-chatroom app. For private chat between users, and how to ensure each user can find their chatrooms, see the link I gave earlier as it addresses both. — Frank van Puffelen, Apr 30 '21 at 00:37
i understand the idea of storing userid...my question now is this, `this.db.push(message)` pushes into `datbase>messages>data`.How do i get it to push into `database>messages>chatroomid>data`. I don't think the link addresses that. I'm used to php for my backend, i apologize if its something i should know. @FrankvanPuffelen — kunlee, Apr 30 '21 at 07:14

score 1 · Accepted Answer · answered Apr 30 '21 at 13:23

1

If you want to push the chat message to a specific chat room, you can do:

  this.db.child("chatroomid1").push(message)

answered Apr 30 '21 at 13:23

Frank van Puffelen

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How to push data into subcollections in firebase

1 Answers1