Multi tool use

Firebase Web - Is it possible to get the value's name?

is there a way for me to retrieve the name of a value?
For example:

I want to get the value names highlighted in yellow.

However, right now I can only get:

From my understanding the below code only return the value which is the player's scores.

var childData = childSnapshot.val();


Can I do something like this to get the value name?

var childValueName = childSnapshot.val().name;


This is my java code:

function PrintData()
{
var ref = firebase.database().ref('Score');
var PrintData = document.getElementById('PrintOutData');

ref.on("value", function(snapshot)
{
PrintData.innerText = "";
snapshot.forEach(function(childSnapshot)
{
console.log("childSnapshot.key: " + childSnapshot.key);
var childData = childSnapshot.val();
let keys = Object.keys(childData)
keys.forEach(key => {
let value = childData[key.toString()];
console.log("value: " + value);
PrintData.innerText += childSnapshot.key + ": " + value +"r";
})
});
});
}


My html code:

<button type="button" onclick="PrintData()">Print!</button>


Please correct me if I am wrong! Thankyou.

value name

tag name

childSnapshot

key

keys.forEach

4 Answers
4

Firebase has a well versed and beautiful documentation.
According to firebase documentation, datasnapshot is returned when you pass a relative path to the child() method

// Assume we have the following data in the Database:
{
"name": {
"first": "Ada",
"last": "Lovelace"
}
}

// Test for the existence of certain keys within a DataSnapshot
var ref = firebase.database().ref("users/ada");
ref.once("value")
.then(function(snapshot) {
var name = snapshot.child("name").val(); // {first:"Ada",last:"Lovelace"}
var firstName = snapshot.child("name/first").val(); // "Ada"
var lastName = snapshot.child("name").child("last").val(); // "Lovelace"
var age = snapshot.child("age").val(); // null
});


The following may work for your purpose:

firebase.database().ref('score').once('value', snap => {
var data = snap.val() // should return => {User1: {GamePlay00: 3}, User2:
{GamePlay00: 1}, ...}

var users = Object.keys('data') should return // => [User1, User2, ...]

var usersDatas = users.map(user_id => data[user_id]) // should return something like => [{gamePlay00: 3}, {gamePlay00:1}, ...]

var value = usersDatas.map(game_play_id => game_play_id) // should return => [gamePlay00, gamePlay00...]
})


Please refer to these link for further documentation: Object.keys Firebase Docs

I'd stick to using Snapshot.forEach() for the lower level too:

Snapshot.forEach()

var ref = firebase.database().ref('Score');
var PrintData = document.getElementById('PrintOutData');

ref.on("value", function(snapshot) {
PrintData.innerText = "";
snapshot.forEach(function(userSnapshot) {
console.log("childSnapshot.key: " + userSnapshot.key);
userSnapshot.forEach(function(gameSnapshot) {
PrintData.innerText += gameSnapshot.key + ": " + gameSnapshot.val() +"r";
})
});
});


See firebase.database.DataSnapshot

key
(string or null)

The key (last part of the path) of the location of this DataSnapshot.

The last token in a Database location is considered its key. For example, "ada" is the key for the /users/ada/ node. Accessing the key on any DataSnapshot will return the key for the location that generated it. However, accessing the key on the root URL of a Database will return null.

DataSnapshot

null

// Assume we have the following data in the Database:
{
"name": {
"first": "Ada",
"last": "Lovelace"
}
}

var ref = firebase.database().ref("users/ada");
ref.once("value")
.then(function(snapshot) {
var key = snapshot.key; // "ada"
var childKey = snapshot.child("name/last").key; // "last"
});


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