Using JavaScript, what is the process for getting the value of a child node within Firebase

var ref = firebase.database().ref("games/" + gameId + "/patterns");
ref.on("child_changed", function(snapshot){
  var pattern = snapshot.key;
  console.log(pattern);
});

Currently, the code snippet above only logs the key. But how can I extract the player name whose status is equal to 0?

I noticed that the snapshot contains all the child data I need when I use the following code:

var ref = firebase.database().ref("games/" + gameId + "/patterns");
ref.on("child_changed", function(snapshot){
  var value = snapshot.val();

  console.log(value);
});

Even though I am able to access the data using this approach, I'm still struggling to extract the specific child's data as required.

Answer №1

When you extract the value, it comes as a standard JavaScript/JSON object. This allows you to access its members just like any other JavaScript object. Firebase converts your keys at levels 1, 2, and 3 into an array, which results in adding a null item at the beginning of that array. To learn more about this process, check out: Firebase database returns null at beginning of each new node

If you want to iterate over all child nodes under the patterns child that has been modified and retrieve the players with a status of 0, you can use the following code:

var ref = firebase.database().ref("games/" + gameId + "/patterns");
ref.on("child_changed", function(snapshot){
  snapshot.forEach(function(child) {
    if (child.val() && child.val().status == "0") {
      console.log(child.val().player);
    });
  });
});

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