How to get database information from Firebase database once

Question

I've looked everywhere, and no place has given me a satisfactory answer; how do I just simply retrieve data from the Firebase Database when I want it? I don't want to syncronize the data, I just want to get the data when I call for it. Various attempts using once() have failed entirely, not getting me close at all. Is it even possible or is Firebase just not designed for what I'm trying to do?

EDIT: Minimal example of what I want to do:

let ref = firebase.database().ref("location1");
let intendedValue = "Data not Gathered";
ref.once("value").then( function(snapshot) {
  intendedValue = snapshot.val();
});
console.log(intendedValue);

Where my firebase database has the structure:

projectFolder:
    location1:
        datapoint1: "dataValue1";

So you'd think this would log "dataValue1", but instead it logs "Data not Gathered" as if ref.once() never even ran.

Post your code, https://firebase.google.com/docs/database/web/read-and-write#read_data_once worked fine for me. — yuriy636, Aug 08 '17 at 22:31
Try using on, like so: on('value', function(snap){ snap.forEach(function (childsnap){ ...etc — yoursweater, Aug 09 '17 at 01:14
It's asynchronous, so you can't do that: https://stackoverflow.com/q/14220321/6680611 — cartant, Aug 09 '17 at 01:19

score 1 · Accepted Answer · answered Aug 09 '17 at 07:51

since the call to

ref.once("value").then( function(snapshot) { intendedValue = snapshot.val(); });

is basically a callback, so the moment you log the output, the line intendedValue = snapshot.val(); is not even run yet.

You can try this

 ref.once("value").then( function(snapshot) {
  intendedValue = snapshot.val();
  console.log(intendedValue);
});

score -1 · Answer 2 · answered Dec 29 '18 at 17:22

function fire_base_db(){ 

           var ref = firebase.database().ref();
       ref.on("value", function(snapshot) {
console.log(snapshot.val());

}, function (error) {
console.log("Error: " + error.code);
     });}

snapshot.val() contains the value of your databse you can store the value of snapshot.val() in a variable and send it to another function

How to get database information from Firebase database once

2 Answers2