Firebase - Cannot read property 'uid' of null

Asked Mar 18 '18 at 16:16

Active Mar 18 '18 at 16:16

Viewed 1,970 times

When I run this code, I get an error Uncaught TypeError: Cannot read property 'uid' of null. Why does this happen? I have some very similar code above it but that runs fine. Here is the error-throwing code:

  function checkForSession(testNo) {
    user = firebase.auth().currentUser;
    firebase.database().ref("users/" + user.uid + "/tests/" + testNo).on('value', function(snapshot) {
        var datas = snapshot.val();
        hour = datas.lastActiveHour;
        minute = datas.lastActiveMinute;
        day = datas.lastActiveDay;
        month = datas.lastActiveMonth;
        year = datas.lastActiveYear;
        pos = datas.position;
        console.log("Last position: " + pos);
    });
  }

asked Mar 18 '18 at 16:16

Benjamin Sommer

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Hi, I think, this should work for you: https://stackoverflow.com/a/37901056/5699040 – Mar 18 '18 at 16:21
I tried putting `userID = firebase.auth().currentUser.uid` in the 'onAuthStateChanged` loop but then I get the error `userID is not defined` – Benjamin Sommer Mar 18 '18 at 16:24
Why is that not working ? – Benjamin Sommer Mar 18 '18 at 16:25
You need to declare your variable like so: `var userId = firebase.auth().currentUser.uid` – Mar 18 '18 at 16:30
I still get the same error. Any ideas on what might be going on? – Benjamin Sommer Mar 18 '18 at 16:45
use this Line `String user = FirebaseAuth.getInstance().getUid();` – Mrunal Mar 18 '18 at 17:14
Still no luck :-( . – Benjamin Sommer Mar 18 '18 at 17:21

Firebase - Cannot read property 'uid' of null

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