Cannot setInt nor save PlayerPrefs when retrieving entries from Realtime Database - Silent fail

[michelepanegrossi]

Please fill in the following fields:

Unity editor version: 2019.4.6.f
Firebase Unity SDK version: 6.15.2
Source you installed the SDK (.unitypackage or Unity Package Manager): .unitypackage
Firebase plugins in use (Auth, Database, etc.): Realtime Database
Additional SDKs you are using (Facebook, AdMob, etc.): None
Platform you are using the Unity editor on (Mac, Windows, or Linux): Mac
Platform you are targeting (iOS, Android, and/or desktop): Android
Scripting Runtime (Mono, and/or IL2CPP): IL2CPP

Please describe the issue here:

(Please list the full steps to reproduce the issue. Include device logs, Unity logs, and stack traces if available.)

I am succesfully retrieveing data from the database. However, when I try to set an int value in the PlayerPrefs, the script 'stops' and silently fails without returning any errors.

This is the code I am using, I am calling this method with a button:

    public void RetrieveCodes()
    {
        _codeFromUser = _codeInputField.text;

        FirebaseDatabase.DefaultInstance.GetReference("SH_TT").GetValueAsync().ContinueWith(retrieveTask => {
            if (retrieveTask.IsFaulted)
            {
                Debug.Log("No snapshot");
                // Handle the error...
            }
            else if (retrieveTask.IsCompleted)
            {
                DataSnapshot snapshot = retrieveTask.Result;

                foreach (DataSnapshot ds in snapshot.Children)
                {
                 
                    Debug.Log(ds.ChildrenCount);

                    _currentOrder = new Order(ds.Key, ds.Child("Date").Value.ToString(),ds.Child("Email").Value.ToString(), ds.Child("OrderID").Value.ToString(), ds.Child("Redeemed").Value.ToString());

                    _ordersList.Add(_currentOrder);

                    Debug.Log($"_Coderedeemed:= {ds.Key}");
                    Debug.Log($"_Coderedeemed:= {_currentOrder.OrderID}");
                }

                //RETRIEVEAL FINISHED
                //DO STUFF
                foreach(Order o in _ordersList)
                {
                    if (o.OrderID == _codeFromUser)
                    {
                        if (o.Redeemed == "N")
                        {
                            Debug.Log($"Event Date: {o.Date}");
                            reference.Child("SH_TT").Child(o.OrderKey).Child("Redeemed").SetValueAsync("Y");
                            Debug.Log("FOUND TICKET"); //THIS IS THE LAST EXECUTED INSTRUCTION, NOTHING AFTER THIS HAPPENS
                            PlayerPrefs.SetInt("HasRedeemedShow", 1);
                            PlayerPrefs.Save();
                            Debug.Log("SAVED PLAYER");
                        }
                        else
                        {
                            Debug.Log("Ticket Has Already Been redeemed!!!");
                        }
                    }
                }
            }
        });
    }

The last line which is executed is Debug.Log("FOUND TICKET"); , nothing is executed after that. However, if I remove the lines PlayerPrefs.SetInt("HasRedeemedShow", 1); and PlayerPrefs.Save(); then the line Debug.Log("SAVED PLAYER"); is executed.

No errors appear in the Console. I don't understand what is going on! Any help would be appreciated!

Please answer the following, if applicable:

Have you been able to reproduce this issue with just the Firebase Unity quickstarts (this GitHub project)?

N/A

What's the issue repro rate? (eg 100%, 1/5 etc)

100%

[michelepanegrossi]

This keeps happening with different instructions as well. For instance _redeemButton.SetActive(true); is not executed. The instruction _redeemedText.color = Color.green;. is executed but the line _redeemedText.text = ticketFound; is not executed.

So far the only instructions I can execute in that postion of the script include:

• Variable assign
• Debug.Log
• Change colour of a Text component

This is the block of code I am trying to execute, I changed it slightly from the previous post:

public void RetrieveCodes()
    {
        _codeFromUser = _codeInputField.text;
        Debug.Log(_codeInputField.text);
        Debug.Log(_codeFromUser);

        FirebaseDatabase.DefaultInstance.GetReference("SH_TT").GetValueAsync().ContinueWith(retrieveTask =>
        {
            if (retrieveTask.IsFaulted)
            {
                Debug.Log("No snapshot");
                // Handle the error...
            }
            else if (retrieveTask.IsCompleted)
            {
                DataSnapshot snapshot = retrieveTask.Result;

                foreach (DataSnapshot ds in snapshot.Children)
                {
                    _currentOrder = new Order(ds.Key, ds.Child("Date").Value.ToString(), ds.Child("Email").Value.ToString(), ds.Child("OrderID").Value.ToString(), ds.Child("Redeemed").Value.ToString());

                    _ordersList.Add(_currentOrder);

                    Debug.Log($"_Coderedeemed:= {ds.Key}");
                    Debug.Log($"_Coderedeemed:= {_currentOrder.OrderID}");

                }

                //RETRIEVEAL FINISHED
                //DO STUFF
                foreach (Order o in _ordersList)
                {
                    if (o.OrderID == _codeFromUser)
                    {
                        if (o.Redeemed == "N")
                        {
                           //THIS BLOCK HERE WORKS FINE
                            _hasFoundTicket = true;
                            _theEventDateString = o.Date;
                            _theEventOrderID = o.OrderID;
                            _theEventKeyId = o.OrderKey;
                            Debug.Log($"Retrieved Event Date: {_theEventDateString} from database");
                            Debug.Log($"Retrieved Event Ticket Code: {_theEventOrderID} from database");
                            Debug.Log($"Retrieved Event Order ID: {_theEventKeyId} from database");

                        }
                        else
                        {
                            Debug.Log("Ticket Has Already Been redeemed!!!");
                            //THIS BLOCK DOWN HERE DOESN'T WORK
                            _redeemedText.color = Color.yellow;
                            _redeemedText.text = "This ticket has alrady been redeemed!!!";
                        }
                    }

                }

                if (_hasFoundTicket == false)
                {
                    Debug.Log("Ticket NOT FOUND!!!");
                    //THIS BLOCK DOWN HERE DOESN'T WORK
                    _redeemedText.color = Color.red;
                    _redeemedText.text = ticketnotFound;
                }
                else
                {
                    //THIS BLOCK HERE DOESN'T WORK
                    Debug.Log("Ticket FOUND!!!");
                    _redeemedText.color = Color.green; //THIS IS THE LAST LINE WHICH IS EXECUTED
                    //THESE LINES ARE NOT EXECUTED, WHY????
                    Debug.Log("I am here");
                    _redeemedText.text = ticketFound;
                    Debug.Log("I am here2");
                    _redeemButton.SetActive(true);
                    Debug.Log("I am here3");

                }
            }
        
        });
    }

What is going on??

[vimanyu]

Hi @michelepanegrossi,
I suspect the issue is how asynchronous tasks are queued up in Unity.
https://firebase.googleblog.com/2019/07/firebase-and-tasks-how-to-deal-with.html

Maybe try with ContinueWithOnMainThread instead of ContinueWith?

Let us know if this solution works for you.

[michelepanegrossi]

Thanks @vimanyu, using ContinueWithOnMainThread instead of ContinueWith solved the issue!

Thank you for pointing me towards that blog post, it is extremely useufl and fascinating!

I only have one question / concern. Will using ContinueWithOnMainThread block the execution of the main thread until all entries from the database have been rerieved and could this become an issue when there are a lot of entries to retrieve?

Many thanks

[vimanyu]

I am glad that this solved the issue.
If you are using ContinueWithOnMainThread, Firebase I/O is still happening asynchronously. Once the I/O is done, the continuation happens on the main thread to play nicely with shared resources in Unity. So, the fetching from the database should be fine (and ofcourse the fetch time is dependent on how many entries are there in the DB), but the main thread gets busy only when the fetch is complete.
I am going to close this ticket as we have a solve for the original issue.