How to connect to Firebase Database using sj-firebase-python 1.0.1

[hardikfuria12]

Wondering how to connect to Firebase Realtime Database using sj-firebase-python. I have been trying to connect using the documentation, but unable to do so.

What I am trying to do?
When user presses a dropdown menu show him a list of customers. This list is present in the Firebase Realtime Database, I want to populate this list in my dropdown menu.

I have been following the mvc4kivy framework. For simplicity and testing I am writing the code in controller code itself

My Control Code looks like

def get_list(self):
        list = self.model.database.firebase_database.get_ref("customers")

where firebase_database is SJFirebaseDatabase object. and customers is a document under https://project-url.asia-southeast1.firebasedatabase.app/

But when I run it on my andorid phone i get the following error.

File "jnius/jnius_export_class.pxi", line 846, in jnius.jnius.JavaMethod.__call__jnius.jnius.JavaException: Invalid call, number of argument mismatch, got 1 need 0, found definitions () in class b'com/simplejnius/sjfirebase/SJFirebaseDatabase' method b'get_ref'

Then I tried using the getInstance,

def get_list(self):
        list = self.model.database.firebase_database.get_instance().get_ref("customers")

here it shows that this object does not have the method get_instance

Am I missing something?
Kindly help

[kengoon]

@hardikfuria12 So the reason you are having that error is that get_ref does not accept any argument. I would have to update the code to make it accept arguments because it has multiple method mode (arguments and no arguments) on the java sdk side.

here is a quick fix to your problem

def get_list(self):
        list = self.model.database.firebase_database.get_ref().child("customer")

The reason you had the secon error was because SJFirebaseDatabase does not have the get_instance method. here is the source code with only 2 methods in it

sj-firebase-python/sjfirebase/jclass/database.py

Lines 7 to 10 in e2b9ac6

	class SJFirebaseDatabase(JavaClass, metaclass=MetaJavaClass):
	__javaclass__ = f"{package_path}SJFirebaseDatabase"
	get_db = JavaStaticMethod("()Lcom/google/firebase/database/FirebaseDatabase;")
	get_ref = JavaStaticMethod("()Lcom/google/firebase/database/DatabaseReference;")

You can use get_db to access get_ref

https://github.com/SimpleJnius/sj-firebase-java/blob/3dea4f7decd619e9427e46e65ceaa9671eaad9c0/sjfirebase/src/main/java/com/simplejnius/sjfirebase/SJFirebaseDatabase.java#L6-L14

I would further advice you move the get list code into model instead of controller and then do something like this from controller

self.model.get_list(callback=self.callback)