[AC-6435] Hyperloop object Casting not working on Android

GitHub Issue	n/a
Type	Bug
Priority	n/a
Status	Open
Resolution	Unresolved
Affected Version/s	n/a
Fix Version/s	n/a
Components	Hyperloop
Labels	n/a
Reporter	Gabriel S.
Assignee	Unknown
Created	2019-11-15T14:11:18.000+0000
Updated	2020-01-21T12:24:23.000+0000

Description

I'm trying to use Firebase Firestore (a real-time database) through Hyperloop on Android by using the Firebase SDK. When a Firestore Collection (query) is fetched ^1^, a generic Object is returned. In order to access data stored in this Object we must be able to execute its methods ^2^, such as getDocuments() or be able to iterate over it. As suggested by Hyperloop docs ^3^, the correct procedure is to "Cast" the generic Object in order to access its custom methods and attributes. But the following error shows up when attempting to cast a QuerySnaphot:

HyperloopProxy: (main) [985,7274] Unable to find matching constructor for class: com.google.firebase.firestore.QuerySnapshot, args: [com.google.firebase.firestore.QuerySnapshot@7341330]

Steps to reproduce: Deploy a Firestore instance on Firebase, manually create a collection called "test" and 1 or 2 documents inside it. Install the following package available in the Maven repo using Gradle 'com.google.firebase:firebase-firestore:19.0.2' Then run the following code on a Appcelerator Android app (there are several printouts in order to check the kind of objects we are dealing with):

var FirebaseApp = require('com.google.firebase.FirebaseApp');
var FirebaseOptions = require('com.google.firebase.FirebaseOptions');
var Activity = require('android.app.Activity');
var OnCompleteListener = require('com.google.android.gms.tasks.OnCompleteListener');
var FirebaseFirestore = require('com.google.firebase.firestore.FirebaseFirestore');
var activity = new Activity(Ti.Android.rootActivity);
var builder = new FirebaseOptions.Builder()
              .setApplicationId('Your_ApplicationId')
			        .setApiKey('Your_setApiKey')
				      .setProjectId('Your_ProjectId')
				      .setGcmSenderId('Your_GcmSenderId');

FirebaseApp.initializeApp(
  activity.getApplicationContext(),
  builder.build(),
  'test'
);

var firebaseAppInstance = FirebaseApp.getInstance('test');
var db = FirebaseFirestore.getInstance(firebaseAppInstance);

var docRef = db.collection('test')

docRef.get().addOnCompleteListener(new OnCompleteListener({
	onComplete: function(task) {
    if(task.isSuccessful()) {
      var collection = task.getResult();
      Ti.API.info('collection object');
      Ti.API.info(collection)

      Ti.API.info('collection getOwnPropertyNames');
      Ti.API.info('----------\n');
      Ti.API.info(Object.getOwnPropertyNames(collection));

      Ti.API.info('----------\n');

      Ti.API.info('collection values');
      Ti.API.info(Object.values(collection));

      Ti.API.info('for item in collection');
      for (item in collection) {
        Ti.API.info(item)
      }

      Ti.API.info('----------\n');
      Ti.API.info('collection Array.from');

      var arr = Array.from(collection);

      Ti.API.info('collection for');
        for (var i = 0, j = arr.length; i < j; i++) {
          Ti.API.info(arr[i])
        }

      Ti.API.info('----------\n');

      Ti.API.info('Try casting')
      var QuerySnapshot = require('com.google.firebase.firestore.QuerySnapshot');
      querySnapshot = new QuerySnapshot(collection);

Output:

[INFO] :   ----------
[INFO] :   collection object
[INFO] :   com.google.firebase.firestore.QuerySnapshot@7341330
[INFO] :   collection getOwnPropertyNames
[INFO] :   ----------
[INFO] :   $native,_hasPointer,_private
[INFO] :   ----------
[INFO] :   collection values
[INFO] :   [object Instance],true,[object Object]
[INFO] :   for item in collection
[INFO] :   $native
[INFO] :   _hasPointer
[INFO] :   _private
[INFO] :   className
[INFO] :   getClass
[INFO] :   wait
[INFO] :   hashCode
[INFO] :   equals
[INFO] :   notifyAll
[INFO] :   clone
[INFO] :   toString
[INFO] :   finalize
[INFO] :   notify
[INFO] :   ----------
[INFO] :   collection Array.from
[INFO] :   collection for
[INFO] :   ----------
[INFO] :   Try casting
[ERROR] :  HyperloopProxy: (main) [985,7274] Unable to find matching constructor for class: com.google.firebase.firestore.QuerySnapshot, args: [com.google.firebase.firestore.QuerySnapshot@7341330]

As a workaround, I tried to access the documents inside this collection using 'com.google.common.collect.Lists' (which converts an iterable to a Java array). But the documents are generic Objects as well and the same error shows up when trying to cast them. References: 1 - https://firebase.google.com/docs/firestore/query-data/get-data#get_multiple_documents_from_a_collection 2 - https://firebase.google.com/docs/reference/android/com/google/firebase/firestore/QuerySnapshot 3 - https://wiki.appcelerator.org/display/guides2/Android+Hyperloop+Programming+Guide#AndroidHyperloopProgrammingGuide-Casting

Comments

Gabriel S. 2020-01-21

Shouldn't this issue be assigned to somebody?

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