Waiting for firebase storage calls inside an HTTP request to continue

Question

I'm kinda stuck here. I've uploaded some images to my Firebase Storage with unique IDs which I've sent to an external server via HTTP (with a title and such). Now I want to see those images in my phone screen so I have to use HTTP to retrieve the uid's and then search for each image in my storage:

package com.app.chotuve.home

import android.util.Log
import com.app.chotuve.context.ApplicationContext
import com.github.kittinunf.fuel.Fuel
import com.github.kittinunf.fuel.core.extensions.jsonBody
import com.github.kittinunf.fuel.json.responseJson
import com.github.kittinunf.result.Result
import com.google.firebase.storage.FirebaseStorage
import org.json.JSONArray


class VideoDataSource {

    companion object {
        private val TAG: String = "Video Data Source"
        private const val serverURL: String = "https://localhost:8081/videos"
        fun createDataSet(): ArrayList<ModelVideo> {
            val storage = FirebaseStorage.getInstance().reference
            val list = ArrayList<ModelVideo>()
            Fuel.get(serverURL)
                .jsonBody("{ \"user\" : \"${ApplicationContext.getConnectedUsername()}\"," +
                        " \"token\" : \"${ApplicationContext.getConnectedUsername()}\"" +
                        "}") #Ignore this, it is to check if the connected user is valid.
                .responseJson { request, response, result ->
                    when (result) {
                        is Result.Success -> {
                            val body = response.body()
                            val jsonList = JSONArray(body.asString("application/json"))
                            for (i in 0 until jsonList.length()) {
                                val item = jsonList.getJSONObject(i)
                                val date = item["date"] as String
                                val title = item["title"] as String
                                val user = item["user"] as String
                                val thumbURL: String = item["thumbnail"] as String

                                storage.child("thumbnails/").child(thumbURL).downloadUrl
                                    .addOnSuccessListener {
                                        var url = it.toString()
                                        list.add(
                                            ModelVideo(
                                                title,
                                                user,
                                                url,
                                                date
                                            )
                                        )
                                        Log.d(TAG, "Success $url.")
                                    }.addOnFailureListener {
                                        Log.d(TAG, "Error obtaining Video: ${it.message}.")
                                    }
                            }
                        }
                        is Result.Failure -> {
                            //Look up code and choose what to do.
                            Log.d(TAG, "Error obtaining Videos.")
                        }
                    }
                }
            return list
        }
    }
}

Since both Firebase and Fuel are async, the data list is always returned empty and I can't seem to find a way of waiting for the full response.

DISCLAIMER: HTTP is required. I can't move that logic to firebase database (as much as I would want to).

Answer 1

Maybe you can just use blocking HTTP request like this?

...
val list = ArrayList<ModelVideo>()
val (request, response, result) = serverURL.httpGet()
    .jsonBody(
        "{ \"user\" : \"${ApplicationContext.getConnectedUsername()}\"," +
                " \"token\" : \"${ApplicationContext.getConnectedUsername()}\"" +
                "}"
    )
    .responseJson()
when (result) {
...