Finished isolating firebase logic

app/src/main/java/com/paktalin/vocabularynotebook/firestoreitems/WordItem.kt

 package com.paktalin.vocabularynotebook.firestoreitems
 
-import android.util.Log
-import com.paktalin.vocabularynotebook.appsetup.ConfiguredFirestore
-import com.paktalin.vocabularynotebook.utils.FirestoreManager.Companion.VOCABULARIES
-import com.paktalin.vocabularynotebook.utils.FirestoreManager.Companion.WORDS
+import com.paktalin.vocabularynotebook.utils.FirestoreManager
 import java.io.Serializable
 import java.util.Date
 
@@ -20,10 +17,7 @@ class WordItem(word: String, translation: String, time: Date?, var id: String, p
             : this(pojo.word, pojo.translation, pojo.time, id, vocabularyId)
 
     fun delete() {
-        ConfiguredFirestore.instance.collection(VOCABULARIES).document(vocabularyId)
-                .collection(WORDS).document(id).delete()
-                .addOnSuccessListener { Log.i(TAG, "Successfully deleted word with id $id") }
-                .addOnFailureListener { e -> Log.w(TAG, "deleteWordWithId $id:failure", e.fillInStackTrace()) }
+        FirestoreManager().deleteWord(id)
     }
 
     fun contains(string:String):Boolean {

app/src/main/java/com/paktalin/vocabularynotebook/ui/fragments/VocabularyFragment.kt

@@ -8,15 +8,12 @@ import android.view.View
 import android.view.ViewGroup
 import com.google.firebase.Timestamp
 import com.google.firebase.firestore.DocumentSnapshot
-import com.google.firebase.firestore.Query
 import com.paktalin.vocabularynotebook.*
-import com.paktalin.vocabularynotebook.appsetup.ConfiguredFirestore
 import com.paktalin.vocabularynotebook.firestoreitems.Vocabulary
 import com.paktalin.vocabularynotebook.firestoreitems.WordItem
 import com.paktalin.vocabularynotebook.ui.activities.MainActivity
 import com.paktalin.vocabularynotebook.ui.views.LockableLayoutManager
-import com.paktalin.vocabularynotebook.utils.FirestoreManager.Companion.VOCABULARIES
-import com.paktalin.vocabularynotebook.utils.FirestoreManager.Companion.WORDS
+import com.paktalin.vocabularynotebook.utils.FirestoreManager
 import kotlinx.android.synthetic.main.fragment_vocabulary.*
 
 class VocabularyFragment : Fragment() {
@@ -24,7 +21,6 @@ class VocabularyFragment : Fragment() {
         private val TAG = "VN/" + VocabularyFragment::class.simpleName
     }
 
-    private val db = ConfiguredFirestore.instance
     private lateinit var mainActivity: MainActivity
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
@@ -35,7 +31,7 @@ class VocabularyFragment : Fragment() {
         super.onActivityCreated(savedInstanceState)
         mainActivity = activity as MainActivity
         setEmptyAdapter()
-        retrieveWordsData(arguments!!["vocabularyId"] as String)
+        extractWordsData(arguments!!["vocabularyId"] as String)
     }
 
     private fun setEmptyAdapter() {
@@ -46,17 +42,18 @@ class VocabularyFragment : Fragment() {
         recyclerView.layoutManager = mLayoutManager
     }
 
-    private fun retrieveWordsData(vocabularyId: String) {
-        db.collection(VOCABULARIES).document(vocabularyId).collection(WORDS)
-                .orderBy("time", Query.Direction.DESCENDING)
-                .get()
-                .addOnSuccessListener {
-                    if (it.documents.size != 0)
-                        setVocabularyAdapter(it.documents, vocabularyId)
+    private fun extractWordsData(vocabularyId: String) {
+        FirestoreManager().retrieveWordsData({ documents ->
+            onSuccessfulWordDataExtraction(documents, vocabularyId)}, vocabularyId)
+    }
+
+    private fun onSuccessfulWordDataExtraction(documents: MutableList<DocumentSnapshot>, vocabularyId: String) {
+        if (documents.isNotEmpty())
+            setVocabularyAdapter(documents, vocabularyId)
         else {
             Log.i(TAG, "There are no documents in collection \"words\"")
             mainActivity.showToastNoWords()
-                    }}
+        }
     }
 
     private fun setVocabularyAdapter(documents: MutableList<DocumentSnapshot>, vocabularyId: String) {

app/src/main/java/com/paktalin/vocabularynotebook/utils/FirestoreManager.kt

@@ -6,11 +6,13 @@ import com.google.firebase.auth.FirebaseUser
 import com.google.firebase.firestore.DocumentReference
 import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FirebaseFirestore
+import com.google.firebase.firestore.Query
 import com.paktalin.vocabularynotebook.appsetup.ConfiguredFirestore
 import com.paktalin.vocabularynotebook.firestoreitems.UserPojo
 import com.paktalin.vocabularynotebook.firestoreitems.Vocabulary
 import com.paktalin.vocabularynotebook.firestoreitems.WordItem
 import com.paktalin.vocabularynotebook.ui.activities.LogInActivity
+import com.paktalin.vocabularynotebook.ui.fragments.VocabularyFragment
 import java.util.*
 
 class FirestoreManager {
@@ -74,6 +76,20 @@ class FirestoreManager {
                 }
     }
 
+    fun deleteWord(id: String) {
+        vocabularyDocument(vocabularyId)
+                .collection(WORDS).document(id).delete()
+                .addOnSuccessListener { Log.i(TAG, "Successfully deleted word with id $id") }
+                .addOnFailureListener { e -> Log.w(TAG, "deleteWordWithId $id:failure", e.fillInStackTrace()) }
+    }
+
+    fun retrieveWordsData(onSuccess: (documents: MutableList<DocumentSnapshot>) -> Unit, vocabularyId: String) {
+        vocabularyDocument(vocabularyId).collection(WORDS)
+                .orderBy("time", Query.Direction.DESCENDING)
+                .get()
+                .addOnSuccessListener { onSuccess(it.documents)}
+    }
+
     private fun setNewUserWithVocabularyData(firebaseUser: FirebaseUser,
                                              firstVocabularyRef: DocumentReference,
                                              logInActivity: LogInActivity) {
@@ -99,14 +115,14 @@ class FirestoreManager {
         return db.collection(USERS).document(userId)
     }
 
-    private fun vocabularyDocument(id: String): DocumentReference {
-        return vocabularyCollection.document(id)
+    private fun vocabularyDocument(vocabularyId: String): DocumentReference {
+        return vocabularyCollection.document(vocabularyId)
     }
 
     companion object {
-        const val USERS = "users"
-        const val WORDS = "words"
-        const val VOCABULARIES = "vocabularies"
+        private const val USERS = "users"
+        private const val WORDS = "words"
+        private const val VOCABULARIES = "vocabularies"
         private const val TAG = "VN/FirestoreManager"
 
         lateinit var vocabularyId: String