Merge pull request #15 from ofalvai/observable-add

Adding documents with Single<DocumentReference> besides Completable

publishing-config.gradle

@@ -1,7 +1,7 @@
 ext.artifactInfo = [
   // Publishing
-  libraryVersion : '1.1.1',
-  libraryVersionName : '1.1.1',
+  libraryVersion : '1.2.0',
+  libraryVersionName : '1.2.0',
   bintrayRepo : 'maven',
   publishedGroupId : 'com.oakwoodsc.rxfirestore',
   libraryDescription : 'An RxJava2 wrapper for Cloud Firestore',

rxfirestore/src/main/java/com/oakwoodsc/rxfirestore/AddOnSubscribe.java

@@ -1,20 +1,20 @@
 package com.oakwoodsc.rxfirestore;
 
 import android.support.annotation.NonNull;
-
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
 import com.google.firebase.firestore.CollectionReference;
 import com.google.firebase.firestore.DocumentReference;
-
 import io.reactivex.CompletableEmitter;
 import io.reactivex.CompletableOnSubscribe;
+import io.reactivex.SingleEmitter;
+import io.reactivex.SingleOnSubscribe;
 
 /**
  * Created by Brandon Trautmann
  */
 
-public class AddOnSubscribe<T> implements CompletableOnSubscribe {
+public class AddOnSubscribe<T> implements CompletableOnSubscribe, SingleOnSubscribe<DocumentReference> {
 
   private final CollectionReference reference;
   private final T value;
@@ -44,4 +44,23 @@ public void onComplete(@NonNull Task<DocumentReference> task) {
 
     reference.add(value).addOnCompleteListener(listener);
   }
+
+  @Override
+  public void subscribe(final SingleEmitter<DocumentReference> emitter) throws Exception {
+    final OnCompleteListener<DocumentReference> listener =
+        new OnCompleteListener<DocumentReference>() {
+          @Override
+          public void onComplete(@NonNull Task<DocumentReference> task) {
+            if (!emitter.isDisposed()) {
+              if (!task.isSuccessful()) {
+                emitter.onError(task.getException());
+              } else {
+                emitter.onSuccess(task.getResult());
+              }
+            }
+          }
+        };
+
+    reference.add(value).addOnCompleteListener(listener);
+  }
 }

rxfirestore/src/main/java/com/oakwoodsc/rxfirestore/RxFirestoreDb.java

@@ -2,7 +2,6 @@
 
 import android.support.annotation.CheckResult;
 import android.support.annotation.NonNull;
-
 import com.google.firebase.firestore.CollectionReference;
 import com.google.firebase.firestore.DocumentChange;
 import com.google.firebase.firestore.DocumentReference;
@@ -12,14 +11,13 @@
 import com.google.firebase.firestore.QuerySnapshot;
 import com.google.firebase.firestore.Transaction;
 import com.google.firebase.firestore.WriteBatch;
-
-import java.util.Map;
-import java.util.concurrent.Executor;
-
 import io.reactivex.Completable;
 import io.reactivex.Observable;
 import io.reactivex.Single;
 
+import java.util.Map;
+import java.util.concurrent.Executor;
+
 /**
  * The main class used to interact with Cloud Firestore
  */
@@ -211,6 +209,23 @@ public static <T> Completable add(@NonNull CollectionReference reference, T valu
     return Completable.create(new AddOnSubscribe<>(reference, value));
   }
 
+  /**
+   * Adds a document at the given {@link CollectionReference}, then returns its {@link DocumentReference}. This is
+   * useful when the auto-generated ID of the new document is needed.
+   * <p>
+   * Note, this is a <b>blocking</b> call because of how Firestore handles offline persistence.
+   * That means the onComplete() callback will not be called if the user is offline, so it is recommended
+   * not to block the UI until this completes
+   *
+   * @param reference the {@link CollectionReference} at which to add the document
+   * @return {@link Single}
+   */
+  @NonNull
+  @CheckResult
+  public static <T> Single<DocumentReference> addAndProvideDocId(@NonNull CollectionReference reference, T value) {
+    return Single.create(new AddOnSubscribe<>(reference, value));
+  }
+
   /**
    * Runs a {@link Transaction} (series of reads and writes) for the given {@link FirebaseFirestore}
    * instance

rxfirestorekt/src/main/java/com/oakwoodsc/rxfirestorekt/RxFirestoreDb.kt

@@ -39,6 +39,9 @@ fun DocumentReference.deleteDoc(): Completable =
 fun <T> CollectionReference.addDoc(value: T): Completable =
   RxFirestoreDb.add(this, value)
 
+fun <T> CollectionReference.addDocAndProvideId(value: T): Single<DocumentReference> =
+  RxFirestoreDb.addAndProvideDocId(this, value)
+
 fun <T> FirebaseFirestore.run(transaction: Transaction.Function<T>)
   : Completable = RxFirestoreDb.runTransaction(this, transaction)