Expose MultiDb API (#11365)

* Expose MultiDb API

* Changelog for MultiDb

* Expose MultiDB API

* Pretty

* Add preview comment

Author: tom-andersen

Firestore/CHANGELOG.md

@@ -1,4 +1,5 @@
 # Unreleased
+- [feature] Expose MultiDb API for public preview. (#10465)
 - [fixed] Fixed a compilation warning related to integer casting. (#11332)
 
 # 10.9.0

Firestore/Source/API/FIRFirestore+Internal.h

@@ -83,30 +83,6 @@ NS_ASSUME_NONNULL_BEGIN
 @property(nonatomic, assign, readonly) const model::DatabaseId &databaseID;
 @property(nonatomic, strong, readonly) FSTUserDataReader *dataReader;
 
-/**
- * Creates, caches, and returns named `Firestore` object for the specified `FirebaseApp`. Each
- * subsequent invocation returns the same `Firestore` object.
- *
- * @param app The `FirebaseApp` instance to use for authentication and as a source of the Google
- * Cloud Project ID for your Firestore Database. If you want the default instance, you should
- * explicitly set it to `FirebaseApp.app()`.
- * @param database The database name.
- *
- * @return The named `Firestore` instance.
- */
-+ (instancetype)firestoreForApp:(FIRApp *)app
-                       database:(NSString *)database NS_SWIFT_NAME(firestore(app:database:));
-
-/**
- * Creates, caches, and returns named `Firestore` object for the default _app_. Each subsequent
- * invocation returns the same `Firestore` object.
- *
- * @param database The database name.
- *
- * @return The named `Firestore` instance.
- */
-+ (instancetype)firestoreForDatabase:(NSString *)database NS_SWIFT_NAME(firestore(database:));
-
 @end
 
 NS_ASSUME_NONNULL_END

Firestore/Source/API/FIRFirestore.mm

@@ -166,6 +166,31 @@ - (instancetype)initWithDatabaseID:(model::DatabaseId)databaseID
   return self;
 }
 
++ (instancetype)firestoreForApp:(FIRApp *)app database:(NSString *)database {
+  if (!app) {
+    ThrowInvalidArgument("FirebaseApp instance may not be nil. Use FirebaseApp.app() if you'd like "
+                         "to use the default FirebaseApp instance.");
+  }
+  if (!database) {
+    ThrowInvalidArgument("Database identifier may not be nil. Use '%s' if you want the default "
+                         "database",
+                         DatabaseId::kDefault);
+  }
+
+  id<FSTFirestoreMultiDBProvider> provider =
+      FIR_COMPONENT(FSTFirestoreMultiDBProvider, app.container);
+  return [provider firestoreForDatabase:database];
+}
+
++ (instancetype)firestoreForDatabase:(NSString *)database {
+  FIRApp *app = [FIRApp defaultApp];
+  if (!app) {
+    ThrowIllegalState("Failed to get FirebaseApp instance. Please call FirebaseApp.configure() "
+                      "before using Firestore");
+  }
+  return [self firestoreForApp:app database:database];
+}
+
 - (FIRFirestoreSettings *)settings {
   // Disallow mutation of our internal settings
   return [_settings copy];
@@ -512,31 +537,6 @@ @implementation FIRFirestore (Internal)
   return _firestore->database_id();
 }
 
-+ (instancetype)firestoreForApp:(FIRApp *)app database:(NSString *)database {
-  if (!app) {
-    ThrowInvalidArgument("FirebaseApp instance may not be nil. Use FirebaseApp.app() if you'd like "
-                         "to use the default FirebaseApp instance.");
-  }
-  if (!database) {
-    ThrowInvalidArgument("Database identifier may not be nil. Use '%s' if you want the default "
-                         "database",
-                         DatabaseId::kDefault);
-  }
-
-  id<FSTFirestoreMultiDBProvider> provider =
-      FIR_COMPONENT(FSTFirestoreMultiDBProvider, app.container);
-  return [provider firestoreForDatabase:database];
-}
-
-+ (instancetype)firestoreForDatabase:(NSString *)database {
-  FIRApp *app = [FIRApp defaultApp];
-  if (!app) {
-    ThrowIllegalState("Failed to get FirebaseApp instance. Please call FirebaseApp.configure() "
-                      "before using Firestore");
-  }
-  return [self firestoreForApp:app database:database];
-}
-
 + (FIRFirestore *)recoverFromFirestore:(std::shared_ptr<Firestore>)firestore {
   return (__bridge FIRFirestore *)firestore->extension();
 }

Firestore/Source/Public/FirebaseFirestore/FIRFirestore.h

@@ -62,6 +62,34 @@ NS_SWIFT_NAME(Firestore)
  */
 + (instancetype)firestoreForApp:(FIRApp *)app NS_SWIFT_NAME(firestore(app:));
 
+/**
+ * This method is in preview. API signature and functionality are subject to change.
+ *
+ * Creates, caches, and returns named `Firestore` object for the specified `FirebaseApp`. Each
+ * subsequent invocation returns the same `Firestore` object.
+ *
+ * @param app The `FirebaseApp` instance to use for authentication and as a source of the Google
+ * Cloud Project ID for your Firestore Database. If you want the default instance, you should
+ * explicitly set it to `FirebaseApp.app()`.
+ * @param database The database name.
+ *
+ * @return The named `Firestore` instance.
+ */
++ (instancetype)firestoreForApp:(FIRApp *)app
+                       database:(NSString *)database NS_SWIFT_NAME(firestore(app:database:));
+
+/**
+ * This method is in preview. API signature and functionality are subject to change.
+ *
+ * Creates, caches, and returns named `Firestore` object for the default _app_. Each subsequent
+ * invocation returns the same `Firestore` object.
+ *
+ * @param database The database name.
+ *
+ * @return The named `Firestore` instance.
+ */
++ (instancetype)firestoreForDatabase:(NSString *)database NS_SWIFT_NAME(firestore(database:));
+
 /**
  * Custom settings used to configure this `Firestore` object.
  */