Modifying transaction null check.

demos/TicTacToe/Classes/AppDelegate.cpp

@@ -10,7 +10,6 @@ const float kFrameHeight = 600;
 AppDelegate::AppDelegate() {}
 
 AppDelegate::~AppDelegate() {}
-
 bool AppDelegate::applicationDidFinishLaunching() {
   auto director = Director::getInstance();
   auto glview = director->getOpenGLView();

demos/TicTacToe/Classes/TicTacToeLayer.cpp

@@ -5,10 +5,6 @@
 #include "firebase/app.h"
 #include "firebase/auth.h"
 #include "firebase/database.h"
-
-using firebase::database::DataSnapshot;
-using firebase::database::MutableData;
-using firebase::database::TransactionResult;
 #include "firebase/future.h"
 #include "firebase/util.h"
 
@@ -23,9 +19,13 @@ using firebase::database::TransactionResult;
 #include <set>
 #include <sstream>
 #include <string>
-using std::string;
 #include <unordered_set>
 
+using firebase::database::DataSnapshot;
+using firebase::database::MutableData;
+using firebase::database::TransactionResult;
+using std::string;
+
 USING_NS_CC;
 
 // Player constants.
@@ -298,7 +298,7 @@ TicTacToeLayer::TicTacToeLayer(string game_uuid) {
   // Sign in using Auth before accessing the database.
   // The default Database permissions allow anonymous users access. This will
   // work as long as your project's Authentication permissions allow anonymous
-  // signin.
+  // sign-in.
   {
     firebase::Future<firebase::auth::User*> sign_in_future =
         auth->SignInAnonymously();
@@ -334,12 +334,14 @@ TicTacToeLayer::TicTacToeLayer(string game_uuid) {
     ref = database->GetReference("game_data").Child(join_game_uuid);
     auto fIncrementTotalUsers = ref.RunTransaction([](MutableData* data) {
       auto total_players = data->Child("total_players").value();
-      if (total_players.type() == NULL) {
-        return TransactionResult::kTransactionResultSuccess;
+      // Completing the transaction based on the returned mutable data value.
+      if (total_players.is_null()) {
+        // Must return this if the transaction was unsuccessful.
+        return TransactionResult::kTransactionResultAbort;
       }
       int new_total_players = total_players.int64_value() + 1;
       if (new_total_players > kNumberOfPlayers) {
-        // Callback function needs to replace Scenes
+        // Must return this if the transaction was unsuccessful.
         return TransactionResult::kTransactionResultAbort;
       }
       data->Child("total_players").set_value(new_total_players);
@@ -514,7 +516,7 @@ void TicTacToeLayer::update(float /*delta*/) {
 }
 
 TicTacToeLayer::~TicTacToeLayer() {
-  // release our sprite and layer so that it gets dealloced
+  // release our sprite and layer so that it gets deallocated
   CC_SAFE_RELEASE_NULL(this->board_sprite);
   CC_SAFE_RELEASE_NULL(this->game_over_label);
   CC_SAFE_RELEASE_NULL(this->waiting_label);

demos/TicTacToe/Classes/TicTacToeLayer.h

@@ -41,7 +41,7 @@ class TicTacToeLayer : public Layer {
   std::string join_game_uuid;
   firebase::database::DatabaseReference ref;
   // Creating listeners for database values.
-  // The databse schema has a top level game_uuid object which includes
+  // The database schema has a top level game_uuid object which includes
   // last_move, total_players and current_player_index fields.
   std::unique_ptr<SampleValueListener> current_player_index_listener;
   std::unique_ptr<SampleValueListener> last_move_listener;

demos/TicTacToe/Classes/TicTacToeScene.cpp

@@ -1,18 +1,18 @@
 #include "TicTacToeScene.h"
 
-// now include our TicTacToeLayer class
 #include "MainMenuScene.h"
 #include "TicTacToeLayer.h"
 #include "cocos2d.h"
 using cocos2d::Scene;
 
-Scene* TicTacToe::createScene(std::string game_uuid) {
+Scene* TicTacToe::createScene(const std::string& game_uuid) {
   // Sets the join_game_uuid to the passed in game_uuid.
   // Builds a simple scene that uses the bottom left cordinate point as (0,0)
   // and can have sprites, labels and layers added onto it.
   Scene* scene = Scene::create();
 
   // Builds a layer to be placed onto the scene which has access to TouchEvents.
+  // This TicTacToe layer being created is owned by scene.
   auto tic_tac_toe_layer = new TicTacToeLayer(game_uuid);
   scene->addChild(tic_tac_toe_layer);
 

demos/TicTacToe/Classes/TicTacToeScene.h

@@ -7,7 +7,7 @@ class TicTacToe : public cocos2d::Layer {
  public:
   // Builds a simple scene that uses the bottom left cordinate point as (0,0)
   // and can have sprites, labels and nodes added onto it.
-  static cocos2d::Scene* createScene(std::string );
+  static cocos2d::Scene* createScene(const std::string&);
   // Defines a create type for a specific type, in this case a Layer.
   CREATE_FUNC(TicTacToe);
 };