void AddDataTransactions()

in firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp [342:377]

• 27 lines of code
• 2 McCabe index (conditional complexity)

void AddDataTransactions(firebase::firestore::Firestore* db) {
  using firebase::Future;
  using firebase::firestore::DocumentReference;
  using firebase::firestore::DocumentSnapshot;
  using firebase::firestore::Error;
  using firebase::firestore::FieldValue;
  using firebase::firestore::Transaction;

  // The following example shows how to create and run a transaction:
  // [START simple_transaction]
  DocumentReference sf_doc_ref = db->Collection("cities").Document("SF");
  db->RunTransaction([sf_doc_ref](Transaction& transaction,
                                  std::string& out_error_message) -> Error {
      Error error = Error::kErrorOk;

      DocumentSnapshot snapshot =
          transaction.Get(sf_doc_ref, &error, &out_error_message);

      // Note: this could be done without a transaction by updating the
      // population using FieldValue::Increment().
      std::int64_t new_population =
          snapshot.Get("population").integer_value() + 1;
      transaction.Update(
          sf_doc_ref,
          {{"population", FieldValue::Integer(new_population)}});

      return Error::kErrorOk;
    }).OnCompletion([](const Future<void>& future) {
    if (future.error() == Error::kErrorOk) {
      std::cout << "Transaction success!" << std::endl;
    } else {
      std::cout << "Transaction failure: " << future.error_message() << std::endl;
    }
  });
  // [END simple_transaction]
}