diff --git a/formats/jsonparser.cpp b/formats/jsonparser.cpp
index 01bab27..9de0ea1 100644
--- a/formats/jsonparser.cpp
+++ b/formats/jsonparser.cpp
@@ -26,7 +26,8 @@ QList<QHash<int, QVariant>> JsonParser::toItemValuesList(const QByteArray& jsonD
 QHash<int, QVariant> JsonParser::jsonObjectToItemValues(const QJsonObject& itemJsonObject) {
   QHash<int, QVariant> values;
 
-  // TODO make this more generic (by reading from model meta data)
+  // TODO iterate over "public & editable" roles (the ones that should occur in JSON file)
+  //      & use a (static) function to retrieve it (i. e. getRoleValue(int role))
   values[NameRole]        = itemJsonObject[ROLE_NAMES.value(NameRole)].toString();
   values[DescriptionRole] = itemJsonObject[ROLE_NAMES.value(DescriptionRole)].toString();
   values[InfoRole]        = itemJsonObject[ROLE_NAMES.value(InfoRole)].toString();
diff --git a/genericcore.cpp b/genericcore.cpp
index 3893b9c..86459f5 100644
--- a/genericcore.cpp
+++ b/genericcore.cpp
@@ -12,6 +12,7 @@
 #include "CoreConfig.h"
 #include "constants.h"
 #include "data/filehandler.h"
+#include "model/metadata.h"
 #include "model/tablemodel.h"
 
 #include <QtGui/QUndoStack>
@@ -98,7 +99,7 @@ void GenericCore::saveItems() {
   qDebug() << "saving items...";
 
   const QJsonDocument doc   = m_mainModel->getAllItemsAsJsonDoc();
-  const bool successfulSave = FileHandler::saveToFile(doc, "items.json");
+  const bool successfulSave = FileHandler::saveToFile(doc, ITEM_FILE_NAME);
   if (successfulSave) {
     //    QStringList completedTaskStrings = m_model->completedTasks();
     //    appendCompletedTasksToFile(completedTaskStrings, "completed.txt");
@@ -122,7 +123,7 @@ void GenericCore::setupModels() {
  */
 void GenericCore::initModelData() {
   qInfo() << "Trying to read model data from file...";
-  const QByteArray jsonDoc = FileHandler::loadJSONDataFromFile("items.json");
+  const QByteArray jsonDoc = FileHandler::loadJSONDataFromFile(ITEM_FILE_NAME);
   // qDebug() << "jsonDoc:" << jsonDoc;
   // TODO decide on lack of file(s) (config, data) if example items should be generated
   //      (see welcome wizard)
diff --git a/model/metadata.h b/model/metadata.h
index 76966e9..1c1342a 100644
--- a/model/metadata.h
+++ b/model/metadata.h
@@ -6,15 +6,25 @@
 #include <QList>
 #include <QString>
 
+/// model data
 enum UserRoles { NameRole = Qt::UserRole + 1, DescriptionRole, InfoRole, AmountRole, FactorRole };
 static QHash<int, QByteArray> ROLE_NAMES = {{NameRole, "Name"},
                                             {DescriptionRole, "Description"},
                                             {InfoRole, "Info"},
                                             {AmountRole, "Amount"},
                                             {FactorRole, "Factor"}};
-static QList<QString> intColumns         = {"Amount", "Factor"};
+// TODO ? use a data structure containing the type information of each column
+//      ([QString, QString, QString, int, double], {{NameRole, QString},...})
+//      instead of INT_COLUMNS,...
+static QList<QString> INT_COLUMNS = {"Amount", "Factor"};
 
-static int getRoleForColumn(const int column) {
+/// JSON keys
+static const QString ITEM_KEY_STRING = "items";
+
+/// file naming
+static const QString ITEM_FILE_NAME = ITEM_KEY_STRING + ".json";
+
+static int GET_ROLE_FOR_COLUMN(const int column) {
   switch (column) {
     case 0:
       return NameRole;
diff --git a/model/tablemodel.cpp b/model/tablemodel.cpp
index 057f622..9885a45 100644
--- a/model/tablemodel.cpp
+++ b/model/tablemodel.cpp
@@ -28,7 +28,7 @@ QByteArray TableModel::generateExampleItems() {
 
     array.append(itemObject);
   }
-  rootObject.insert("items", array);
+  rootObject.insert(ITEM_KEY_STRING, array);
 
   doc.setObject(rootObject);
   return doc.toJson();
@@ -65,7 +65,7 @@ QVariant TableModel::data(const QModelIndex& index, int role) const {
     return QVariant();
   }
 
-  int roleForColumn = getRoleForColumn(column);
+  int roleForColumn = GET_ROLE_FOR_COLUMN(column);
   switch (role) {
     case Qt::DisplayRole:
     case Qt::EditRole:
@@ -84,7 +84,7 @@ QVariant TableModel::data(const QModelIndex& index, int role) const {
 QVariant TableModel::headerData(int section, Qt::Orientation orientation, int role) const {
   if (role == Qt::DisplayRole) {
     if (orientation == Qt::Horizontal) {
-      const int columnRole     = getRoleForColumn(section);
+      const int columnRole     = GET_ROLE_FOR_COLUMN(section);
       const QString headerName = ROLE_NAMES.value(columnRole);
       return QString("%1").arg(headerName);
     } else {
@@ -97,7 +97,7 @@ QVariant TableModel::headerData(int section, Qt::Orientation orientation, int ro
 bool TableModel::setData(const QModelIndex& index, const QVariant& value, int role) {
   if (role == Qt::EditRole && checkIndex(index)) {
     const int column        = index.column();
-    const int roleForColumn = getRoleForColumn(column);
+    const int roleForColumn = GET_ROLE_FOR_COLUMN(column);
     return setItemData(index, {{roleForColumn, value}});
   }
   return false;
@@ -129,7 +129,7 @@ QJsonDocument TableModel::getAllItemsAsJsonDoc() const {
     QJsonObject itemObject = item->toJsonObject();
     array.append(itemObject);
   }
-  rootObject.insert("items", array);
+  rootObject.insert(ITEM_KEY_STRING, array);
 
   doc.setObject(rootObject);
   return doc;
@@ -167,7 +167,7 @@ void TableModel::insertItems(int startPosition,
     startPosition = m_items.size();
   }
 
-  QList<QHash<int, QVariant>> valueList = JsonParser::toItemValuesList(jsonDoc, "items");
+  QList<QHash<int, QVariant>> valueList = JsonParser::toItemValuesList(jsonDoc, ITEM_KEY_STRING);
 
   InsertRowsCommand* insertCommand = new InsertRowsCommand(this, startPosition, valueList);
   m_undoStack->push(insertCommand);
@@ -237,7 +237,7 @@ QMap<int, QVariant> TableModel::onlyChangedValues(const QModelIndex& index,
 
 bool TableModel::isEmptyValueEqualToZero(const int role) const {
   const QString roleName = ROLE_NAMES.value(role);
-  if (intColumns.contains(roleName)) {
+  if (INT_COLUMNS.contains(roleName)) {
     return true;
   }
   return false;