Basic JSON RESTful client fetching items from a local server at application start and adding them to the model.

CMakeLists.txt

@@ -12,6 +12,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 find_package(QT NAMES Qt6 REQUIRED COMPONENTS Core LinguistTools)
 find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Core LinguistTools Gui)
 find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Test)
+find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Network)
 
 configure_file(CoreConfig.h.in CoreConfig.h)
 
@@ -32,16 +33,18 @@ add_library(${TARGET_APP} STATIC
   data/filehandler.h data/filehandler.cpp
   model/metadata.h
   formats/csvparser.h formats/csvparser.cpp
+  model/generalsortfiltermodel.h model/generalsortfiltermodel.cpp
+  network/servercommunicator.h network/servercommunicator.cpp
+  network/apiroutes.h
   # 3rd party libraries
   ../3rdParty/rapidcsv/src/rapidcsv.h
-  model/generalsortfiltermodel.h model/generalsortfiltermodel.cpp
 )
 
-
-target_link_libraries(GenericCore PRIVATE Qt${QT_VERSION_MAJOR}::Test)
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
 target_link_libraries(${TARGET_APP} PRIVATE Qt${QT_VERSION_MAJOR}::Core Qt${QT_VERSION_MAJOR}::Gui)
+target_link_libraries(GenericCore PRIVATE Qt${QT_VERSION_MAJOR}::Test)
+target_link_libraries(GenericCore PRIVATE Qt${QT_VERSION_MAJOR}::Network)
 
 target_compile_definitions(${TARGET_APP} PRIVATE ${TARGET_APP}_LIBRARY)
 

genericcore.cpp

@@ -16,6 +16,7 @@
 #include "model/generalsortfiltermodel.h"
 #include "model/metadata.h"
 #include "model/tablemodel.h"
+#include "network/servercommunicator.h"
 
 #include <QtGui/QUndoStack>
 
@@ -37,6 +38,7 @@ GenericCore::GenericCore() {
   m_modelUndoStack = new QUndoStack(this);
 
   setupModels();
+  setupServerConfiguration();
 }
 
 GenericCore::~GenericCore() { qDebug() << "Destroying core..."; }
@@ -132,6 +134,32 @@ bool GenericCore::exportCSVFile(const QString& filePath) {
   return FileHandler::exportToCSVFile(itemsAsStringLists, filePath);
 }
 
+bool GenericCore::isSyncServerSetup() const {
+  if (m_serverCommunicator) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void GenericCore::onItemsFetched(const QByteArray jsonDoc) {
+  emit displayStatusMessage("New items fetched.");
+  // TODO ? check compability of JSON structure beforehand?
+  m_mainModel->appendItems(jsonDoc);
+}
+
+void GenericCore::onItemsFetchFailure(const QString errorString) {
+  emit displayStatusMessage(QString("Error: %1").arg(errorString));
+}
+
+void GenericCore::onPostRequestSuccessful(const QString message) {
+  emit displayStatusMessage(message);
+}
+
+void GenericCore::onPostRequestFailure(const QString errorString) {
+  emit displayStatusMessage(QString("Error: %1").arg(errorString));
+}
+
 void GenericCore::setupModels() {
   m_mainModel       = make_shared<TableModel>(m_modelUndoStack, this);
   m_sortFilterModel = make_shared<GeneralSortFilterModel>(m_mainModel);
@@ -188,3 +216,19 @@ QString GenericCore::getMaintenanceToolFilePath() const {
   const QString filePath = applicationDirPath + "/" + UPDATER_EXE;
   return filePath;
 }
+
+void GenericCore::setupServerConfiguration() {
+  m_serverCommunicator = make_unique<ServerCommunicator>(this);
+
+  connect(m_serverCommunicator.get(), &ServerCommunicator::itemsFetched, this,
+          &GenericCore::onItemsFetched);
+  connect(m_serverCommunicator.get(), &ServerCommunicator::itemsFetchFailure, this,
+          &GenericCore::onItemsFetchFailure);
+  connect(m_serverCommunicator.get(), &ServerCommunicator::postRequestSuccessful, this,
+          &GenericCore::onPostRequestSuccessful);
+  connect(m_serverCommunicator.get(), &ServerCommunicator::postRequestFailure, this,
+          &GenericCore::onPostRequestFailure);
+
+  /// fetching items on startup to test the communication with the server
+  m_serverCommunicator->fetchItems();
+}

genericcore.h

@@ -10,6 +10,7 @@ class QString;
 
 class TableModel;
 class GeneralSortFilterModel;
+class ServerCommunicator;
 
 class GenericCore : public QObject {
   Q_OBJECT
@@ -32,6 +33,14 @@ class GenericCore : public QObject {
   void importCSVFile(const QString& filePath);
   bool exportCSVFile(const QString& filePath);
 
+  bool isSyncServerSetup() const;
+
+ public slots:
+  void onItemsFetched(const QByteArray jsonDoc);
+  void onItemsFetchFailure(const QString errorString);
+  void onPostRequestSuccessful(const QString message);
+  void onPostRequestFailure(const QString errorString);
+
  signals:
   void displayStatusMessage(QString message);
 
@@ -46,6 +55,10 @@ class GenericCore : public QObject {
   void initModelData();
 
   QString getMaintenanceToolFilePath() const;
+
+  /// Network communication
+  std::unique_ptr<ServerCommunicator> m_serverCommunicator;
+  void setupServerConfiguration();
 };
 
 #endif  // GENERICCORE_H

model/metadata.h

@@ -6,6 +6,8 @@
 #include <QList>
 #include <QString>
 
+// TODO add namespace
+
 /// model data
 enum UserRoles {
   NameRole = Qt::UserRole + 1,
@@ -16,6 +18,7 @@ enum UserRoles {
   /// helper roles
   ToStringRole
 };
+
 static UserRoles DEFAULT_ROLE             = NameRole;
 static QList<UserRoles> USER_FACING_ROLES = {NameRole, DescriptionRole, InfoRole, AmountRole,
                                              FactorRole};

model/tablemodel.cpp

@@ -193,6 +193,12 @@ void TableModel::insertItems(int startPosition,
                              const QModelIndex& parentIndex) {
   const QList<ModelItemValues> valueList = JsonParser::toItemValuesList(jsonDoc, ITEM_KEY_STRING);
 
+  if (valueList.empty()) {
+    /// don't try inserting if no values to insert
+    qDebug() << "No items found in JSON document. Not adding anything...";
+    return;
+  }
+
   insertItems(startPosition, valueList, parentIndex);
 }
 

network/apiroutes.h

@@ -0,0 +1,13 @@
+#ifndef APIROUTES_H
+#define APIROUTES_H
+
+#include <QString>
+
+// TODO add namespace
+
+static const QString baseUrl   = "http://127.0.0.1:4000";
+static const QString apiPrefix = "/api/";
+
+static const QString ROUTE_ITEMS = apiPrefix + "items";
+
+#endif  // APIROUTES_H

network/servercommunicator.cpp

@@ -0,0 +1,60 @@
+#include "servercommunicator.h"
+#include "apiroutes.h"
+
+#include <QJsonArray>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QRestReply>
+
+using namespace Qt::StringLiterals;
+
+ServerCommunicator::ServerCommunicator(QObject* parent)
+    : QObject{parent} {
+  m_netManager.setAutoDeleteReplies(true);
+  m_restManager = std::make_shared<QRestAccessManager>(&m_netManager);
+  m_serviceApi  = std::make_shared<QNetworkRequestFactory>();
+  setUrl(baseUrl);
+}
+
+bool ServerCommunicator::sslSupported() {
+#if QT_CONFIG(ssl)
+  return QSslSocket::supportsSsl();
+#else
+  return false;
+#endif
+}
+
+QUrl ServerCommunicator::url() const { return m_serviceApi->baseUrl(); }
+
+void ServerCommunicator::setUrl(const QUrl& url) {
+  if (m_serviceApi->baseUrl() == url) {
+    return;
+  }
+  m_serviceApi->setBaseUrl(url);
+  QHttpHeaders authenticationHeaders;
+  m_serviceApi->setCommonHeaders(authenticationHeaders);
+  emit urlChanged();
+}
+
+void ServerCommunicator::fetchItems() {
+  /// Set up a GET request
+  m_restManager->get(m_serviceApi->createRequest(ROUTE_ITEMS), this, [this](QRestReply& reply) {
+    if (reply.isSuccess()) {
+      qInfo() << "Fetching items successful.";
+      const QJsonDocument doc = reply.readJson().value();
+      emit itemsFetched(doc.toJson());
+
+    } else {
+      if (reply.hasError()) {
+        const QString errorString = reply.errorString();
+        qCritical() << "ERROR:" << errorString;
+        emit itemsFetchFailure(errorString);
+      } else {
+        int statusCode = reply.httpStatus();
+        qCritical() << "ERROR:" << statusCode;
+        emit itemsFetchFailure(QString::number(statusCode));
+        emit itemsFetchFailure(QString("HTTP status code: %1").arg(statusCode));
+      }
+    }
+  });
+}

network/servercommunicator.h

@@ -0,0 +1,33 @@
+#ifndef SERVERCOMMUNICATOR_H
+#define SERVERCOMMUNICATOR_H
+
+#include <QNetworkAccessManager>
+#include <QNetworkRequestFactory>
+#include <QObject>
+#include <QRestAccessManager>
+
+class ServerCommunicator : public QObject {
+  Q_OBJECT
+ public:
+  explicit ServerCommunicator(QObject* parent = nullptr);
+
+  bool sslSupported();
+
+  QUrl url() const;
+  void setUrl(const QUrl& url);
+
+  void fetchItems();
+
+ signals:
+  void urlChanged();
+
+  void itemsFetched(const QByteArray jsonDoc);
+  void itemsFetchFailure(const QString errorString);
+
+ private:
+  QNetworkAccessManager m_netManager;
+  std::shared_ptr<QRestAccessManager> m_restManager;
+  std::shared_ptr<QNetworkRequestFactory> m_serviceApi;
+};
+
+#endif  // SERVERCOMMUNICATOR_H