enh: show only one error when there's a network issue

android/AndroidManifest.xml

 <?xml version="1.0"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="io.qt.qtdesignviewer"
-    android:installLocation="auto" android:versionCode="25" android:versionName="1.2">
+    android:installLocation="auto" android:versionCode="26" android:versionName="1.2">
     <!-- %%INSERT_PERMISSIONS -->
     <!-- %%INSERT_FEATURES -->
     <supports-screens android:anyDensity="true" android:largeScreens="true"

src/backend.cpp

@@ -336,10 +336,12 @@ void Backend::runDemoProject(const QString &projectName)
 
     // sample project info
     // [{"lastUpdate":1701947766739.9812,"name":"ClusterTutorial.qmlrc"}]
-    const std::optional<QJsonArray> projectList = m_serviceConnector.fetchUserDemoList();
+    const std::optional<QJsonArray> projectList = m_serviceConnector.fetchDemoList();
 
     if (projectList == std::nullopt) {
-        qCritical("Please check your internet connection and try again");
+        qCritical(
+            "Could not fetch demo project list. Please check your internet connection and try "
+            "again.");
         emit popupClose();
         return;
     }
@@ -357,9 +359,8 @@ void Backend::runDemoProject(const QString &projectName)
     if (!cached) {
         updatePopup("Downloading demo project...", false);
 
-        const QString url = "https://designviewer.qt.io/qmlprojects/demos/" + projectName
-                            + ".qmlrc";
-        const std::optional<QByteArray> project = m_serviceConnector.fetchProject(url);
+        const std::optional<QByteArray> project = m_serviceConnector.fetchDemo(projectName
+                                                                               + ".qmlrc");
 
         if (project == std::nullopt) {
             qCritical() << "Could not download demo project. Please check the logs for more "
@@ -368,8 +369,6 @@ void Backend::runDemoProject(const QString &projectName)
             return;
         }
 
-        qDebug() << "Demo project is not cached. Trying to download from " << url << " ...";
-
         updatePopup("Caching demo project...");
         if (!m_projectManager->cacheDemoProject(project.value(), projectInfo)) {
             qCritical()
@@ -416,7 +415,8 @@ void Backend::runUserProject(const QString &projectName)
     const std::optional<QJsonArray> projectList = m_serviceConnector.fetchUserProjectList(userHash);
 
     if (projectList == std::nullopt) {
-        qCritical("Please check your internet connection and try again");
+        qCritical("Could not fetch up-to-date project information. Please check your internet "
+                  "connection and try again.");
         emit popupClose();
         return;
     }
@@ -505,8 +505,8 @@ void Backend::updateUserProjectList()
     const std::optional<QJsonArray> projectList = m_serviceConnector.fetchUserProjectList(userHash);
 
     if (projectList == std::nullopt) {
-        qWarning("Could not fetch project list. Either there are no projects or there is a "
-                 "network issue");
+        qWarning(
+            "Could not fetch project list. Please check your internet connection and try again.");
     } else if (projectList.value() == m_projectList) {
         qDebug("No new projects are available");
     } else {

src/serviceConnector.cpp

@@ -31,7 +31,7 @@
 #include <QJsonDocument>
 #include <QJsonObject>
 
-QByteArray ServiceConnector::fetchResource(const QString &url, const bool quite)
+std::optional<QByteArray> ServiceConnector::fetchResource(const QString &url)
 {
     qDebug() << "Fetching resource from" << url;
 
@@ -42,10 +42,7 @@ QByteArray ServiceConnector::fetchResource(const QString &url, const bool quite)
                      &QNetworkReply::sslErrors,
                      this,
                      [&](const QList<QSslError> &errors) {
-                         if (!quite)
-                             qCritical() << errors.first().errorString();
-                         else
-                             qWarning() << errors.first().errorString();
+                         qWarning() << errors.first().errorString();
                      });
 
     QEventLoop loop;
@@ -63,56 +60,42 @@ QByteArray ServiceConnector::fetchResource(const QString &url, const bool quite)
     loop.exec();
 
     if (reply->error() != QNetworkReply::NoError) {
-        if (!quite)
-            qCritical() << reply->errorString();
-        else
-            qWarning() << reply->errorString();
-    } else {
-        qDebug() << "Resource fetched successfully";
+        qWarning() << reply->errorString();
+        return {};
     }
 
+    qDebug() << "Resource fetched successfully";
     return reply->readAll();
 }
 
 std::optional<QByteArray> ServiceConnector::fetchProject(const QString &url)
 {
     QString projectUrl = url;
-    if (projectUrl.startsWith("https://designviewer.qt.io/#"))
-    {
+    if (projectUrl.startsWith(m_serviceUrl + "/#")) {
         projectUrl = projectUrl.split("#").at(1);
-        projectUrl.prepend("https://designviewer.qt.io/qmlprojects/");
+        projectUrl.prepend(m_serviceUrl + "/qmlprojects/");
     }
 
-    auto reply = fetchResource(projectUrl);
-    if (reply.size() == 0)
-        return {};
-
-    return reply;
+    return fetchResource(projectUrl);
 }
 
 std::optional<QByteArray> ServiceConnector::fetchUserProject(const QString &userHash,
                                                              const QString &projectName)
 {
-    const QString projectUrl = "https://designviewer.qt.io/qmlprojects/" + userHash + "/"
-                               + projectName + ".qmlrc";
-
-    auto reply = fetchResource(projectUrl);
-    if (reply.size() == 0)
-        return {};
+    const QString projectUrl = m_serviceUrl + "/qmlprojects/" + userHash + "/" + projectName
+                               + ".qmlrc";
 
-    return reply;
+    return fetchResource(projectUrl);
 }
 
 std::optional<QJsonArray> ServiceConnector::fetchUserProjectList(const QString &userHash)
 {
-    auto reply = fetchResource("https://designviewer.qt.io/api/v1/qmlrc/list/" + userHash
-                                   + "?key=818815",
-                               true);
+    auto reply = fetchResource(m_serviceUrl + "/api/v1/qmlrc/list/" + userHash + "?key=818815");
 
-    if (reply.size() == 0)
+    if (!reply)
         return {};
 
-    QJsonArray projectList = QJsonDocument::fromJson(reply)
+    QJsonArray projectList = QJsonDocument::fromJson(reply.value())
                                  .object()
                                  .value("data")
                                  .toObject()
@@ -122,11 +105,16 @@ std::optional<QJsonArray> ServiceConnector::fetchUserProjectList(const QString &
     return projectList;
 }
 
-std::optional<QJsonArray> ServiceConnector::fetchUserDemoList()
+std::optional<QJsonArray> ServiceConnector::fetchDemoList()
 {
-    auto reply = fetchResource("https://designviewer.qt.io/api/v1/demos");
-    if (reply.size() == 0)
+    auto reply = fetchResource(m_serviceUrl + "/api/v1/demos");
+    if (!reply)
         return {};
 
-    return QJsonDocument::fromJson(reply).array();
+    return QJsonDocument::fromJson(reply.value()).array();
+}
+
+std::optional<QByteArray> ServiceConnector::fetchDemo(const QString &demoName)
+{
+    return fetchResource(m_serviceUrl + "/qmlprojects/demos/" + demoName + ".qmlrc");
 }

src/serviceConnector.h

@@ -36,11 +36,14 @@ public:
     std::optional<QByteArray> fetchProject(const QString &url);
     std::optional<QByteArray> fetchUserProject(const QString &userHash, const QString &projectName);
     std::optional<QJsonArray> fetchUserProjectList(const QString &userHash);
-    std::optional<QJsonArray> fetchUserDemoList();
+    std::optional<QJsonArray> fetchDemoList();
+    std::optional<QByteArray> fetchDemo(const QString &demoName);
 
 private:
     QNetworkAccessManager m_manager;
-    QByteArray fetchResource(const QString &url, const bool quite = false);
+    std::optional<QByteArray> fetchResource(const QString &url);
+
+    const QString m_serviceUrl = "https://designviewer.qt.io";
 
 signals:
     void downloadProgress(float percentage);