Show warning if no report title

App.axaml

@@ -97,6 +97,9 @@
         <DataTemplate DataType="{x:Type viewModels:AboutViewModel}">
             <views:AboutView/>
         </DataTemplate>
+        <DataTemplate DataType="{x:Type viewModels:WarningViewModel}">
+            <views:WarningView/>
+        </DataTemplate>
     </Application.DataTemplates>
     <Application.Resources>
         <ResourceDictionary>

ViewModels/MainViewModel.cs

@@ -206,23 +206,30 @@ class MainViewModel : BaseViewModel, IFontResolver
 
     public async void BuildPDF()
     {
-        try
+        if (string.IsNullOrWhiteSpace(ReportTitle))
         {
-            // TODO: use already found files and information
-            await Task.Run(() => CreatePDF(_workingFolder));
-        } catch (Exception e)
+            await DialogHost.Show(new WarningViewModel("You must provide a report title!"));
+        }
+        else
         {
-            LogInfo("PDF process failed! Reason: " + e.Message);
-            if (e.StackTrace != null)
+            try
             {
-                LogInfo(e.StackTrace);
-            }
-            if (e.InnerException != null)
+                // TODO: use already found files and information
+                await Task.Run(() => CreatePDF(_workingFolder));
+            } catch (Exception e)
             {
-                LogInfo("Inner exception: " + e.InnerException.Message);
-                if (e.InnerException.StackTrace != null)
+                LogInfo("PDF process failed! Reason: " + e.Message);
+                if (e.StackTrace != null)
                 {
-                    LogInfo(e.InnerException.StackTrace);
+                    LogInfo(e.StackTrace);
+                }
+                if (e.InnerException != null)
+                {
+                    LogInfo("Inner exception: " + e.InnerException.Message);
+                    if (e.InnerException.StackTrace != null)
+                    {
+                        LogInfo(e.InnerException.StackTrace);
+                    }
                 }
             }
         }

Views/WarningView.axaml

@@ -10,16 +10,20 @@
              x:DataType="vm:WarningViewModel">
     <StackPanel Orientation="Vertical"
                 Spacing="4">
+        <TextBlock TextAlignment="Center"
+                   FontWeight="Bold"
+                   FontSize="18"
+                   Text="Error!"/>
         <TextBlock TextAlignment="Center"
                    FontWeight="Bold"
                    TextWrapping="Wrap"
-                   FontSize="16"
+                   FontSize="14"
                    MaxWidth="350"
                    Text="{Binding Error}"/>
         <Button Command="{Binding Close}"
                 Classes="accent"
                 Content="Close"
                 HorizontalAlignment="Right"
-                Margin="0,0,4,4"/>
+                Margin="0,4,4,4"/>
     </StackPanel>
 </UserControl>