refactor: dedicated loadPaneToDialog function replacing the previous workaround

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/AppLoader.java

@@ -12,6 +12,7 @@ import ch.zhaw.gartenverwaltung.models.GardenSchedule;
 import ch.zhaw.gartenverwaltung.models.PlantListModel;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
+import javafx.scene.control.DialogPane;
 import javafx.scene.layout.Pane;
 import javafx.stage.Stage;
 
@@ -78,6 +79,24 @@ public class AppLoader {
         return controller;
     }
 
+    /**
+     * Loads the given fxml-file from resources (no caching) and appendeds it's
+     * contents to the given {@link DialogPane}.
+     * Performs dependency-injection.
+     *
+     * @param fxmlFile The file name to be loaded
+     * @param appendee The {@link DialogPane} to which the FXML contents are to be appended.
+     * @return The controller of the loaded scene.
+     * @throws IOException if the file could not be loaded
+     */
+    public Object loadPaneToDialog(String fxmlFile, DialogPane appendee) throws IOException {
+        FXMLLoader loader = new FXMLLoader(Objects.requireNonNull(HelloApplication.class.getResource(fxmlFile)));
+        appendee.setContent(loader.load());
+        Object controller = loader.getController();
+        annotationInject(controller);
+        return controller;
+    }
+
     /**
      * Loads the given fxml-file from resources and caches the pane.
      * Performs dependency-injection.