Fix bug related to error when user delete or rename the predefined fo…

…lder containing all FIT_MODELs

app/common.py

@@ -1611,6 +1611,33 @@ def __init__(self, graph_id=None):
         # Set layout margins to 0 to remove extra space
         self.graph_layout.setContentsMargins(0, 0, 0, 0)
         self.graph_layout.setSpacing(0)
+
+    def save(self, fname=None):
+        """ Save Graph object to serialization. Save it if a fname is given """
+        # List of keys to exclude from serialization
+        excluded_keys = ['figure', 'canvas', 'setLayout', 'graph_layout',
+                         'some_signal_instance']
+
+        dict_graph = {}
+        for key, val in vars(self).items():
+            if key not in excluded_keys and not callable(val):
+                try:
+                    json.dumps(val)
+                    dict_graph[key] = val
+                except TypeError:
+                    continue
+
+        if fname is not None:
+            with open(fname, 'w') as f:
+                json.dump(dict_graph, f, indent=4)
+
+        return dict_graph
+
+    def set_attributes(self, attributes_dict):
+        """Set attributes of the Graph object from a given dictionary."""
+        for key, value in attributes_dict.items():
+            if hasattr(self, key):
+                setattr(self, key, value)
 
     def clear_layout(self, layout):
         """Clears all widgets and layouts from the specified layout."""
@@ -2026,33 +2053,7 @@ def _plot_tertiary_axis(self, df):
             self.ax3.set_ylabel(self.y3label, color='green')
             self.ax3.tick_params(axis='y', colors='green')
 
-    def save(self, fname=None):
-        """ Save Graph object to serialization. Save it if a fname is given """
-        # List of keys to exclude from serialization
-        excluded_keys = ['figure', 'canvas', 'setLayout', 'graph_layout',
-                         'some_signal_instance']
-
-        dict_graph = {}
-        for key, val in vars(self).items():
-            if key not in excluded_keys and not callable(val):
-                try:
-                    json.dumps(val)
-                    dict_graph[key] = val
-                except TypeError:
-                    continue
-
-        if fname is not None:
-            with open(fname, 'w') as f:
-                json.dump(dict_graph, f, indent=4)
-
-        return dict_graph
-
-    def set_attributes(self, attributes_dict):
-        """Set attributes of the Graph object from a given dictionary."""
-        for key, value in attributes_dict.items():
-            if hasattr(self, key):
-                setattr(self, key, value)
-
+
 
 class FitModelManager:
     """
@@ -2067,8 +2068,7 @@ class FitModelManager:
 
     def __init__(self, settings):
         self.settings = settings
-        self.default_model_folder = self.settings.value("default_model_folder",
-                                                        "")
+        self.default_model_folder = self.settings.value("default_model_folder","")
         self.available_models = []
         if self.default_model_folder:
             self.scan_models()
@@ -2089,14 +2089,28 @@ def scan_models(self):
         Scan the default folder and populate the available_models list.
 
         This method scans the default_model_folder for files with the '.json'
-        extension
-        and updates the available_models list accordingly.
+        extension and updates the available_models list accordingly.
         """
         self.available_models = []
+
         if self.default_model_folder:
-            for file_name in os.listdir(self.default_model_folder):
-                if file_name.endswith('.json'):
-                    self.available_models.append(file_name)
+            if not os.path.exists(self.default_model_folder):
+                # Folder is specified but does not exist
+                msg= f"Default 'Fit_models' folder '{self.default_model_folder}' not found. Please specify another one."
+                show_alert(msg)
+                # Reset the default model folder to empty
+                self.default_model_folder = ""
+                self.settings.setValue("default_model_folder", "")
+                return  # Exit the method since the folder is missing
+
+            # Scan the folder for JSON files if it exists
+            try:
+                for file_name in os.listdir(self.default_model_folder):
+                    if file_name.endswith('.json'):
+                        self.available_models.append(file_name)
+            except Exception as e:
+                print(f"Error scanning the folder '{self.default_model_folder}': {e}")
+
 
     def get_available_models(self):
         """

app/visualisation.py

@@ -828,11 +828,12 @@ def load(self, file_path):
                     sub_window.show()
 
                     self.plot_action()
+
                 self.filter.upd_filter_listbox()
                 self.add_graph_list_to_combobox()
 
         except Exception as e:
-            show_alert(f"Error loading work: {e}")
+            print(f"Error loading work: {e}")
 
     def delete_graph(self, graph_id):
         """Delete the specified graph from the plots dictionary by graph_id"""