ProfileDialog: Check if topo_bath field is present

PreCourlis/widgets/profile_dialog.py

@@ -375,6 +375,36 @@ class ProfileDialog(QtWidgets.QDialog, FORM_CLASS):
         if self.file is not None and self.file.layer() is not None:
             self.file.layer().layerModified.disconnect(self.layer_modified)
 
+        # Check if topo_bath field is present
+        if layer is not None:
+            if layer.fields().indexFromName("topo_bath") == -1:
+                self.message_bar.pushMessage(
+                    self.tr("Missing field"),
+                    self.tr(
+                        "The field 'topo_bath' is missing in the layer. "
+                        "Please add it before using this tool."
+                    ),
+                    Qgis.MessageLevel.Critical,
+                    duration=5,
+                )
+
+                # Show fieldcalculator algorithm dialog
+                processing.execAlgorithmDialog(
+                    "native:fieldcalculator",
+                    {
+                        'INPUT': '/app/test/data/input/profiles_lines.geojson',
+                        'FIELD_NAME': 'topo_bath',
+                        'FIELD_TYPE': 2,
+                        'FIELD_LENGTH': 0,
+                        'FIELD_PRECISION': 0,
+                        'FORMULA': "'B' || replace(rpad('', num_points($geometry) - 1, ','), ',', ',B')",
+                        'OUTPUT': 'TEMPORARY_OUTPUT'
+                    }
+                )
+
+                self.layerComboBox.setLayer(None)
+                return
+
         self.file = PreCourlisFileLine(layer)
         self.sectionItemModel.setLayer(layer)
         self.sectionComboBox.setCurrentIndex(0)