set offline layers in value relation widgets

qfieldsync/core/offline_converter.py

@@ -43,7 +43,9 @@
     QgsBilinearRasterResampler,
     QgsApplication,
     QgsProcessingFeedback,
-    QgsProcessingContext
+    QgsProcessingContext,
+    QgsMapLayer,
+    QgsEditorWidgetSetup
 )
 import qgis
 
@@ -78,6 +80,7 @@ def convert(self):
         """
 
         project = QgsProject.instance()
+        original_project = project
 
         original_project_path = project.fileName()
         project_filename, _ = os.path.splitext(os.path.basename(original_project_path))
@@ -96,6 +99,10 @@ def convert(self):
             self.__offline_layers = list()
             self.__layers = list(project.mapLayers().values())
 
+            original_names = {}
+            for layer in self.__layers:
+                original_names[layer.id()] = layer.name()
+
             self.total_progress_updated.emit(0, 1, self.tr('Creating base map'))
             # Create the base map before layers are removed
             if self.project_configuration.create_base_map:
@@ -150,6 +157,7 @@ def convert(self):
                                                                         offline_layer_ids,
                                                                         self.project_configuration.offline_copy_only_aoi, self.offline_editing.GPKG):
                         raise Exception(self.tr("Error trying to convert layers to offline layers"))
+
             except AttributeError:
                 # Run the offline plugin for spatialite
                 spatialite_filename = "data.sqlite"
@@ -166,6 +174,18 @@ def convert(self):
                 QgsProject.instance().setEvaluateDefaultValues(False)
                 QgsProject.instance().setAutoTransaction(False)
 
+                # check and convert value relations
+                for layer in project.mapLayers().values():
+                    if layer.type() == QgsMapLayer.VectorLayer:
+                        for field in layer.fields():
+                            ews = field.editorWidgetSetup()
+                            if ews.type() == 'ValueRelation':
+                                online_layer_id = ews.config()['Layer']
+                                layer_name = original_names[online_layer_id] + " (offline)"
+                                layer_id = project.mapLayersByName(layer_name)[0].id()
+                                ews.config()['Layer'] = layer_id
+                                layer.setEditorWidgetSetup(layer.fields().indexOf(field.name()), ews)
+
             # Now we have a project state which can be saved as offline project
             QgsProject.instance().write(project_path)
         finally: