diff -r d9ee6f8ddb76 -r 31687784fa16 src/pyams_gis/zmi/widget/area.py
--- a/src/pyams_gis/zmi/widget/area.py	Wed Jan 27 15:37:20 2021 +0100
+++ b/src/pyams_gis/zmi/widget/area.py	Wed Jan 27 15:38:26 2021 +0100
@@ -32,21 +32,15 @@
 
 
 @adapter_config(name=getIfName(IGeoArea),
-                context=(Interface, IFormLayer, IForm, IGeoAreaWidget), provides=IObjectFactory)
-class GeoAreaObjectFactory(object):
+                context=(Interface, IFormLayer, IForm, IGeoAreaWidget),
+                provides=IObjectFactory)
+def geo_area_object_factory(*args, **kwargs):
     """GeoArea object factory"""
-
-    def __init__(self, context, request, form, widget):
-        self.context = context
-        self.request = request
-        self.form = form
-        self.widget = widget
-
-    def __call__(self, data):
-        return GeoArea()
+    return GeoArea
 
 
-@widgettemplate_config(mode='input', template='templates/geoarea-input.pt', layer=IFormLayer)
+@widgettemplate_config(mode='input',
+                       template='templates/geoarea-input.pt', layer=IFormLayer)
 @implementer_only(IGeoAreaWidget)
 class GeoAreaWidget(ObjectWidget):
     """GeoArea widget"""
@@ -56,19 +50,27 @@
         widgets = self.widgets
         x1 = widgets['x1']
         x1.input_css_class = 'col-md-2'
-        x1.object_data = {'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'}
+        x1.object_data = {
+            'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'
+        }
         alsoProvides(x1, IObjectData)
         x2 = widgets['x2']
         x2.input_css_class = 'col-md-2'
-        x2.object_data = {'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'}
+        x2.object_data = {
+            'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'
+        }
         alsoProvides(x2, IObjectData)
         y1 = widgets['y1']
         y1.input_css_class = 'col-md-2'
-        y1.object_data = {'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'}
+        y1.object_data = {
+            'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'
+        }
         alsoProvides(y1, IObjectData)
         y2 = widgets['y2']
         y2.input_css_class = 'col-md-2'
-        y2.object_data = {'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'}
+        y2.object_data = {
+            'ams-change-handler': 'PyAMS_GIS.area.changedCoordinate'
+        }
         alsoProvides(y2, IObjectData)
         projection = widgets['projection']
         projection.object_data = {
@@ -82,19 +84,24 @@
     def wgs_coordinates(self):
         value = self.field.get(self.field.interface(self.context))
         if not value:
-            return json.dumps({'x1': None,
-                               'y1': None,
-                               'x2': None,
-                               'y2': None})
+            return json.dumps({
+                'x1': None,
+                'y1': None,
+                'x2': None,
+                'y2': None
+            })
         else:
             point1, point2 = value.wgs_coordinates
-            return json.dumps({'x1': float(point1[0]),
-                               'y1': float(point1[1]),
-                               'x2': float(point2[0]),
-                               'y2': float(point2[1])})
+            return json.dumps({
+                'x1': float(point1[0]),
+                'y1': float(point1[1]),
+                'x2': float(point2[0]),
+                'y2': float(point2[1])
+            })
 
 
-@adapter_config(context=(IGeoAreaField, IFormLayer), provides=IFieldWidget)
+@adapter_config(context=(IGeoAreaField, IFormLayer),
+                provides=IFieldWidget)
 def GeoAreaFieldWidget(field, request):
     """GeoArea field widget factory"""
     return FieldWidget(field, GeoAreaWidget(request))