Store default date format as Screen property

Instead of setting date_format in every context (which will be included in
url), it is better to store the default value on the Screen. Also it should be
stored privately on the Screen to avoid modification which could result into an
inconsistency on the display.

issue6082
review25841002

tryton/action/main.py

@@ -69,11 +69,6 @@ class Action(object):
     def _exec_action(action, data=None, context=None):
         if context is None:
             context = {}
-        else:
-            context = context.copy()
-        if 'date_format' not in context:
-            context['date_format'] = rpc.CONTEXT.get(
-                'locale', {}).get('date', '%x')
         if data is None:
             data = {}
         else:

tryton/gui/window/view_form/screen/screen.py

@@ -137,6 +137,8 @@ class Screen(SignalEvent):
         self.search_value = search_value
         self.fields_view_tree = {}
         self.order = self.default_order = order
+        self.__date_format = context.get(
+            'date_format', rpc.CONTEXT.get('locale', {}).get('date', '%x'))
         self.view_to_load = []
         self._domain_parser = {}
         self.pre_validate = False
@@ -328,6 +330,10 @@ class Screen(SignalEvent):
     def context(self):
         return self.group.context
 
+    @property
+    def date_format(self):
+        return self.__date_format
+
     def __get_group(self):
         return self.__group
 

tryton/gui/window/view_form/view/form_gtk/calendar.py

@@ -64,7 +64,7 @@ class Date(Widget):
         if field and record:
             format_ = field.date_format(record)
         else:
-            format_ = self.view.screen.context.get('date_format', '%x')
+            format_ = self.view.screen.date_format
         self.entry.props.format = format_
 
     def display(self, record, field):
@@ -142,7 +142,7 @@ class DateTime(Date):
             date_format = field.date_format(record)
             time_format = field.time_format(record)
         else:
-            date_format = self.view.screen.context.get('date_format', '%x')
+            date_format = self.view.screen.date_format
             time_format = '%X'
         self.entry.props.date_format = date_format
         self.entry.props.time_format = time_format