Reusable acl error messages.

preferences/views.py

@@ -43,7 +43,7 @@ from reversion import revisions as reversion
 from importlib import import_module
 from re2o.settings_local import OPTIONNAL_APPS_RE2O
 from re2o.views import form
-from re2o.acl import can_create, can_edit, can_delete_set, can_view_all, can_delete
+from re2o.acl import can_create, can_edit, can_delete_set, can_view_all, can_delete, acl_error_message
 
 from .forms import MailContactForm, DelMailContactForm
 from .forms import (
@@ -130,10 +130,9 @@ def edit_options(request, section):
         return redirect(reverse('preferences:display-options'))
 
     options_instance, _created = model.objects.get_or_create()
-    can, msg = options_instance.can_edit(request.user)
+    can, msg, permissions = options_instance.can_edit(request.user)
     if not can:
-        messages.error(request, msg or _("You don't have the right to edit"
-                                         " this option."))
+        messages.error(request, acl_error_message(msg, permissions))
         return redirect(reverse('index'))
     options = form_instance(
         request.POST or None,

re2o/acl.py

@@ -39,12 +39,24 @@ from django.utils.translation import ugettext as _
 from re2o.utils import get_group_having_permission
 
 
-def group_list(permissions):
-    """Create a string listing every groups having one of the given
-    `permissions`."""
-    return ", ".join([
+def acl_error_message(msg, permissions):
+    """Create an error message for msg and permissions."""
+    groups = ", ".join([
         g.name for g in get_group_having_permission(*permissions)
     ])
+    message = msg or _("You don't have the right to edit"
+                                         " this option.")
+    if groups:
+        return message + _(
+                " You need to be a member of one of those"
+                " groups : %s"
+            ) % groups
+    else:
+        return message + " No group have the %s permission(s) !" % " or ".join([
+            ",".join(permissions[:-1]),
+            permissions[-1]]
+            if len(permissions) > 2 else permissions
+        )
 
 
 def acl_base_decorator(method_name, *targets, on_instance=True):
@@ -163,23 +175,8 @@ ModelC)
             for target, fields in group_targets():
                 for can, msg, permissions in process_target(target, fields):
                     if not can:
-                        groups = group_list(permissions)
-                        if groups:
-                            error_messages.append(
-                                msg + _(
-                                    " You need to be a member of one of those"
-                                    " groups : %s"
-                                ) % groups
-                            )
-                        else:
-                            error_messages.append(
-                                msg + " No group have the %s permission(s) !" \
-                                % " or ".join([
-                                    ",".join(permissions[:-1]),
-                                    permissions[-1]]
-                                    if len(permissions) > 2 else permissions
-                                )
-                            )
+                        error_messages.append(acl_error_message(msg, permissions))
+
             if error_messages:
                 for msg in error_messages:
                     messages.error(

re2o/field_permissions.py

@@ -69,7 +69,7 @@ class FieldPermissionModelMixin:
         # Try to find a user setting that qualifies them for permission.
         for perm in checks:
             if callable(perm):
-                result, _reason = perm(user_request=user)
+                result, _reason, _permissions = perm(user_request=user)
                 if result is not None:
                     return result
             else: