Support Django 2.0

.travis.yml

@@ -16,6 +16,7 @@ env:
   - DJANGO_VERSION='Django>=1.9,<1.10'
   - DJANGO_VERSION='Django>=1.10,<1.11'
   - DJANGO_VERSION='Django>=1.11,<2.0'
+  - DJANGO_VERSION='Django>=2.0,<2.1'
   - DJANGO_VERSION='https://github.com/django/django/archive/master.tar.gz'
 matrix:
   exclude:
@@ -29,8 +30,12 @@ matrix:
       env: DJANGO_VERSION='Django>=1.10,<1.11'
     - python: "2.6"
       env: DJANGO_VERSION='Django>=1.11,<2.0'
+    - python: "2.6"
+      env: DJANGO_VERSION='Django>=2.0,<2.1'
     - python: "2.6"
       env: DJANGO_VERSION='https://github.com/django/django/archive/master.tar.gz'
+    - python: "2.7"
+      env: DJANGO_VERSION='Django>=2.0,<2.1'
     - python: "2.7"
       env: DJANGO_VERSION='https://github.com/django/django/archive/master.tar.gz'
     - python: "3.3"
@@ -43,6 +48,8 @@ matrix:
       env: DJANGO_VERSION='Django>=1.10,<1.11'
     - python: "3.3"
       env: DJANGO_VERSION='Django>=1.11,<2.0'
+    - python: "3.3"
+      env: DJANGO_VERSION='Django>=2.0,<2.1'
     - python: "3.3"
       env: DJANGO_VERSION='https://github.com/django/django/archive/master.tar.gz'
     - python: "3.4"

example/app/models.py

@@ -15,7 +15,7 @@
 # along with this software.  If not, see <http://www.gnu.org/licenses/>.
 
 from django.db import models
-from django.utils.translation import gettext as _
+from django.utils.translation import gettext_lazy as _
 
 from multiselectfield import MultiSelectField
 

multiselectfield/db/fields.py

@@ -55,8 +55,8 @@ def __init__(self, choices, *args, **kwargs):
         super(MSFList, self).__init__(*args, **kwargs)
 
     def __str__(msgl):
-        l = [msgl.choices.get(int(i)) if i.isdigit() else msgl.choices.get(i) for i in msgl]
-        return u', '.join([string_type(s) for s in l])
+        lst = [msgl.choices.get(int(i)) if i.isdigit() else msgl.choices.get(i) for i in msgl]
+        return u', '.join([string_type(s) for s in lst])
 
 
 class MultiSelectField(models.CharField):
@@ -74,7 +74,7 @@ def __init__(self, *args, **kwargs):
             self.validators.append(MaxChoicesValidator(self.max_choices))
 
     def _get_flatchoices(self):
-        l = super(MultiSelectField, self)._get_flatchoices()
+        lst = super(MultiSelectField, self)._get_flatchoices()
 
         class MSFFlatchoices(list):
             # Used to trick django.contrib.admin.utils.display_for_field into
@@ -83,7 +83,7 @@ class MSFFlatchoices(list):
             def __bool__(self):
                 return False
             __nonzero__ = __bool__
-        return MSFFlatchoices(l)
+        return MSFFlatchoices(lst)
     flatchoices = property(_get_flatchoices)
 
     def get_choices_default(self):
@@ -102,7 +102,10 @@ def get_choices_selected(self, arr_choices):
         return choices_selected
 
     def value_to_string(self, obj):
-        value = self._get_val_from_obj(obj)
+        try:
+            value = self.val_from_object(obj)
+        except AttributeError:
+            value = self._get_val_from_obj(obj)
         return self.get_prep_value(value)
 
     def validate(self, value, model_instance):