Merge pull request #360 from ericbuckley/dynamic_default_field

fix for fields with a dyanmic default callable

import_export/fields.py

@@ -67,8 +67,7 @@ def clean(self, data):
 
         if not value and self.default != NOT_PROVIDED:
             if callable(self.default):
-                self.default = self.default()
-            return self.default
+                return self.default()
 
         return value
 

tests/core/models.py

@@ -1,4 +1,6 @@
 from __future__ import unicode_literals
+import random
+import string
 
 from django.db import models
 from django.utils.encoding import python_2_unicode_compatible
@@ -48,3 +50,12 @@ class Entry(models.Model):
 class WithDefault(models.Model):
     name = models.CharField('Default', max_length=75, blank=True,
                             default=lambda: 'foo_bar')
+
+
+class WithDynamicDefault(models.Model):
+    def random_name():
+        chars = string.ascii_lowercase
+        return ''.join(random.SystemRandom().choice(chars) for _ in range(100))
+
+    name = models.CharField('Dyn Default', max_length=100,
+            default=random_name)

tests/core/tests/resources_tests.py

@@ -26,7 +26,7 @@
 from import_export import results
 from import_export.instance_loaders import ModelInstanceLoader
 
-from core.models import Book, Author, Category, Entry, Profile, WithDefault
+from core.models import Book, Author, Category, Entry, Profile, WithDefault, WithDynamicDefault
 
 try:
     from django.utils.encoding import force_text
@@ -587,6 +587,20 @@ def after_save_instance(self, instance, dry_run):
         self.assertFalse(result.has_errors())
         self.assertEquals(User.objects.get(pk=user.pk).username, 'bar')
 
+    def test_import_data_dynamic_default_callable(self):
+        class DynamicDefaultResource(resources.ModelResource):
+            class Meta:
+                model = WithDynamicDefault
+                fields = ('id', 'name',)
+
+        resource = DynamicDefaultResource()
+        dataset = tablib.Dataset(headers=['id', 'name',])
+        dataset.append([1, None])
+        dataset.append([2, None])
+        resource.import_data(dataset, raise_errors=False)
+        objs = WithDynamicDefault.objects.all()
+        self.assertNotEqual(objs[0].name, objs[1].name)
+
 
 class ModelResourceTransactionTest(TransactionTestCase):