Merge remote-tracking branch 'origin/pr/319'

AUTHORS

@@ -25,7 +25,7 @@ that much better:
  * flosch
  * Deepak Thukral
  * Colin Howe
- * Wilson Júnior
+ * Wilson Júnior (https://github.com/wpjunior)
  * Alistair Roche
  * Dan Crosta
  * Viktor Kerkez

mongoengine/fields.py

@@ -1442,6 +1442,17 @@ class SequenceField(BaseField):
                                              upsert=True)
         return self.value_decorator(counter['next'])
 
+    def get_next_value(self):
+        sequence_name = self.get_sequence_name()
+        sequence_id = "%s.%s" % (sequence_name, self.name)
+        collection = get_db(alias=self.db_alias)[self.collection_name]
+        data = collection.find_one({"_id": sequence_id})
+
+        if data:
+            return self.value_decorator(data['next']+1)
+
+        return self.value_decorator(1)
+
     def get_sequence_name(self):
         if self.sequence_name:
             return self.sequence_name

tests/fields/fields.py

@@ -1898,6 +1898,38 @@ class FieldTest(unittest.TestCase):
         c = self.db['mongoengine.counters'].find_one({'_id': 'person.id'})
         self.assertEqual(c['next'], 1000)
 
+
+    def test_sequence_field_get_next_value(self):
+        class Person(Document):
+            id = SequenceField(primary_key=True)
+            name = StringField()
+
+        self.db['mongoengine.counters'].drop()
+        Person.drop_collection()
+
+        for x in xrange(10):
+            Person(name="Person %s" % x).save()
+
+        self.assertEqual(Person.id.get_next_value(), 11)
+        self.db['mongoengine.counters'].drop()
+
+        self.assertEqual(Person.id.get_next_value(), 1)
+
+        class Person(Document):
+            id = SequenceField(primary_key=True, value_decorator=str)
+            name = StringField()
+
+        self.db['mongoengine.counters'].drop()
+        Person.drop_collection()
+
+        for x in xrange(10):
+            Person(name="Person %s" % x).save()
+
+        self.assertEqual(Person.id.get_next_value(), '11')
+        self.db['mongoengine.counters'].drop()
+
+        self.assertEqual(Person.id.get_next_value(), '1')
+        
     def test_sequence_field_sequence_name(self):
         class Person(Document):
             id = SequenceField(primary_key=True, sequence_name='jelly')