Add support for preserving the file extenstion when downloading a document

version. GitLab issue #415.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/documents/models.py

@@ -396,9 +396,7 @@ class DocumentVersion(models.Model):
         verbose_name_plural = _('Document version')
 
     def __str__(self):
-        return Template(
-            '{{ instance.document }} - {{ instance.timestamp }}'
-        ).render(context=Context({'instance': self}))
+        return self.get_rendered_string()
 
     def delete(self, *args, **kwargs):
         for page in self.pages.all():
@@ -411,6 +409,16 @@ class DocumentVersion(models.Model):
     def get_absolute_url(self):
         return reverse('documents:document_version_view', args=(self.pk,))
 
+    def get_rendered_string(self):
+        return Template(
+            '{{ instance.document }} - {{ instance.timestamp }}'
+        ).render(context=Context({'instance': self}))
+
+    def get_rendered_timestamp(self):
+        return Template('{{ instance.timestamp }}').render(
+            context=Context({'instance': self})
+        )
+
     def save(self, *args, **kwargs):
         """
         Overloaded save method that updates the document version's checksum,