File input field is no longer required when editing

Fix for #17.
Fixes flake8 and isort issues.

tests/test_admin_views.py

@@ -9,10 +9,9 @@ from django.core.urlresolvers import reverse
 from django.template.defaultfilters import filesizeformat
 from django.test import TestCase, override_settings
 from mock import patch
+from tests.utils import create_test_video_file
 from wagtail.tests.utils import WagtailTestUtils
 from wagtail.wagtailcore.models import Collection, GroupCollectionPermission
-
-from tests.utils import create_test_video_file
 from wagtailvideos.models import Video
 
 
@@ -228,6 +227,7 @@ class TestVideoEditView(TestCase, WagtailTestUtils):
         # Check that the video was edited
         video = Video.objects.get(id=self.video.id)
         self.assertEqual(video.title, "Edited")
+        self.assertEqual(self.video.file, video.file)
 
     def test_edit_with_new_video_file(self):
         # Change the file size of the video

wagtailvideos/forms.py

@@ -7,7 +7,6 @@ from enumchoicefield.forms import EnumField
 from wagtail.wagtailadmin import widgets
 from wagtail.wagtailadmin.forms import (
     BaseCollectionMemberForm, collection_member_permission_formset_factory)
-
 from wagtailvideos.fields import WagtailVideoField
 from wagtailvideos.models import MediaFormats, Video, VideoQuality
 from wagtailvideos.permissions import \
@@ -17,6 +16,14 @@ from wagtailvideos.permissions import \
 class BaseVideoForm(BaseCollectionMemberForm):
     permission_policy = video_permission_policy
 
+    def __init__(self, *args, **kwargs):
+        super(BaseVideoForm, self).__init__(*args, **kwargs)
+        # A file is only required if there is not already a file, such as when
+        # editing an existing video.  The file field is not used on the
+        # multiple-upload forms, so may not be present
+        if 'file' in self.fields:
+            self.fields['file'].required = 'file' not in self.initial or not self.initial['file']
+
 
 # Callback to allow us to override the default form field for the image file field
 def formfield_for_dbfield(db_field, **kwargs):

wagtailvideos/models.py

@@ -11,7 +11,6 @@ import subprocess
 import tempfile
 import threading
 
-import django
 from django.conf import settings
 from django.core.files.base import ContentFile
 from django.core.urlresolvers import reverse
@@ -28,7 +27,6 @@ from wagtail.wagtailadmin.utils import get_object_usage
 from wagtail.wagtailcore.models import CollectionMember
 from wagtail.wagtailsearch import index
 from wagtail.wagtailsearch.queryset import SearchableQuerySetMixin
-
 from wagtailvideos.utils import ffmpeg_installed
 
 logger = logging.getLogger(__name__)

wagtailvideos/views/chooser.py

@@ -11,8 +11,6 @@ from wagtail.wagtailadmin.utils import (
     PermissionPolicyChecker, popular_tags_for_model)
 from wagtail.wagtailcore.models import Collection
 from wagtail.wagtailsearch import index as search_index
-from wagtail.wagtailsearch.backends import get_search_backends
-
 from wagtailvideos.forms import get_video_form
 from wagtailvideos.models import Video
 from wagtailvideos.permissions import permission_policy

wagtailvideos/views/videos.py

@@ -14,7 +14,6 @@ from wagtail.wagtailadmin.utils import (
     PermissionPolicyChecker, popular_tags_for_model)
 from wagtail.wagtailcore.models import Collection
 from wagtail.wagtailsearch.backends import get_search_backends
-
 from wagtailvideos.forms import VideoTranscodeAdminForm, get_video_form
 from wagtailvideos.models import Video
 from wagtailvideos.permissions import permission_policy
@@ -76,7 +75,6 @@ def index(request):
 @permission_checker.require('change')
 def edit(request, video_id):
     VideoForm = get_video_form(Video)
-
     video = get_object_or_404(Video, id=video_id)
 
     if request.POST: