Convert the signature download view to CBV and add corresponding test.

mayan/apps/document_signatures/views.py

@@ -2,25 +2,20 @@ from __future__ import absolute_import, unicode_literals
 
 import logging
 
-from django.conf import settings
-from django.contrib import messages
 from django.core.exceptions import PermissionDenied
 from django.core.urlresolvers import reverse
-from django.http import HttpResponseRedirect
-from django.shortcuts import get_object_or_404, render_to_response
-from django.template import RequestContext
+from django.shortcuts import get_object_or_404
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList
 from common.generics import (
     SingleObjectCreateView, SingleObjectDeleteView, SingleObjectDetailView,
-    SingleObjectListView
+    SingleObjectDownloadView, SingleObjectListView
 )
 from documents.models import DocumentVersion
-from filetransfers.api import serve_file
 from permissions import Permission
 
-from .forms import DetachedSignatureForm, DocumentVersionSignatureDetailForm
+from .forms import DocumentVersionSignatureDetailForm
 from .models import DetachedSignature, SignatureBaseModel
 from .permissions import (
     permission_document_version_signature_view,
@@ -34,12 +29,16 @@ logger = logging.getLogger(__name__)
 
 class DocumentVersionSignatureDeleteView(SingleObjectDeleteView):
     model = DetachedSignature
+    object_permission = permission_document_version_signature_delete
+    object_permission_related = 'document_version.document'
 
     def get_extra_context(self):
         return {
             'document': self.get_object().document_version.document,
             'document_version': self.get_object().document_version,
-            'navigation_object_list': ('document', 'document_version', 'signature'),
+            'navigation_object_list': (
+                'document', 'document_version', 'signature'
+            ),
             'signature': self.get_object(),
             'title': _('Delete detached signature: %s') % self.get_object()
         }
@@ -61,7 +60,9 @@ class DocumentVersionSignatureDetailView(SingleObjectDetailView):
             'document': self.get_object().document_version.document,
             'document_version': self.get_object().document_version,
             'signature': self.get_object(),
-            'navigation_object_list': ('document', 'document_version', 'signature'),
+            'navigation_object_list': (
+                'document', 'document_version', 'signature'
+            ),
             'hide_object': True,
             'title': _(
                 'Details for signature: %s'
@@ -72,6 +73,19 @@ class DocumentVersionSignatureDetailView(SingleObjectDetailView):
         return SignatureBaseModel.objects.select_subclasses()
 
 
+class DocumentSignatureDownloadView(SingleObjectDownloadView):
+    model = DetachedSignature
+    object_permission = permission_document_version_signature_download
+    object_permission_related = 'document_version.document'
+
+    def get_file(self):
+        signature = self.get_object()
+
+        return DocumentSignatureDownloadView.VirtualFile(
+            signature.signature_file, name=unicode(signature)
+        )
+
+
 class DocumentVersionSignatureListView(SingleObjectListView):
     object_permission = permission_document_version_signature_view
     object_permission_related = 'document_version.document'
@@ -95,11 +109,14 @@ class DocumentVersionSignatureListView(SingleObjectListView):
 
         try:
             Permission.check_permissions(
-                self.request.user, (permission_document_version_signature_view,)
+                self.request.user, (
+                    permission_document_version_signature_view,
+                )
             )
         except PermissionDenied:
             return AccessControlList.objects.filter_by_access(
-                permission_document_version_signature_view, self.request.user, queryset
+                permission_document_version_signature_view, self.request.user,
+                queryset
             )
         else:
             return queryset
@@ -145,24 +162,3 @@ class DocumentVersionSignatureUploadView(SingleObjectCreateView):
             'signatures:document_version_signature_list',
             args=(self.get_document_version().pk,)
         )
-
-
-def document_signature_download(request, pk):
-    signature = get_object_or_404(DetachedSignature, pk=pk)
-
-    try:
-        Permission.check_permissions(
-            request.user, (permission_document_version_signature_download,)
-        )
-    except PermissionDenied:
-        AccessControlList.objects.check_access(
-            permission_document_version_signature_download, request.user,
-            signature.document_version.signature
-        )
-
-    return serve_file(
-        request,
-        signature,
-        save_as='"%s.sig"' % signature.document_version.document,
-        content_type='application/octet-stream'
-    )