Fixes #164

There appears to be quite the mess out there with regard to how DRF
handles filtering.  DRF has its own built-in stuff, but recommends
django_filter for the advanced stuff, which has its own overriding
module that explodes with this message when used as per the
documentation:

  AttributeError: 'NoneType' object has no attribute 'DjangoFilterBackend'

Then there's djangorestframework-filter, another package that claims to
do the same thing, that does everything just differently enough that
nothing worked while I had it enabled.

I ended up using django_filter, but doing so importing each element
explicitly, rather than just using the recommended (and broken, at least
in this project) method of:

    import django_filter.restframework as fitlers

Anyway, this should bring the dependencies up to date, and strips out a
lot of redundant code.

requirements.txt

@@ -1,10 +1,9 @@
-Django==1.10.3
+Django==1.10.4
 Pillow>=3.1.1
 django-crispy-forms>=1.6.0
 django-extensions>=1.6.1
-django-filter>=0.12.0,<1.0
+django-filter>=1.0
 djangorestframework>=3.4.4
-djangorestframework-filters>=0.8.0
 filemagic>=1.6
 langdetect>=1.0.5
 pyocr>=0.3.1

src/documents/filters.py

@@ -1,152 +1,58 @@
-import django_filters
+from django_filters.rest_framework import CharFilter, FilterSet
 
-from rest_framework import filters
-
-from .models import Document, Correspondent, Tag
-
-#
-# I hate how copy/pastey this file is.  Recommendations are welcome.
-#
+from .models import Correspondent, Document, Tag
 
 
-# Filters
-
-
-class RelatedFilter(django_filters.MethodFilter):
-
-    def __init__(self, *args, **kwargs):
-        self.key = kwargs.pop("key")
-        self.lookup_type = kwargs.get("lookup_type")
-        django_filters.MethodFilter.__init__(self, *args, **kwargs)
-
-    def filter(self, qs, value):
-        if not value:
-            return qs
-        return qs.filter(**{"tags__{}".format(self.key): value})
-
-
-# FilterSets
-
-
-class SluggableFilterSet(filters.FilterSet):
-
-    name__startswith = django_filters.CharFilter(
-        name="name", lookup_type="startswith",
-        label="Name starts with (case sensitive)"
-    )
-    name__istartswith = django_filters.CharFilter(
-        name="name", lookup_type="istartswith",
-        label="Name starts with (case insensitive)"
-    )
-    name__endswith = django_filters.CharFilter(
-        name="name", lookup_type="endswith",
-        label="Name ends with (case sensitive)"
-    )
-    name__iendswith = django_filters.CharFilter(
-        name="name", lookup_type="endswith",
-        label="Name ends with (case insensitive)"
-    )
-    name__contains = django_filters.CharFilter(
-        name="name", lookup_type="contains",
-        label="Name contains (case sensitive)"
-    )
-    name__icontains = django_filters.CharFilter(
-        name="name", lookup_type="icontains",
-        label="Name contains (case insensitive)"
-    )
-
-    slug__istartswith = django_filters.CharFilter(
-        name="slug", lookup_type="istartswith",
-        label="Slug starts with (case insensitive)"
-    )
-    slug__iendswith = django_filters.CharFilter(
-        name="slug", lookup_type="endswith",
-        label="Slug ends with (case insensitive)"
-    )
-    slug__icontains = django_filters.CharFilter(
-        name="slug", lookup_type="icontains",
-        label="Slug contains (case insensitive)"
-    )
-
-
-class CorrespondentFilterSet(SluggableFilterSet):
+class CorrespondentFilterSet(FilterSet):
 
     class Meta(object):
         model = Correspondent
-        fields = ["name"]
+        fields = {
+            'name': [
+                "startswith", "endswith", "contains",
+                "istartswith", "iendswith", "icontains"
+            ],
+            "slug": ["istartswith", "iendswith", "icontains"]
+        }
 
 
-class TagFilterSet(SluggableFilterSet):
+class TagFilterSet(FilterSet):
 
     class Meta(object):
         model = Tag
-        fields = ["name", "slug"]
+        fields = {
+            'name': [
+                "startswith", "endswith", "contains",
+                "istartswith", "iendswith", "icontains"
+            ],
+            "slug": ["istartswith", "iendswith", "icontains"]
+        }
 
 
-class DocumentFilterSet(filters.FilterSet):
+class DocumentFilterSet(FilterSet):
 
-    title__startswith = django_filters.CharFilter(
-        name="title", lookup_type="startswith",
-        label="Title starts with (case sensitive)"
-    )
-    title__istartswith = django_filters.CharFilter(
-        name="title", lookup_type="istartswith",
-        label="Title starts with (case insensitive)"
-    )
-    title__endswith = django_filters.CharFilter(
-        name="title", lookup_type="endswith",
-        label="Title ends with (case sensitive)"
-    )
-    title__iendswith = django_filters.CharFilter(
-        name="title", lookup_type="endswith",
-        label="Title ends with (case insensitive)"
-    )
-    title__contains = django_filters.CharFilter(
-        name="title", lookup_type="contains",
-        label="Title contains (case sensitive)"
-    )
-    title__icontains = django_filters.CharFilter(
-        name="title", lookup_type="icontains",
-        label="Title contains (case insensitive)"
-    )
+    CHAR_KWARGS = {
+        "lookup_expr": (
+            "startswith",
+            "endswith",
+            "contains",
+            "istartswith",
+            "iendswith",
+            "icontains"
+        )
+    }
 
-    content__contains = django_filters.CharFilter(
-        name="content", lookup_type="contains")
-    content__icontains = django_filters.CharFilter(
-        name="content", lookup_type="icontains")
-
-    tags__name = RelatedFilter(key="name")
-    tags__name__startswith = RelatedFilter(key="name__startswith")
-    tags__name__istartswith = RelatedFilter(key="name__istartswith")
-    tags__name__endswith = RelatedFilter(key="name__endswith")
-    tags__name__iendswith = RelatedFilter(key="name__iendswith")
-    tags__name__contains = RelatedFilter(key="name__contains")
-    tags__name__icontains = RelatedFilter(key="name__icontains")
-
-    tags__slug = RelatedFilter(key="slug")
-    tags__slug__startswith = RelatedFilter(key="slug__startswith")
-    tags__slug__istartswith = RelatedFilter(key="slug__istartswith")
-    tags__slug__endswith = RelatedFilter(key="slug__endswith")
-    tags__slug__iendswith = RelatedFilter(key="slug__iendswith")
-    tags__slug__contains = RelatedFilter(key="slug__contains")
-    tags__slug__icontains = RelatedFilter(key="slug__icontains")
-
-    correspondent__name = RelatedFilter(key="name")
-    correspondent__name__startswith = RelatedFilter(key="name__startswith")
-    correspondent__name__istartswith = RelatedFilter(key="name__istartswith")
-    correspondent__name__endswith = RelatedFilter(key="name__endswith")
-    correspondent__name__iendswith = RelatedFilter(key="name__iendswith")
-    correspondent__name__contains = RelatedFilter(key="name__contains")
-    correspondent__name__icontains = RelatedFilter(key="name__icontains")
-
-    correspondent__slug = RelatedFilter(key="slug")
-    correspondent__slug__startswith = RelatedFilter(key="slug__startswith")
-    correspondent__slug__istartswith = RelatedFilter(key="slug__istartswith")
-    correspondent__slug__endswith = RelatedFilter(key="slug__endswith")
-    correspondent__slug__iendswith = RelatedFilter(key="slug__iendswith")
-    correspondent__slug__contains = RelatedFilter(key="slug__contains")
-    correspondent__slug__icontains = RelatedFilter(key="slug__icontains")
+    correspondent__name = CharFilter(name="correspondent__name", **CHAR_KWARGS)
+    correspondent__slug = CharFilter(name="correspondent__slug", **CHAR_KWARGS)
+    tags__name = CharFilter(name="tags__name", **CHAR_KWARGS)
+    tags__slug = CharFilter(name="tags__slug", **CHAR_KWARGS)
 
     class Meta(object):
         model = Document
-        fields = ["title"]
+        fields = {
+            "title": [
+                "startswith", "endswith", "contains",
+                "istartswith", "iendswith", "icontains"
+            ],
+            "content": ["contains", "icontains"],
+        }

src/documents/views.py

@@ -1,23 +1,33 @@
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.http import HttpResponse
 from django.views.decorators.csrf import csrf_exempt
-from django.views.generic import FormView, DetailView, TemplateView
-
-from rest_framework import filters
+from django.views.generic import DetailView, FormView, TemplateView
+from django_filters.rest_framework import DjangoFilterBackend
+from rest_framework.filters import SearchFilter, OrderingFilter
+from paperless.db import GnuPG
 from rest_framework.mixins import (
-    RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, ListModelMixin)
+    DestroyModelMixin,
+    ListModelMixin,
+    RetrieveModelMixin,
+    UpdateModelMixin
+)
 from rest_framework.pagination import PageNumberPagination
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.viewsets import (
-    ModelViewSet, ReadOnlyModelViewSet, GenericViewSet)
+    GenericViewSet,
+    ModelViewSet,
+    ReadOnlyModelViewSet
+)
 
-from paperless.db import GnuPG
-
-from .filters import DocumentFilterSet, CorrespondentFilterSet, TagFilterSet
+from .filters import CorrespondentFilterSet, DocumentFilterSet, TagFilterSet
 from .forms import UploadForm
-from .models import Correspondent, Tag, Document, Log
+from .models import Correspondent, Document, Log, Tag
 from .serialisers import (
-    CorrespondentSerializer, TagSerializer, DocumentSerializer, LogSerializer)
+    CorrespondentSerializer,
+    DocumentSerializer,
+    LogSerializer,
+    TagSerializer
+)
 
 
 class IndexView(TemplateView):
@@ -94,7 +104,7 @@ class CorrespondentViewSet(ModelViewSet):
     serializer_class = CorrespondentSerializer
     pagination_class = StandardPagination
     permission_classes = (IsAuthenticated,)
-    filter_backends = (filters.DjangoFilterBackend, filters.OrderingFilter)
+    filter_backends = (DjangoFilterBackend, OrderingFilter)
     filter_class = CorrespondentFilterSet
     ordering_fields = ("name", "slug")
 
@@ -105,7 +115,7 @@ class TagViewSet(ModelViewSet):
     serializer_class = TagSerializer
     pagination_class = StandardPagination
     permission_classes = (IsAuthenticated,)
-    filter_backends = (filters.DjangoFilterBackend, filters.OrderingFilter)
+    filter_backends = (DjangoFilterBackend, OrderingFilter)
     filter_class = TagFilterSet
     ordering_fields = ("name", "slug")
 
@@ -120,11 +130,7 @@ class DocumentViewSet(RetrieveModelMixin,
     serializer_class = DocumentSerializer
     pagination_class = StandardPagination
     permission_classes = (IsAuthenticated,)
-    filter_backends = (
-        filters.DjangoFilterBackend,
-        filters.SearchFilter,
-        filters.OrderingFilter
-    )
+    filter_backends = (DjangoFilterBackend, SearchFilter, OrderingFilter)
     filter_class = DocumentFilterSet
     search_fields = ("title", "correspondent__name", "content")
     ordering_fields = (
@@ -137,5 +143,5 @@ class LogViewSet(ReadOnlyModelViewSet):
     serializer_class = LogSerializer
     pagination_class = StandardPagination
     permission_classes = (IsAuthenticated,)
-    filter_backends = (filters.DjangoFilterBackend, filters.OrderingFilter)
+    filter_backends = (DjangoFilterBackend, OrderingFilter)
     ordering_fields = ("time",)

src/paperless/settings.py

@@ -36,7 +36,6 @@ if os.path.exists("/etc/paperless.conf"):
     load_dotenv("/etc/paperless.conf")
 
 
-
 # Application definition
 
 INSTALLED_APPS = [