Added support for filtering on related model fields. Thanks to Yuri Baburov

Author: alex

django_filters/filterset.py

@@ -2,6 +2,9 @@
 
 from django import forms
 from django.db import models
+from django.db.models.fields import FieldDoesNotExist
+from django.db.models.related import RelatedObject
+from django.db.models.sql.constants import LOOKUP_SEP
 from django.utils.datastructures import SortedDict
 from django.utils.text import capfirst
 
@@ -32,21 +35,43 @@ def get_declared_filters(bases, attrs, with_base_filters=True):
 
     return SortedDict(filters)
 
+def get_model_field(model, f):
+    parts = f.split(LOOKUP_SEP)
+    opts = model._meta
+    for name in parts[:-1]:
+        try:
+            rel = opts.get_field_by_name(name)[0]
+        except FieldDoesNotExist:
+            return None
+        if isinstance(rel, RelatedObject):
+            model = rel.model
+            opts = rel.opts
+        else:
+            model = rel.rel.to
+            opts = model._meta
+    try:
+        rel, model, direct, m2m = opts.get_field_by_name(parts[-1])
+    except FieldDoesNotExist:
+        return None
+    if not direct:
+        return rel.field.rel.to_field
+    return rel
+
 def filters_for_model(model, fields=None, exclude=None, filter_for_field=None):
-    field_list = []
+    field_dict = SortedDict()
     opts = model._meta
-    for f in sorted(opts.fields + opts.many_to_many):
-        if fields is not None and f.name not in fields:
+    if fields is None:
+        fields = [f.name for f in sorted(opts.fields + opts.many_to_many)]
+    for f in fields:
+        if exclude is not None and f in exclude:
             continue
-        if exclude is not None and f.name in exclude:
+        field = get_model_field(model, f)
+        if field is None:
+            field_dict[f] = None
             continue
-        filter_ = filter_for_field(f, f.name)
+        filter_ = filter_for_field(field, f)
         if filter_:
-            field_list.append((f.name, filter_))
-    field_dict = SortedDict(field_list)
-    if fields:
-        field_dict = SortedDict([(f, field_dict.get(f)) for f in fields if
-            (not exclude) or (exclude and f not in exclude)])
+            field_dict[f] = filter_
     return field_dict
 
 class FilterSetOptions(object):

django_filters/tests/__init__.py

@@ -1,6 +1,6 @@
 from tests import (GenericViewTests, InheritanceTest, ModelInheritanceTest,
     DateRangeFilterTest, FilterSetForm, AllValuesFilterTest, InitialValueTest,
-    filter_tests)
+    RelatedObjectTest, filter_tests)
 
 __test__ = {
     'filter_tests': filter_tests,

django_filters/tests/fixtures/test_data.json

@@ -1 +1 @@
-[{"pk": 1, "model": "tests.user", "fields": {"username": "alex", "status": 1, "first_name": "", "last_name": "", "favorite_books": [1, 2], "is_active": false}}, {"pk": 2, "model": "tests.user", "fields": {"username": "aaron", "status": 0, "first_name": "", "last_name": "", "favorite_books": [1, 3], "is_active": false}}, {"pk": 3, "model": "tests.user", "fields": {"username": "jacob", "status": 0, "first_name": "", "last_name": "", "favorite_books": [], "is_active": true}}, {"pk": 1, "model": "tests.comment", "fields": {"date": "2009-01-30", "text": "super awesome!", "time": "03:04:05", "author": 1}}, {"pk": 2, "model": "tests.comment", "fields": {"date": "2009-01-27", "text": "psycadelic!", "time": "05:04:03", "author": 2}}, {"pk": 3, "model": "tests.comment", "fields": {"date": "2008-12-31", "text": "funky fresh!", "time": "12:55:00", "author": 3}}, {"pk": 1, "model": "tests.book", "fields": {"average_rating": 4.7999999999999998, "price": "10", "title": "Ender's Game"}}, {"pk": 2, "model": "tests.book", "fields": {"average_rating": 4.5999999999999996, "price": "15", "title": "Rainbox Six"}}, {"pk": 3, "model": "tests.book", "fields": {"average_rating": 4.2999999999999998, "price": "20", "title": "Snowcrash"}}]
+[{"pk": 1, "model": "tests.user", "fields": {"username": "alex", "status": 1, "first_name": "", "last_name": "", "favorite_books": [1, 2], "is_active": false}}, {"pk": 2, "model": "tests.user", "fields": {"username": "aaron", "status": 0, "first_name": "", "last_name": "", "favorite_books": [1, 3], "is_active": false}}, {"pk": 3, "model": "tests.user", "fields": {"username": "jacob", "status": 0, "first_name": "", "last_name": "", "favorite_books": [], "is_active": true}}, {"pk": 1, "model": "tests.comment", "fields": {"date": "2009-01-30", "text": "super awesome!", "time": "03:04:05", "author": 1}}, {"pk": 2, "model": "tests.comment", "fields": {"date": "2009-01-27", "text": "psycadelic!", "time": "05:04:03", "author": 2}}, {"pk": 3, "model": "tests.comment", "fields": {"date": "2008-12-31", "text": "funky fresh!", "time": "12:55:00", "author": 3}}, {"pk": 1, "model": "tests.article", "fields": {"author": 1, "published": "2009-07-08 00:00:00"}}, {"pk": 2, "model": "tests.article", "fields": {"author": 1, "published": "2009-08-08 00:00:00"}}, {"pk": 3, "model": "tests.article", "fields": {"author": 3, "published": "2009-09-03 00:00:00"}}, {"pk": 1, "model": "tests.book", "fields": {"average_rating": 4.7999999999999998, "price": "10", "title": "Ender's Game"}}, {"pk": 2, "model": "tests.book", "fields": {"average_rating": 4.5999999999999996, "price": "15", "title": "Rainbox Six"}}, {"pk": 3, "model": "tests.book", "fields": {"average_rating": 4.2999999999999998, "price": "20", "title": "Snowcrash"}}]

django_filters/tests/models.py

@@ -2,6 +2,7 @@
 
 from django.db import models
 
+
 STATUS_CHOICES = (
     (0, 'Regular'),
     (1, 'Admin'),
@@ -31,8 +32,11 @@ class Comment(models.Model):
     def __unicode__(self):
         return "%s said %s" % (self.author, self.text[:25])
 
+
 class Article(models.Model):
     published = models.DateTimeField()
+    author = models.ForeignKey(User, null=True)
+
 
 class Book(models.Model):
     title = models.CharField(max_length=100)

django_filters/tests/tests.py

@@ -103,6 +103,24 @@ class Meta:
         self.assertEqual(list(F().qs), [User.objects.get(username='alex')])
         self.assertEqual(list(F({'status': 0})), list(User.objects.filter(status=0)))
 
+
+class RelatedObjectTest(TestCase):
+    fixtures = ['test_data']
+    
+    def test_foreignkey(self):
+        class F(django_filters.FilterSet):
+            class Meta:
+                model = Article
+                fields = ['author__username']
+        self.assertEqual(F.base_filters.keys(), ['author__username'])
+        form_html = ('<tr><th><label for="id_author__username">Username:</label>'
+            '</th><td><input type="text" name="author__username" '
+            'id="id_author__username" /></td></tr>')
+        self.assertEqual(str(F().form), form_html)
+        self.assertEqual(F({'author__username': 'alex'}).qs.count(), 2)
+        self.assertEqual(F({'author__username': 'jacob'}).qs.count(), 1)
+
+
 filter_tests = """
 >>> from datetime import datetime
 >>> from django import forms

docs/usage.txt

@@ -95,6 +95,10 @@ The inner ``Meta`` class also takes an optional ``form`` argument.  This is a
 form class from which ``FilterSet.form`` will subclass.  This works similar to
 the ``form`` option on a ``ModelAdmin.``
 
+Items in the ``fields`` sequence in the ``Meta`` class may include 
+"relationship paths" using Django's ``__`` syntax to filter on fields on a 
+related model.
+
 If you want to use a custom widget, or in any other way overide the ordering
 field you can overide the ``get_ordering_field()`` method on a ``FilterSet``.
 This method just needs to return a Form Field.