Merge pull request #62 from Princeton-CDH/chore/signal-dependencies

Handle more cases when identifying index dependencies for django models

parasolr/django/indexing.py

@@ -36,7 +36,7 @@ def index_data(self):
 from parasolr.indexing import Indexable
 
 try:
-    from django.db.models import Model
+    from django.db.models import Model, Manager
     from django.apps import apps
     from django.db.models.fields import related_descriptors
 except ImportError:
@@ -96,6 +96,16 @@ def get_related_model(model, name):
                         related_descriptors.ReverseManyToOneDescriptor):
             related_model = attr.rel.related_model
 
+        elif isinstance(attr,
+                        related_descriptors.ForwardManyToOneDescriptor):
+            # many to one, i.e. foreign key
+            related_model = attr.field.related_model
+
+        elif isinstance(attr, Manager):
+            # specific to django-taggit TaggableManager
+            if hasattr(attr.through, 'tag_model'):
+                related_model = attr.through.tag_model()
+
         if related_model:
             return related_model
 
@@ -129,7 +139,8 @@ def identify_index_dependencies(cls):
                 if hasattr(model, dep):
                     attr = getattr(model, dep)
                     if isinstance(
-                       attr, related_descriptors.ManyToManyDescriptor):
+                        attr, (Manager,
+                               related_descriptors.ManyToManyDescriptor)):
                         # add through model to many to many list
                         m2m.append(attr.through)
 

parasolr/django/signals.py

@@ -18,7 +18,7 @@ def ready(self):
 :class:`~parasolr.django.indexing.ModelIndexable` subclass with the
 dependencies and signals that should trigger reindexing.  Example::
 
-    class MyModel(Model, ModelIndexable):
+    class MyModel(ModelIndexable):
 
         index_depends_on = {
             'collections': {

parasolr/django/tests/test_django.py

@@ -5,8 +5,8 @@
 
 try:
     import django
+    from django.db.models import Manager
     from django.core.exceptions import ImproperlyConfigured
-    from django.db import models
     from django.test import override_settings
 
     from parasolr.django import SolrClient, SolrQuerySet, \
@@ -183,12 +183,22 @@ def test_get_related_model(caplog):
     assert ModelIndexable.get_related_model(
         IndexItem, 'owner_set__collections') == Collection
 
-    # foreign key is not currently supported; should warn
+    # foreign key is now supported!
+    assert ModelIndexable.get_related_model(
+        IndexItem, 'primary') == Collection
+
+    # use mock to test taggable manager behavior
+    mockitem = Mock()
+    mockitem.tags = Mock(spec=Manager, through=Mock())
+    mockitem.tags.through.tag_model.return_value = 'TagBase'
+    assert ModelIndexable.get_related_model(mockitem, 'tags') == \
+        'TagBase'
+
+    # if relation cannot be determined, should warn
     with caplog.at_level(logging.WARNING):
-        assert not ModelIndexable.get_related_model(IndexItem, 'primary')
+        assert not ModelIndexable.get_related_model(mockitem, 'foo')
         assert 'Unhandled related model' in caplog.text
 
-
 # these classes cannot be defined without django dependencies
 if django: