debian-django-haystack/haystack/indexes.py

498 lines
17 KiB
Python

# encoding: utf-8
from __future__ import absolute_import, division, print_function, unicode_literals
import copy
import threading
import warnings
from django.core.exceptions import ImproperlyConfigured
from django.utils.six import with_metaclass
from haystack import connection_router, connections
from haystack.constants import DEFAULT_ALIAS, DJANGO_CT, DJANGO_ID, ID, Indexable
from haystack.fields import *
from haystack.manager import SearchIndexManager
from haystack.utils import get_facet_field_name, get_identifier, get_model_ct
try:
from django.utils.encoding import force_text
except ImportError:
from django.utils.encoding import force_unicode as force_text
class DeclarativeMetaclass(type):
def __new__(cls, name, bases, attrs):
attrs['fields'] = {}
# Inherit any fields from parent(s).
try:
parents = [b for b in bases if issubclass(b, SearchIndex)]
# Simulate the MRO.
parents.reverse()
for p in parents:
fields = getattr(p, 'fields', None)
if fields:
attrs['fields'].update(fields)
except NameError:
pass
# Build a dictionary of faceted fields for cross-referencing.
facet_fields = {}
for field_name, obj in attrs.items():
# Only need to check the FacetFields.
if hasattr(obj, 'facet_for'):
if not obj.facet_for in facet_fields:
facet_fields[obj.facet_for] = []
facet_fields[obj.facet_for].append(field_name)
built_fields = {}
for field_name, obj in attrs.items():
if isinstance(obj, SearchField):
field = attrs[field_name]
field.set_instance_name(field_name)
built_fields[field_name] = field
# Only check non-faceted fields for the following info.
if not hasattr(field, 'facet_for'):
if field.faceted == True:
# If no other field is claiming this field as
# ``facet_for``, create a shadow ``FacetField``.
if not field_name in facet_fields:
shadow_facet_name = get_facet_field_name(field_name)
shadow_facet_field = field.facet_class(facet_for=field_name)
shadow_facet_field.set_instance_name(shadow_facet_name)
built_fields[shadow_facet_name] = shadow_facet_field
attrs['fields'].update(built_fields)
# Assigning default 'objects' query manager if it does not already exist
if not 'objects' in attrs:
try:
attrs['objects'] = SearchIndexManager(attrs['Meta'].index_label)
except (KeyError, AttributeError):
attrs['objects'] = SearchIndexManager(DEFAULT_ALIAS)
return super(DeclarativeMetaclass, cls).__new__(cls, name, bases, attrs)
class SearchIndex(with_metaclass(DeclarativeMetaclass, threading.local)):
"""
Base class for building indexes.
An example might look like this::
import datetime
from haystack import indexes
from myapp.models import Note
class NoteIndex(indexes.SearchIndex, indexes.Indexable):
text = indexes.CharField(document=True, use_template=True)
author = indexes.CharField(model_attr='user')
pub_date = indexes.DateTimeField(model_attr='pub_date')
def get_model(self):
return Note
def index_queryset(self, using=None):
return self.get_model().objects.filter(pub_date__lte=datetime.datetime.now())
"""
def __init__(self):
self.prepared_data = None
content_fields = []
self.field_map = dict()
for field_name, field in self.fields.items():
#form field map
self.field_map[field.index_fieldname] = field_name
if field.document is True:
content_fields.append(field_name)
if not len(content_fields) == 1:
raise SearchFieldError("The index '%s' must have one (and only one) SearchField with document=True." % self.__class__.__name__)
def get_model(self):
"""
Should return the ``Model`` class (not an instance) that the rest of the
``SearchIndex`` should use.
This method is required & you must override it to return the correct class.
"""
raise NotImplementedError("You must provide a 'model' method for the '%r' index." % self)
def index_queryset(self, using=None):
"""
Get the default QuerySet to index when doing a full update.
Subclasses can override this method to avoid indexing certain objects.
"""
return self.get_model()._default_manager.all()
def read_queryset(self, using=None):
"""
Get the default QuerySet for read actions.
Subclasses can override this method to work with other managers.
Useful when working with default managers that filter some objects.
"""
return self.index_queryset(using=using)
def build_queryset(self, using=None, start_date=None, end_date=None):
"""
Get the default QuerySet to index when doing an index update.
Subclasses can override this method to take into account related
model modification times.
The default is to use ``SearchIndex.index_queryset`` and filter
based on ``SearchIndex.get_updated_field``
"""
extra_lookup_kwargs = {}
model = self.get_model()
updated_field = self.get_updated_field()
update_field_msg = ("No updated date field found for '%s' "
"- not restricting by age.") % model.__name__
if start_date:
if updated_field:
extra_lookup_kwargs['%s__gte' % updated_field] = start_date
else:
warnings.warn(update_field_msg)
if end_date:
if updated_field:
extra_lookup_kwargs['%s__lte' % updated_field] = end_date
else:
warnings.warn(update_field_msg)
index_qs = None
if hasattr(self, 'get_queryset'):
warnings.warn("'SearchIndex.get_queryset' was deprecated in Haystack v2. Please rename the method 'index_queryset'.")
index_qs = self.get_queryset()
else:
index_qs = self.index_queryset(using=using)
if not hasattr(index_qs, 'filter'):
raise ImproperlyConfigured("The '%r' class must return a 'QuerySet' in the 'index_queryset' method." % self)
# `.select_related()` seems like a good idea here but can fail on
# nullable `ForeignKey` as well as what seems like other cases.
return index_qs.filter(**extra_lookup_kwargs).order_by(model._meta.pk.name)
def prepare(self, obj):
"""
Fetches and adds/alters data before indexing.
"""
self.prepared_data = {
ID: get_identifier(obj),
DJANGO_CT: get_model_ct(obj),
DJANGO_ID: force_text(obj.pk),
}
for field_name, field in self.fields.items():
# Use the possibly overridden name, which will default to the
# variable name of the field.
self.prepared_data[field.index_fieldname] = field.prepare(obj)
if hasattr(self, "prepare_%s" % field_name):
value = getattr(self, "prepare_%s" % field_name)(obj)
self.prepared_data[field.index_fieldname] = value
return self.prepared_data
def full_prepare(self, obj):
self.prepared_data = self.prepare(obj)
for field_name, field in self.fields.items():
# Duplicate data for faceted fields.
if getattr(field, 'facet_for', None):
source_field_name = self.fields[field.facet_for].index_fieldname
# If there's data there, leave it alone. Otherwise, populate it
# with whatever the related field has.
if self.prepared_data[field_name] is None and source_field_name in self.prepared_data:
self.prepared_data[field.index_fieldname] = self.prepared_data[source_field_name]
# Remove any fields that lack a value and are ``null=True``.
if field.null is True:
if self.prepared_data[field.index_fieldname] is None:
del(self.prepared_data[field.index_fieldname])
return self.prepared_data
def get_content_field(self):
"""Returns the field that supplies the primary document to be indexed."""
for field_name, field in self.fields.items():
if field.document is True:
return field.index_fieldname
def get_field_weights(self):
"""Returns a dict of fields with weight values"""
weights = {}
for field_name, field in self.fields.items():
if field.boost:
weights[field_name] = field.boost
return weights
def _get_backend(self, using):
if using is None:
try:
using = connection_router.for_write(index=self)[0]
except IndexError:
# There's no backend to handle it. Bomb out.
return None
return connections[using].get_backend()
def update(self, using=None):
"""
Updates the entire index.
If ``using`` is provided, it specifies which connection should be
used. Default relies on the routers to decide which backend should
be used.
"""
backend = self._get_backend(using)
if backend is not None:
backend.update(self, self.index_queryset(using=using))
def update_object(self, instance, using=None, **kwargs):
"""
Update the index for a single object. Attached to the class's
post-save hook.
If ``using`` is provided, it specifies which connection should be
used. Default relies on the routers to decide which backend should
be used.
"""
# Check to make sure we want to index this first.
if self.should_update(instance, **kwargs):
backend = self._get_backend(using)
if backend is not None:
backend.update(self, [instance])
def remove_object(self, instance, using=None, **kwargs):
"""
Remove an object from the index. Attached to the class's
post-delete hook.
If ``using`` is provided, it specifies which connection should be
used. Default relies on the routers to decide which backend should
be used.
"""
backend = self._get_backend(using)
if backend is not None:
backend.remove(instance, **kwargs)
def clear(self, using=None):
"""
Clears the entire index.
If ``using`` is provided, it specifies which connection should be
used. Default relies on the routers to decide which backend should
be used.
"""
backend = self._get_backend(using)
if backend is not None:
backend.clear(models=[self.get_model()])
def reindex(self, using=None):
"""
Completely clear the index for this model and rebuild it.
If ``using`` is provided, it specifies which connection should be
used. Default relies on the routers to decide which backend should
be used.
"""
self.clear(using=using)
self.update(using=using)
def get_updated_field(self):
"""
Get the field name that represents the updated date for the model.
If specified, this is used by the reindex command to filter out results
from the QuerySet, enabling you to reindex only recent records. This
method should either return None (reindex everything always) or a
string of the Model's DateField/DateTimeField name.
"""
return None
def should_update(self, instance, **kwargs):
"""
Determine if an object should be updated in the index.
It's useful to override this when an object may save frequently and
cause excessive reindexing. You should check conditions on the instance
and return False if it is not to be indexed.
By default, returns True (always reindex).
"""
return True
def load_all_queryset(self):
"""
Provides the ability to override how objects get loaded in conjunction
with ``SearchQuerySet.load_all``.
This is useful for post-processing the results from the query, enabling
things like adding ``select_related`` or filtering certain data.
By default, returns ``all()`` on the model's default manager.
"""
return self.get_model()._default_manager.all()
class BasicSearchIndex(SearchIndex):
text = CharField(document=True, use_template=True)
# End SearchIndexes
# Begin ModelSearchIndexes
def index_field_from_django_field(f, default=CharField):
"""
Returns the Haystack field type that would likely be associated with each
Django type.
"""
result = default
if f.get_internal_type() in ('DateField', 'DateTimeField'):
result = DateTimeField
elif f.get_internal_type() in ('BooleanField', 'NullBooleanField'):
result = BooleanField
elif f.get_internal_type() in ('CommaSeparatedIntegerField',):
result = MultiValueField
elif f.get_internal_type() in ('DecimalField', 'FloatField'):
result = FloatField
elif f.get_internal_type() in ('IntegerField', 'PositiveIntegerField', 'PositiveSmallIntegerField', 'SmallIntegerField'):
result = IntegerField
return result
class ModelSearchIndex(SearchIndex):
"""
Introspects the model assigned to it and generates a `SearchIndex` based on
the fields of that model.
In addition, it adds a `text` field that is the `document=True` field and
has `use_template=True` option set, just like the `BasicSearchIndex`.
Usage of this class might result in inferior `SearchIndex` objects, which
can directly affect your search results. Use this to establish basic
functionality and move to custom `SearchIndex` objects for better control.
At this time, it does not handle related fields.
"""
text = CharField(document=True, use_template=True)
# list of reserved field names
fields_to_skip = (ID, DJANGO_CT, DJANGO_ID, 'content', 'text')
def __init__(self, extra_field_kwargs=None):
self.model = None
self.prepared_data = None
content_fields = []
self.extra_field_kwargs = extra_field_kwargs or {}
# Introspect the model, adding/removing fields as needed.
# Adds/Excludes should happen only if the fields are not already
# defined in `self.fields`.
self._meta = getattr(self, 'Meta', None)
if self._meta:
self.model = getattr(self._meta, 'model', None)
fields = getattr(self._meta, 'fields', [])
excludes = getattr(self._meta, 'excludes', [])
# Add in the new fields.
self.fields.update(self.get_fields(fields, excludes))
for field_name, field in self.fields.items():
if field.document is True:
content_fields.append(field_name)
if not len(content_fields) == 1:
raise SearchFieldError("The index '%s' must have one (and only one) SearchField with document=True." % self.__class__.__name__)
def should_skip_field(self, field):
"""
Given a Django model field, return if it should be included in the
contributed SearchFields.
"""
# Skip fields in skip list
if field.name in self.fields_to_skip:
return True
# Ignore certain fields (AutoField, related fields).
if field.primary_key or getattr(field, 'rel'):
return True
return False
def get_model(self):
return self.model
def get_index_fieldname(self, f):
"""
Given a Django field, return the appropriate index fieldname.
"""
return f.name
def get_fields(self, fields=None, excludes=None):
"""
Given any explicit fields to include and fields to exclude, add
additional fields based on the associated model.
"""
final_fields = {}
fields = fields or []
excludes = excludes or []
for f in self.model._meta.fields:
# If the field name is already present, skip
if f.name in self.fields:
continue
# If field is not present in explicit field listing, skip
if fields and f.name not in fields:
continue
# If field is in exclude list, skip
if excludes and f.name in excludes:
continue
if self.should_skip_field(f):
continue
index_field_class = index_field_from_django_field(f)
kwargs = copy.copy(self.extra_field_kwargs)
kwargs.update({
'model_attr': f.name,
})
if f.null is True:
kwargs['null'] = True
if f.has_default():
kwargs['default'] = f.default
final_fields[f.name] = index_field_class(**kwargs)
final_fields[f.name].set_instance_name(self.get_index_fieldname(f))
return final_fields