Removed GeoWhereNode, obsoleted by GISLookup

This commit is contained in:
Claude Paroz 2014-05-24 16:18:45 +02:00
parent b8fc167b32
commit 3caf957ed5
4 changed files with 49 additions and 103 deletions

View File

@ -1,10 +1,51 @@
from django.db.models.constants import LOOKUP_SEP
from django.db.models.fields import FieldDoesNotExist
from django.db.models.lookups import Lookup
from django.db.models.sql.expressions import SQLEvaluator
class GISLookup(Lookup):
@classmethod
def _check_geo_field(cls, opts, lookup):
"""
Utility for checking the given lookup with the given model options.
The lookup is a string either specifying the geographic field, e.g.
'point, 'the_geom', or a related lookup on a geographic field like
'address__point'.
If a GeometryField exists according to the given lookup on the model
options, it will be returned. Otherwise returns None.
"""
from django.contrib.gis.db.models.fields import GeometryField
# This takes into account the situation where the lookup is a
# lookup to a related geographic field, e.g., 'address__point'.
field_list = lookup.split(LOOKUP_SEP)
# Reversing so list operates like a queue of related lookups,
# and popping the top lookup.
field_list.reverse()
fld_name = field_list.pop()
try:
geo_fld = opts.get_field(fld_name)
# If the field list is still around, then it means that the
# lookup was for a geometry field across a relationship --
# thus we keep on getting the related model options and the
# model field associated with the next field in the list
# until there's no more left.
while len(field_list):
opts = geo_fld.rel.to._meta
geo_fld = opts.get_field(field_list.pop())
except (FieldDoesNotExist, AttributeError):
return False
# Finally, make sure we got a Geographic field and return.
if isinstance(geo_fld, GeometryField):
return geo_fld
else:
return False
def as_sql(self, qn, connection):
from django.contrib.gis.db.models.sql import GeoWhereNode
# We use the same approach as was used by GeoWhereNode. It would
# be a good idea to upgrade GIS to use similar code that is used
# for other lookups.
@ -12,7 +53,7 @@ class GISLookup(Lookup):
# Make sure the F Expression destination field exists, and
# set an `srid` attribute with the same as that of the
# destination.
geo_fld = GeoWhereNode._check_geo_field(self.rhs.opts, self.rhs.expression.name)
geo_fld = self._check_geo_field(self.rhs.opts, self.rhs.expression.name)
if not geo_fld:
raise ValueError('No geographic field found in expression.')
self.rhs.srid = geo_fld.srid

View File

@ -1,7 +1,6 @@
from django.contrib.gis.db.models.sql.conversion import AreaField, DistanceField, GeomField
from django.contrib.gis.db.models.sql.query import GeoQuery
from django.contrib.gis.db.models.sql.where import GeoWhereNode
__all__ = [
'AreaField', 'DistanceField', 'GeomField', 'GeoQuery', 'GeoWhereNode',
'AreaField', 'DistanceField', 'GeomField', 'GeoQuery',
]

View File

@ -3,9 +3,9 @@ from django.db.models.query import sql
from django.contrib.gis.db.models.constants import ALL_TERMS
from django.contrib.gis.db.models.fields import GeometryField
from django.contrib.gis.db.models.lookups import GISLookup
from django.contrib.gis.db.models.sql import aggregates as gis_aggregates
from django.contrib.gis.db.models.sql.conversion import AreaField, DistanceField, GeomField
from django.contrib.gis.db.models.sql.where import GeoWhereNode
from django.contrib.gis.geometry.backend import Geometry
from django.contrib.gis.measure import Area, Distance
@ -21,11 +21,10 @@ class GeoQuery(sql.Query):
compiler = 'GeoSQLCompiler'
#### Methods overridden from the base Query class ####
def __init__(self, model, where=GeoWhereNode):
super(GeoQuery, self).__init__(model, where)
def __init__(self, model):
super(GeoQuery, self).__init__(model) #, where)
# The following attributes are customized for the GeoQuerySet.
# The GeoWhereNode and SpatialBackend classes contain backend-specific
# routines and functions.
# The SpatialBackend classes contain backend-specific routines and functions.
self.custom_select = {}
self.transformed_srid = None
self.extra_select_fields = {}
@ -108,4 +107,4 @@ class GeoQuery(sql.Query):
else:
# Otherwise, check by the given field name -- which may be
# a lookup to a _related_ geographic field.
return GeoWhereNode._check_geo_field(self.model._meta, field_name)
return GISLookup._check_geo_field(self.model._meta, field_name)

View File

@ -1,93 +0,0 @@
from django.db.models.constants import LOOKUP_SEP
from django.db.models.fields import FieldDoesNotExist
from django.db.models.sql.expressions import SQLEvaluator
from django.db.models.sql.where import Constraint, WhereNode
from django.contrib.gis.db.models.fields import GeometryField
class GeoConstraint(Constraint):
"""
This subclass overrides `process` to better handle geographic SQL
construction.
"""
def __init__(self, init_constraint):
self.alias = init_constraint.alias
self.col = init_constraint.col
self.field = init_constraint.field
def process(self, lookup_type, value, connection):
if isinstance(value, SQLEvaluator):
# Make sure the F Expression destination field exists, and
# set an `srid` attribute with the same as that of the
# destination.
geo_fld = GeoWhereNode._check_geo_field(value.opts, value.expression.name)
if not geo_fld:
raise ValueError('No geographic field found in expression.')
value.srid = geo_fld.srid
db_type = self.field.db_type(connection=connection)
params = self.field.get_db_prep_lookup(lookup_type, value, connection=connection)
return (self.alias, self.col, db_type), params
class GeoWhereNode(WhereNode):
"""
Used to represent the SQL where-clause for spatial databases --
these are tied to the GeoQuery class that created it.
"""
def _prepare_data(self, data):
if isinstance(data, (list, tuple)):
obj, lookup_type, value = data
if (isinstance(obj, Constraint) and
isinstance(obj.field, GeometryField)):
data = (GeoConstraint(obj), lookup_type, value)
return super(GeoWhereNode, self)._prepare_data(data)
def make_atom(self, child, qn, connection):
lvalue, lookup_type, value_annot, params_or_value = child
if isinstance(lvalue, GeoConstraint):
data, params = lvalue.process(lookup_type, params_or_value, connection)
spatial_sql, spatial_params = connection.ops.spatial_lookup_sql(
data, lookup_type, params_or_value, lvalue.field, qn)
return spatial_sql, spatial_params + params
else:
return super(GeoWhereNode, self).make_atom(child, qn, connection)
@classmethod
def _check_geo_field(cls, opts, lookup):
"""
Utility for checking the given lookup with the given model options.
The lookup is a string either specifying the geographic field, e.g.
'point, 'the_geom', or a related lookup on a geographic field like
'address__point'.
If a GeometryField exists according to the given lookup on the model
options, it will be returned. Otherwise returns None.
"""
# This takes into account the situation where the lookup is a
# lookup to a related geographic field, e.g., 'address__point'.
field_list = lookup.split(LOOKUP_SEP)
# Reversing so list operates like a queue of related lookups,
# and popping the top lookup.
field_list.reverse()
fld_name = field_list.pop()
try:
geo_fld = opts.get_field(fld_name)
# If the field list is still around, then it means that the
# lookup was for a geometry field across a relationship --
# thus we keep on getting the related model options and the
# model field associated with the next field in the list
# until there's no more left.
while len(field_list):
opts = geo_fld.rel.to._meta
geo_fld = opts.get_field(field_list.pop())
except (FieldDoesNotExist, AttributeError):
return False
# Finally, make sure we got a Geographic field and return.
if isinstance(geo_fld, GeometryField):
return geo_fld
else:
return False