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from django.db import connections
from django.db.models.query import QuerySet, ValuesQuerySet, ValuesListQuerySet
from django.contrib.gis import memoryview
from django.contrib.gis.db.models import aggregates
from django.contrib.gis.db.models.fields import get_srid_info, PointField, LineStringField
from django.contrib.gis.db.models.sql import AreaField, DistanceField, GeomField, GeoQuery
from django.contrib.gis.geometry.backend import Geometry
from django.contrib.gis.measure import Area, Distance
from django.utils import six
class GeoQuerySet(QuerySet):
"The Geographic QuerySet."
### Methods overloaded from QuerySet ###
def __init__(self, model=None, query=None, using=None):
super(GeoQuerySet, self).__init__(model=model, query=query, using=using)
self.query = query or GeoQuery(self.model)
def values(self, *fields):
return self._clone(klass=GeoValuesQuerySet, setup=True, _fields=fields)
def values_list(self, *fields, **kwargs):
flat = kwargs.pop('flat', False)
if kwargs:
raise TypeError('Unexpected keyword arguments to values_list: %s'
% (list(kwargs),))
if flat and len(fields) > 1:
raise TypeError("'flat' is not valid when values_list is called with more than one field.")
return self._clone(klass=GeoValuesListQuerySet, setup=True, flat=flat,
_fields=fields)
### GeoQuerySet Methods ###
def area(self, tolerance=0.05, **kwargs):
"""
Returns the area of the geographic field in an `area` attribute on
each element of this GeoQuerySet.
"""
# Peforming setup here rather than in `_spatial_attribute` so that
# we can get the units for `AreaField`.
procedure_args, geo_field = self._spatial_setup('area', field_name=kwargs.get('field_name', None))
s = {'procedure_args' : procedure_args,
'geo_field' : geo_field,
'setup' : False,
}
connection = connections[self.db]
backend = connection.ops
if backend.oracle:
s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
s['procedure_args']['tolerance'] = tolerance
s['select_field'] = AreaField('sq_m') # Oracle returns area in units of meters.
elif backend.postgis or backend.spatialite:
if backend.geography:
# Geography fields support area calculation, returns square meters.
s['select_field'] = AreaField('sq_m')
elif not geo_field.geodetic(connection):
# Getting the area units of the geographic field.
s['select_field'] = AreaField(Area.unit_attname(geo_field.units_name(connection)))
else:
# TODO: Do we want to support raw number areas for geodetic fields?
raise Exception('Area on geodetic coordinate systems not supported.')
return self._spatial_attribute('area', s, **kwargs)
def centroid(self, **kwargs):
"""
Returns the centroid of the geographic field in a `centroid`
attribute on each element of this GeoQuerySet.
"""
return self._geom_attribute('centroid', **kwargs)
def collect(self, **kwargs):
"""
Performs an aggregate collect operation on the given geometry field.
This is analagous to a union operation, but much faster because
boundaries are not dissolved.
"""
return self._spatial_aggregate(aggregates.Collect, **kwargs)
def difference(self, geom, **kwargs):
"""
Returns the spatial difference of the geographic field in a `difference`
attribute on each element of this GeoQuerySet.
"""
return self._geomset_attribute('difference', geom, **kwargs)
def distance(self, geom, **kwargs):
"""
Returns the distance from the given geographic field name to the
given geometry in a `distance` attribute on each element of the
GeoQuerySet.
Keyword Arguments:
`spheroid` => If the geometry field is geodetic and PostGIS is
the spatial database, then the more accurate
spheroid calculation will be used instead of the
quicker sphere calculation.
`tolerance` => Used only for Oracle. The tolerance is
in meters -- a default of 5 centimeters (0.05)
is used.
"""
return self._distance_attribute('distance', geom, **kwargs)
def envelope(self, **kwargs):
"""
Returns a Geometry representing the bounding box of the
Geometry field in an `envelope` attribute on each element of
the GeoQuerySet.
"""
return self._geom_attribute('envelope', **kwargs)
def extent(self, **kwargs):
"""
Returns the extent (aggregate) of the features in the GeoQuerySet. The
extent will be returned as a 4-tuple, consisting of (xmin, ymin, xmax, ymax).
"""
return self._spatial_aggregate(aggregates.Extent, **kwargs)
def extent3d(self, **kwargs):
"""
Returns the aggregate extent, in 3D, of the features in the
GeoQuerySet. It is returned as a 6-tuple, comprising:
(xmin, ymin, zmin, xmax, ymax, zmax).
"""
return self._spatial_aggregate(aggregates.Extent3D, **kwargs)
def force_rhr(self, **kwargs):
"""
Returns a modified version of the Polygon/MultiPolygon in which
all of the vertices follow the Right-Hand-Rule. By default,
this is attached as the `force_rhr` attribute on each element
of the GeoQuerySet.
"""
return self._geom_attribute('force_rhr', **kwargs)
def geojson(self, precision=8, crs=False, bbox=False, **kwargs):
"""
Returns a GeoJSON representation of the geomtry field in a `geojson`
attribute on each element of the GeoQuerySet.
The `crs` and `bbox` keywords may be set to True if the users wants
the coordinate reference system and the bounding box to be included
in the GeoJSON representation of the geometry.
"""
backend = connections[self.db].ops
if not backend.geojson:
raise NotImplementedError('Only PostGIS 1.3.4+ and SpatiaLite 3.0+'
'supports GeoJSON serialization.')
if not isinstance(precision, six.integer_types):
raise TypeError('Precision keyword must be set with an integer.')
# Setting the options flag -- which depends on which version of
# PostGIS we're using. SpatiaLite only uses the first group of options.
if backend.spatial_version >= (1, 4, 0):
options = 0
if crs and bbox: options = 3
elif bbox: options = 1
elif crs: options = 2
else:
options = 0
if crs and bbox: options = 3
elif crs: options = 1
elif bbox: options = 2
s = {'desc' : 'GeoJSON',
'procedure_args' : {'precision' : precision, 'options' : options},
'procedure_fmt' : '%(geo_col)s,%(precision)s,%(options)s',
}
return self._spatial_attribute('geojson', s, **kwargs)
def geohash(self, precision=20, **kwargs):
"""
Returns a GeoHash representation of the given field in a `geohash`
attribute on each element of the GeoQuerySet.
The `precision` keyword may be used to custom the number of
_characters_ used in the output GeoHash, the default is 20.
"""
s = {'desc' : 'GeoHash',
'procedure_args': {'precision': precision},
'procedure_fmt': '%(geo_col)s,%(precision)s',
}
return self._spatial_attribute('geohash', s, **kwargs)
def gml(self, precision=8, version=2, **kwargs):
"""
Returns GML representation of the given field in a `gml` attribute
on each element of the GeoQuerySet.
"""
backend = connections[self.db].ops
s = {'desc' : 'GML', 'procedure_args' : {'precision' : precision}}
if backend.postgis:
# PostGIS AsGML() aggregate function parameter order depends on the
# version -- uggh.
if backend.spatial_version > (1, 3, 1):
procedure_fmt = '%(version)s,%(geo_col)s,%(precision)s'
else:
procedure_fmt = '%(geo_col)s,%(precision)s,%(version)s'
s['procedure_args'] = {'precision' : precision, 'version' : version}
return self._spatial_attribute('gml', s, **kwargs)
def intersection(self, geom, **kwargs):
"""
Returns the spatial intersection of the Geometry field in
an `intersection` attribute on each element of this
GeoQuerySet.
"""
return self._geomset_attribute('intersection', geom, **kwargs)
def kml(self, **kwargs):
"""
Returns KML representation of the geometry field in a `kml`
attribute on each element of this GeoQuerySet.
"""
s = {'desc' : 'KML',
'procedure_fmt' : '%(geo_col)s,%(precision)s',
'procedure_args' : {'precision' : kwargs.pop('precision', 8)},
}
return self._spatial_attribute('kml', s, **kwargs)
def length(self, **kwargs):
"""
Returns the length of the geometry field as a `Distance` object
stored in a `length` attribute on each element of this GeoQuerySet.
"""
return self._distance_attribute('length', None, **kwargs)
def make_line(self, **kwargs):
"""
Creates a linestring from all of the PointField geometries in the
this GeoQuerySet and returns it. This is a spatial aggregate
method, and thus returns a geometry rather than a GeoQuerySet.
"""
return self._spatial_aggregate(aggregates.MakeLine, geo_field_type=PointField, **kwargs)
def mem_size(self, **kwargs):
"""
Returns the memory size (number of bytes) that the geometry field takes
in a `mem_size` attribute on each element of this GeoQuerySet.
"""
return self._spatial_attribute('mem_size', {}, **kwargs)
def num_geom(self, **kwargs):
"""
Returns the number of geometries if the field is a
GeometryCollection or Multi* Field in a `num_geom`
attribute on each element of this GeoQuerySet; otherwise
the sets with None.
"""
return self._spatial_attribute('num_geom', {}, **kwargs)
def num_points(self, **kwargs):
"""
Returns the number of points in the first linestring in the
Geometry field in a `num_points` attribute on each element of
this GeoQuerySet; otherwise sets with None.
"""
return self._spatial_attribute('num_points', {}, **kwargs)
def perimeter(self, **kwargs):
"""
Returns the perimeter of the geometry field as a `Distance` object
stored in a `perimeter` attribute on each element of this GeoQuerySet.
"""
return self._distance_attribute('perimeter', None, **kwargs)
def point_on_surface(self, **kwargs):
"""
Returns a Point geometry guaranteed to lie on the surface of the
Geometry field in a `point_on_surface` attribute on each element
of this GeoQuerySet; otherwise sets with None.
"""
return self._geom_attribute('point_on_surface', **kwargs)
def reverse_geom(self, **kwargs):
"""
Reverses the coordinate order of the geometry, and attaches as a
`reverse` attribute on each element of this GeoQuerySet.
"""
s = {'select_field' : GeomField(),}
kwargs.setdefault('model_att', 'reverse_geom')
if connections[self.db].ops.oracle:
s['geo_field_type'] = LineStringField
return self._spatial_attribute('reverse', s, **kwargs)
def scale(self, x, y, z=0.0, **kwargs):
"""
Scales the geometry to a new size by multiplying the ordinates
with the given x,y,z scale factors.
"""
if connections[self.db].ops.spatialite:
if z != 0.0:
raise NotImplementedError('SpatiaLite does not support 3D scaling.')
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s',
'procedure_args' : {'x' : x, 'y' : y},
'select_field' : GeomField(),
}
else:
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
'select_field' : GeomField(),
}
return self._spatial_attribute('scale', s, **kwargs)
def snap_to_grid(self, *args, **kwargs):
"""
Snap all points of the input geometry to the grid. How the
geometry is snapped to the grid depends on how many arguments
were given:
- 1 argument : A single size to snap both the X and Y grids to.
- 2 arguments: X and Y sizes to snap the grid to.
- 4 arguments: X, Y sizes and the X, Y origins.
"""
if False in [isinstance(arg, (float,) + six.integer_types) for arg in args]:
raise TypeError('Size argument(s) for the grid must be a float or integer values.')
nargs = len(args)
if nargs == 1:
size = args[0]
procedure_fmt = '%(geo_col)s,%(size)s'
procedure_args = {'size' : size}
elif nargs == 2:
xsize, ysize = args
procedure_fmt = '%(geo_col)s,%(xsize)s,%(ysize)s'
procedure_args = {'xsize' : xsize, 'ysize' : ysize}
elif nargs == 4:
xsize, ysize, xorigin, yorigin = args
procedure_fmt = '%(geo_col)s,%(xorigin)s,%(yorigin)s,%(xsize)s,%(ysize)s'
procedure_args = {'xsize' : xsize, 'ysize' : ysize,
'xorigin' : xorigin, 'yorigin' : yorigin}
else:
raise ValueError('Must provide 1, 2, or 4 arguments to `snap_to_grid`.')
s = {'procedure_fmt' : procedure_fmt,
'procedure_args' : procedure_args,
'select_field' : GeomField(),
}
return self._spatial_attribute('snap_to_grid', s, **kwargs)
def svg(self, relative=False, precision=8, **kwargs):
"""
Returns SVG representation of the geographic field in a `svg`
attribute on each element of this GeoQuerySet.
Keyword Arguments:
`relative` => If set to True, this will evaluate the path in
terms of relative moves (rather than absolute).
`precision` => May be used to set the maximum number of decimal
digits used in output (defaults to 8).
"""
relative = int(bool(relative))
if not isinstance(precision, six.integer_types):
raise TypeError('SVG precision keyword argument must be an integer.')
s = {'desc' : 'SVG',
'procedure_fmt' : '%(geo_col)s,%(rel)s,%(precision)s',
'procedure_args' : {'rel' : relative,
'precision' : precision,
}
}
return self._spatial_attribute('svg', s, **kwargs)
def sym_difference(self, geom, **kwargs):
"""
Returns the symmetric difference of the geographic field in a
`sym_difference` attribute on each element of this GeoQuerySet.
"""
return self._geomset_attribute('sym_difference', geom, **kwargs)
def translate(self, x, y, z=0.0, **kwargs):
"""
Translates the geometry to a new location using the given numeric
parameters as offsets.
"""
if connections[self.db].ops.spatialite:
if z != 0.0:
raise NotImplementedError('SpatiaLite does not support 3D translation.')
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s',
'procedure_args' : {'x' : x, 'y' : y},
'select_field' : GeomField(),
}
else:
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
'select_field' : GeomField(),
}
return self._spatial_attribute('translate', s, **kwargs)
def transform(self, srid=4326, **kwargs):
"""
Transforms the given geometry field to the given SRID. If no SRID is
provided, the transformation will default to using 4326 (WGS84).
"""
if not isinstance(srid, six.integer_types):
raise TypeError('An integer SRID must be provided.')
field_name = kwargs.get('field_name', None)
tmp, geo_field = self._spatial_setup('transform', field_name=field_name)
# Getting the selection SQL for the given geographic field.
field_col = self._geocol_select(geo_field, field_name)
# Why cascading substitutions? Because spatial backends like
# Oracle and MySQL already require a function call to convert to text, thus
# when there's also a transformation we need to cascade the substitutions.
# For example, 'SDO_UTIL.TO_WKTGEOMETRY(SDO_CS.TRANSFORM( ... )'
geo_col = self.query.custom_select.get(geo_field, field_col)
# Setting the key for the field's column with the custom SELECT SQL to
# override the geometry column returned from the database.
custom_sel = '%s(%s, %s)' % (connections[self.db].ops.transform, geo_col, srid)
# TODO: Should we have this as an alias?
# custom_sel = '(%s(%s, %s)) AS %s' % (SpatialBackend.transform, geo_col, srid, qn(geo_field.name))
self.query.transformed_srid = srid # So other GeoQuerySet methods
self.query.custom_select[geo_field] = custom_sel
return self._clone()
def union(self, geom, **kwargs):
"""
Returns the union of the geographic field with the given
Geometry in a `union` attribute on each element of this GeoQuerySet.
"""
return self._geomset_attribute('union', geom, **kwargs)
def unionagg(self, **kwargs):
"""
Performs an aggregate union on the given geometry field. Returns
None if the GeoQuerySet is empty. The `tolerance` keyword is for
Oracle backends only.
"""
return self._spatial_aggregate(aggregates.Union, **kwargs)
### Private API -- Abstracted DRY routines. ###
def _spatial_setup(self, att, desc=None, field_name=None, geo_field_type=None):
"""
Performs set up for executing the spatial function.
"""
# Does the spatial backend support this?
connection = connections[self.db]
func = getattr(connection.ops, att, False)
if desc is None: desc = att
if not func:
raise NotImplementedError('%s stored procedure not available on '
'the %s backend.' %
(desc, connection.ops.name))
# Initializing the procedure arguments.
procedure_args = {'function' : func}
# Is there a geographic field in the model to perform this
# operation on?
geo_field = self.query._geo_field(field_name)
if not geo_field:
raise TypeError('%s output only available on GeometryFields.' % func)
# If the `geo_field_type` keyword was used, then enforce that
# type limitation.
if not geo_field_type is None and not isinstance(geo_field, geo_field_type):
raise TypeError('"%s" stored procedures may only be called on %ss.' % (func, geo_field_type.__name__))
# Setting the procedure args.
procedure_args['geo_col'] = self._geocol_select(geo_field, field_name)
return procedure_args, geo_field
def _spatial_aggregate(self, aggregate, field_name=None,
geo_field_type=None, tolerance=0.05):
"""
DRY routine for calling aggregate spatial stored procedures and
returning their result to the caller of the function.
"""
# Getting the field the geographic aggregate will be called on.
geo_field = self.query._geo_field(field_name)
if not geo_field:
raise TypeError('%s aggregate only available on GeometryFields.' % aggregate.name)
# Checking if there are any geo field type limitations on this
# aggregate (e.g. ST_Makeline only operates on PointFields).
if not geo_field_type is None and not isinstance(geo_field, geo_field_type):
raise TypeError('%s aggregate may only be called on %ss.' % (aggregate.name, geo_field_type.__name__))
# Getting the string expression of the field name, as this is the
# argument taken by `Aggregate` objects.
agg_col = field_name or geo_field.name
# Adding any keyword parameters for the Aggregate object. Oracle backends
# in particular need an additional `tolerance` parameter.
agg_kwargs = {}
if connections[self.db].ops.oracle: agg_kwargs['tolerance'] = tolerance
# Calling the QuerySet.aggregate, and returning only the value of the aggregate.
return self.aggregate(geoagg=aggregate(agg_col, **agg_kwargs))['geoagg']
def _spatial_attribute(self, att, settings, field_name=None, model_att=None):
"""
DRY routine for calling a spatial stored procedure on a geometry column
and attaching its output as an attribute of the model.
Arguments:
att:
The name of the spatial attribute that holds the spatial
SQL function to call.
settings:
Dictonary of internal settings to customize for the spatial procedure.
Public Keyword Arguments:
field_name:
The name of the geographic field to call the spatial
function on. May also be a lookup to a geometry field
as part of a foreign key relation.
model_att:
The name of the model attribute to attach the output of
the spatial function to.
"""
# Default settings.
settings.setdefault('desc', None)
settings.setdefault('geom_args', ())
settings.setdefault('geom_field', None)
settings.setdefault('procedure_args', {})
settings.setdefault('procedure_fmt', '%(geo_col)s')
settings.setdefault('select_params', [])
connection = connections[self.db]
backend = connection.ops
# Performing setup for the spatial column, unless told not to.
if settings.get('setup', True):
default_args, geo_field = self._spatial_setup(att, desc=settings['desc'], field_name=field_name,
geo_field_type=settings.get('geo_field_type', None))
for k, v in six.iteritems(default_args): settings['procedure_args'].setdefault(k, v)
else:
geo_field = settings['geo_field']
# The attribute to attach to the model.
if not isinstance(model_att, six.string_types): model_att = att
# Special handling for any argument that is a geometry.
for name in settings['geom_args']:
# Using the field's get_placeholder() routine to get any needed
# transformation SQL.
geom = geo_field.get_prep_value(settings['procedure_args'][name])
params = geo_field.get_db_prep_lookup('contains', geom, connection=connection)
geom_placeholder = geo_field.get_placeholder(geom, connection)
# Replacing the procedure format with that of any needed
# transformation SQL.
old_fmt = '%%(%s)s' % name
new_fmt = geom_placeholder % '%%s'
settings['procedure_fmt'] = settings['procedure_fmt'].replace(old_fmt, new_fmt)
settings['select_params'].extend(params)
# Getting the format for the stored procedure.
fmt = '%%(function)s(%s)' % settings['procedure_fmt']
# If the result of this function needs to be converted.
if settings.get('select_field', False):
sel_fld = settings['select_field']
if isinstance(sel_fld, GeomField) and backend.select:
self.query.custom_select[model_att] = backend.select
if connection.ops.oracle:
sel_fld.empty_strings_allowed = False
self.query.extra_select_fields[model_att] = sel_fld
# Finally, setting the extra selection attribute with
# the format string expanded with the stored procedure
# arguments.
return self.extra(select={model_att : fmt % settings['procedure_args']},
select_params=settings['select_params'])
def _distance_attribute(self, func, geom=None, tolerance=0.05, spheroid=False, **kwargs):
"""
DRY routine for GeoQuerySet distance attribute routines.
"""
# Setting up the distance procedure arguments.
procedure_args, geo_field = self._spatial_setup(func, field_name=kwargs.get('field_name', None))
# If geodetic defaulting distance attribute to meters (Oracle and
# PostGIS spherical distances return meters). Otherwise, use the
# units of the geometry field.
connection = connections[self.db]
geodetic = geo_field.geodetic(connection)
geography = geo_field.geography
if geodetic:
dist_att = 'm'
else:
dist_att = Distance.unit_attname(geo_field.units_name(connection))
# Shortcut booleans for what distance function we're using and
# whether the geometry field is 3D.
distance = func == 'distance'
length = func == 'length'
perimeter = func == 'perimeter'
if not (distance or length or perimeter):
raise ValueError('Unknown distance function: %s' % func)
geom_3d = geo_field.dim == 3
# The field's get_db_prep_lookup() is used to get any
# extra distance parameters. Here we set up the
# parameters that will be passed in to field's function.
lookup_params = [geom or 'POINT (0 0)', 0]
# Getting the spatial backend operations.
backend = connection.ops
# If the spheroid calculation is desired, either by the `spheroid`
# keyword or when calculating the length of geodetic field, make
# sure the 'spheroid' distance setting string is passed in so we
# get the correct spatial stored procedure.
if spheroid or (backend.postgis and geodetic and
(not geography) and length):
lookup_params.append('spheroid')
lookup_params = geo_field.get_prep_value(lookup_params)
params = geo_field.get_db_prep_lookup('distance_lte', lookup_params, connection=connection)
# The `geom_args` flag is set to true if a geometry parameter was
# passed in.
geom_args = bool(geom)
if backend.oracle:
if distance:
procedure_fmt = '%(geo_col)s,%(geom)s,%(tolerance)s'
elif length or perimeter:
procedure_fmt = '%(geo_col)s,%(tolerance)s'
procedure_args['tolerance'] = tolerance
else:
# Getting whether this field is in units of degrees since the field may have
# been transformed via the `transform` GeoQuerySet method.
if self.query.transformed_srid:
u, unit_name, s = get_srid_info(self.query.transformed_srid, connection)
geodetic = unit_name in geo_field.geodetic_units
if backend.spatialite and geodetic:
raise ValueError('SQLite does not support linear distance calculations on geodetic coordinate systems.')
if distance:
if self.query.transformed_srid:
# Setting the `geom_args` flag to false because we want to handle
# transformation SQL here, rather than the way done by default
# (which will transform to the original SRID of the field rather
# than to what was transformed to).
geom_args = False
procedure_fmt = '%s(%%(geo_col)s, %s)' % (backend.transform, self.query.transformed_srid)
if geom.srid is None or geom.srid == self.query.transformed_srid:
# If the geom parameter srid is None, it is assumed the coordinates
# are in the transformed units. A placeholder is used for the
# geometry parameter. `GeomFromText` constructor is also needed
# to wrap geom placeholder for SpatiaLite.
if backend.spatialite:
procedure_fmt += ', %s(%%%%s, %s)' % (backend.from_text, self.query.transformed_srid)
else:
procedure_fmt += ', %%s'
else:
# We need to transform the geom to the srid specified in `transform()`,
# so wrapping the geometry placeholder in transformation SQL.
# SpatiaLite also needs geometry placeholder wrapped in `GeomFromText`
# constructor.
if backend.spatialite:
procedure_fmt += ', %s(%s(%%%%s, %s), %s)' % (backend.transform, backend.from_text,
geom.srid, self.query.transformed_srid)
else:
procedure_fmt += ', %s(%%%%s, %s)' % (backend.transform, self.query.transformed_srid)
else:
# `transform()` was not used on this GeoQuerySet.
procedure_fmt = '%(geo_col)s,%(geom)s'
if not geography and geodetic:
# Spherical distance calculation is needed (because the geographic
# field is geodetic). However, the PostGIS ST_distance_sphere/spheroid()
# procedures may only do queries from point columns to point geometries
# some error checking is required.
if not backend.geography:
if not isinstance(geo_field, PointField):
raise ValueError('Spherical distance calculation only supported on PointFields.')
if not str(Geometry(memoryview(params[0].ewkb)).geom_type) == 'Point':
raise ValueError('Spherical distance calculation only supported with Point Geometry parameters')
# The `function` procedure argument needs to be set differently for
# geodetic distance calculations.
if spheroid:
# Call to distance_spheroid() requires spheroid param as well.
procedure_fmt += ",'%(spheroid)s'"
procedure_args.update({'function' : backend.distance_spheroid, 'spheroid' : params[1]})
else:
procedure_args.update({'function' : backend.distance_sphere})
elif length or perimeter:
procedure_fmt = '%(geo_col)s'
if not geography and geodetic and length:
# There's no `length_sphere`, and `length_spheroid` also
# works on 3D geometries.
procedure_fmt += ",'%(spheroid)s'"
procedure_args.update({'function' : backend.length_spheroid, 'spheroid' : params[1]})
elif geom_3d and backend.postgis:
# Use 3D variants of perimeter and length routines on PostGIS.
if perimeter:
procedure_args.update({'function' : backend.perimeter3d})
elif length:
procedure_args.update({'function' : backend.length3d})
# Setting up the settings for `_spatial_attribute`.
s = {'select_field' : DistanceField(dist_att),
'setup' : False,
'geo_field' : geo_field,
'procedure_args' : procedure_args,
'procedure_fmt' : procedure_fmt,
}
if geom_args:
s['geom_args'] = ('geom',)
s['procedure_args']['geom'] = geom
elif geom:
# The geometry is passed in as a parameter because we handled
# transformation conditions in this routine.
s['select_params'] = [backend.Adapter(geom)]
return self._spatial_attribute(func, s, **kwargs)
def _geom_attribute(self, func, tolerance=0.05, **kwargs):
"""
DRY routine for setting up a GeoQuerySet method that attaches a
Geometry attribute (e.g., `centroid`, `point_on_surface`).
"""
s = {'select_field' : GeomField(),}
if connections[self.db].ops.oracle:
s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
s['procedure_args'] = {'tolerance' : tolerance}
return self._spatial_attribute(func, s, **kwargs)
def _geomset_attribute(self, func, geom, tolerance=0.05, **kwargs):
"""
DRY routine for setting up a GeoQuerySet method that attaches a
Geometry attribute and takes a Geoemtry parameter. This is used
for geometry set-like operations (e.g., intersection, difference,
union, sym_difference).
"""
s = {'geom_args' : ('geom',),
'select_field' : GeomField(),
'procedure_fmt' : '%(geo_col)s,%(geom)s',
'procedure_args' : {'geom' : geom},
}
if connections[self.db].ops.oracle:
s['procedure_fmt'] += ',%(tolerance)s'
s['procedure_args']['tolerance'] = tolerance
return self._spatial_attribute(func, s, **kwargs)
def _geocol_select(self, geo_field, field_name):
"""
Helper routine for constructing the SQL to select the geographic
column. Takes into account if the geographic field is in a
ForeignKey relation to the current model.
"""
opts = self.model._meta
if not geo_field in opts.fields:
# Is this operation going to be on a related geographic field?
# If so, it'll have to be added to the select related information
# (e.g., if 'location__point' was given as the field name).
self.query.add_select_related([field_name])
compiler = self.query.get_compiler(self.db)
compiler.pre_sql_setup()
rel_table, rel_col = self.query.related_select_cols[self.query.related_select_fields.index(geo_field)]
return compiler._field_column(geo_field, rel_table)
elif not geo_field in opts.local_fields:
# This geographic field is inherited from another model, so we have to
# use the db table for the _parent_ model instead.
tmp_fld, parent_model, direct, m2m = opts.get_field_by_name(geo_field.name)
return self.query.get_compiler(self.db)._field_column(geo_field, parent_model._meta.db_table)
else:
return self.query.get_compiler(self.db)._field_column(geo_field)
class GeoValuesQuerySet(ValuesQuerySet):
def __init__(self, *args, **kwargs):
super(GeoValuesQuerySet, self).__init__(*args, **kwargs)
# This flag tells `resolve_columns` to run the values through
# `convert_values`. This ensures that Geometry objects instead
# of string values are returned with `values()` or `values_list()`.
self.query.geo_values = True
class GeoValuesListQuerySet(GeoValuesQuerySet, ValuesListQuerySet):
pass
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