def area(self, tolerance=0.05, **kwargs):
"""
Returns the area of the geographic field in an `area` attribute on
each element of this GeoQuerySet.
"""
# Performing 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'))
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 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 get_area_att_for_field(self, field):
if field.geodetic(self.connection):
if self.connection.features.supports_area_geodetic:
return 'sq_m'
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
else:
units_name = field.units_name(self.connection)
if units_name:
return AreaMeasure.unit_attname(units_name)
def get_area_att_for_field(self, field):
if field.geodetic(self.connection):
if self.connection.features.supports_area_geodetic:
return 'sq_m'
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
else:
units_name = field.units_name(self.connection)
if units_name:
return AreaMeasure.unit_attname(units_name)
def as_sql(self, compiler, connection):
if connection.ops.geography:
self.output_field.area_att = 'sq_m'
else:
# Getting the area units of the geographic field.
source_fields = self.get_source_fields()
if len(source_fields):
source_field = source_fields[0]
if source_field.geodetic(connection):
# TODO: Do we want to support raw number areas for geodetic fields?
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
units_name = source_field.units_name(connection)
if units_name:
self.output_field.area_att = AreaMeasure.unit_attname(units_name)
return super(Area, self).as_sql(compiler, connection)
def as_sql(self, compiler, connection):
if connection.ops.geography:
# Geography fields support area calculation, returns square meters.
self.output_field = AreaField("sq_m")
elif not self.output_field.geodetic(connection):
# Getting the area units of the geographic field.
units = self.output_field.units_name(connection)
if units:
self.output_field = AreaField(AreaMeasure.unit_attname(self.output_field.units_name(connection)))
else:
self.output_field = FloatField()
else:
# TODO: Do we want to support raw number areas for geodetic fields?
raise NotImplementedError("Area on geodetic coordinate systems not supported.")
return super(Area, self).as_sql(compiler, connection)
def as_sql(self, compiler, connection, **extra_context):
if connection.ops.geography:
self.output_field.area_att = 'sq_m'
else:
# Getting the area units of the geographic field.
if self.geo_field.geodetic(connection):
if connection.features.supports_area_geodetic:
self.output_field.area_att = 'sq_m'
else:
# TODO: Do we want to support raw number areas for geodetic fields?
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
else:
units_name = self.geo_field.units_name(connection)
if units_name:
self.output_field.area_att = AreaMeasure.unit_attname(units_name)
return super().as_sql(compiler, connection, **extra_context)
def as_sql(self, compiler, connection):
if connection.ops.geography:
# Geography fields support area calculation, returns square meters.
self.output_field = AreaField('sq_m')
elif not self.output_field.geodetic(connection):
# Getting the area units of the geographic field.
units = self.output_field.units_name(connection)
if units:
self.output_field = AreaField(
AreaMeasure.unit_attname(self.output_field.units_name(connection))
)
else:
self.output_field = FloatField()
else:
# TODO: Do we want to support raw number areas for geodetic fields?
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
return super(Area, self).as_sql(compiler, connection)
def as_sql(self, compiler, connection, **extra_context):
if connection.ops.geography:
self.output_field.area_att = 'sq_m'
else:
# Getting the area units of the geographic field.
geo_field = self.geo_field
if geo_field.geodetic(connection):
if connection.features.supports_area_geodetic:
self.output_field.area_att = 'sq_m'
else:
# TODO: Do we want to support raw number areas for geodetic fields?
raise NotImplementedError('Area on geodetic coordinate systems not supported.')
else:
units_name = geo_field.units_name(connection)
if units_name:
self.output_field.area_att = AreaMeasure.unit_attname(units_name)
return super().as_sql(compiler, connection, **extra_context)
from decimal import Decimal
import warnings
