Load ../vendor/django into trunk/app/django.
from django.core.exceptions import ImproperlyConfigured
from django.db import connection
from django.db.models.query import sql, QuerySet, Q
from django.contrib.gis.db.backend import SpatialBackend
from django.contrib.gis.db.models.fields import GeometryField, PointField
from django.contrib.gis.db.models.sql import AreaField, DistanceField, GeomField, GeoQuery, GeoWhereNode
from django.contrib.gis.measure import Area, Distance
from django.contrib.gis.models import get_srid_info
qn = connection.ops.quote_name
# For backwards-compatibility; Q object should work just fine
# after queryset-refactor.
class GeoQ(Q): pass
class GeomSQL(object):
"Simple wrapper object for geometric SQL."
def __init__(self, geo_sql):
self.sql = geo_sql
def as_sql(self, *args, **kwargs):
return self.sql
class GeoQuerySet(QuerySet):
"The Geographic QuerySet."
def __init__(self, model=None, query=None):
super(GeoQuerySet, self).__init__(model=model, query=query)
self.query = query or GeoQuery(self.model, connection)
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,
}
if SpatialBackend.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 SpatialBackend.postgis:
if not geo_field.geodetic:
# Getting the area units of the geographic field.
s['select_field'] = AreaField(Area.unit_attname(geo_field._unit_name))
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 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).
"""
convert_extent = None
if SpatialBackend.postgis:
def convert_extent(box, geo_field):
# TODO: Parsing of BOX3D, Oracle support (patches welcome!)
# Box text will be something like "BOX(-90.0 30.0, -85.0 40.0)";
# parsing out and returning as a 4-tuple.
ll, ur = box[4:-1].split(',')
xmin, ymin = map(float, ll.split())
xmax, ymax = map(float, ur.split())
return (xmin, ymin, xmax, ymax)
elif SpatialBackend.oracle:
def convert_extent(wkt, geo_field):
raise NotImplementedError
return self._spatial_aggregate('extent', convert_func=convert_extent, **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.
"""
s = {'desc' : 'GML', 'procedure_args' : {'precision' : precision}}
if SpatialBackend.postgis:
# PostGIS AsGML() aggregate function parameter order depends on the
# version -- uggh.
major, minor1, minor2 = SpatialBackend.version
if major >= 1 and (minor1 > 3 or (minor1 == 3 and minor2 > 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.
"""
kwargs['geo_field_type'] = PointField
kwargs['agg_field'] = GeometryField
return self._spatial_aggregate('make_line', **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 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.
"""
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 svg(self, **kwargs):
"""
Returns SVG representation of the geographic field in a `svg`
attribute on each element of this GeoQuerySet.
"""
s = {'desc' : 'SVG',
'procedure_fmt' : '%(geo_col)s,%(rel)s,%(precision)s',
'procedure_args' : {'rel' : int(kwargs.pop('relative', 0)),
'precision' : kwargs.pop('precision', 8)},
}
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.
"""
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, (int, long)):
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)' % (SpatialBackend.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.
"""
kwargs['agg_field'] = GeometryField
return self._spatial_aggregate('unionagg', **kwargs)
### Private API -- Abstracted DRY routines. ###
def _spatial_setup(self, att, aggregate=False, desc=None, field_name=None, geo_field_type=None):
"""
Performs set up for executing the spatial function.
"""
# Does the spatial backend support this?
func = getattr(SpatialBackend, att, False)
if desc is None: desc = att
if not func: raise ImproperlyConfigured('%s stored procedure not available.' % desc)
# 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, aggregate)
return procedure_args, geo_field
def _spatial_aggregate(self, att, field_name=None,
agg_field=None, convert_func=None,
geo_field_type=None, tolerance=0.0005):
"""
DRY routine for calling aggregate spatial stored procedures and
returning their result to the caller of the function.
"""
# Constructing the setup keyword arguments.
setup_kwargs = {'aggregate' : True,
'field_name' : field_name,
'geo_field_type' : geo_field_type,
}
procedure_args, geo_field = self._spatial_setup(att, **setup_kwargs)
if SpatialBackend.oracle:
procedure_args['tolerance'] = tolerance
# Adding in selection SQL for Oracle geometry columns.
if agg_field is GeometryField:
agg_sql = '%s' % SpatialBackend.select
else:
agg_sql = '%s'
agg_sql = agg_sql % ('%(function)s(SDOAGGRTYPE(%(geo_col)s,%(tolerance)s))' % procedure_args)
else:
agg_sql = '%(function)s(%(geo_col)s)' % procedure_args
# Wrapping our selection SQL in `GeomSQL` to bypass quoting, and
# specifying the type of the aggregate field.
self.query.select = [GeomSQL(agg_sql)]
self.query.select_fields = [agg_field]
try:
# `asql` => not overriding `sql` module.
asql, params = self.query.as_sql()
except sql.datastructures.EmptyResultSet:
return None
# Getting a cursor, executing the query, and extracting the returned
# value from the aggregate function.
cursor = connection.cursor()
cursor.execute(asql, params)
result = cursor.fetchone()[0]
# If the `agg_field` is specified as a GeometryField, then autmatically
# set up the conversion function.
if agg_field is GeometryField and not callable(convert_func):
if SpatialBackend.postgis:
def convert_geom(hex, geo_field):
if hex: return SpatialBackend.Geometry(hex)
else: return None
elif SpatialBackend.oracle:
def convert_geom(clob, geo_field):
if clob: return SpatialBackend.Geometry(clob.read(), geo_field._srid)
else: return None
convert_func = convert_geom
# Returning the callback function evaluated on the result culled
# from the executed cursor.
if callable(convert_func):
return convert_func(result, geo_field)
else:
return result
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', [])
# 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)
for k, v in default_args.iteritems(): settings['procedure_args'].setdefault(k, v)
else:
geo_field = settings['geo_field']
# The attribute to attach to the model.
if not isinstance(model_att, basestring): model_att = att
# Special handling for any argument that is a geometry.
for name in settings['geom_args']:
# Using the field's get_db_prep_lookup() to get any needed
# transformation SQL -- we pass in a 'dummy' `contains` lookup.
where, params = geo_field.get_db_prep_lookup('contains', settings['procedure_args'][name])
# Replacing the procedure format with that of any needed
# transformation SQL.
old_fmt = '%%(%s)s' % name
new_fmt = where[0] % '%%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 SpatialBackend.select:
self.query.custom_select[model_att] = SpatialBackend.select
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.
if geo_field.geodetic:
dist_att = 'm'
else:
dist_att = Distance.unit_attname(geo_field._unit_name)
# Shortcut booleans for what distance function we're using.
distance = func == 'distance'
length = func == 'length'
perimeter = func == 'perimeter'
if not (distance or length or perimeter):
raise ValueError('Unknown distance function: %s' % func)
# 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]
# If the spheroid calculation is desired, either by the `spheroid`
# keyword or wehn 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 (SpatialBackend.postgis and geo_field.geodetic and length):
lookup_params.append('spheroid')
where, params = geo_field.get_db_prep_lookup('distance_lte', lookup_params)
# The `geom_args` flag is set to true if a geometry parameter was
# passed in.
geom_args = bool(geom)
if SpatialBackend.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)
geodetic = unit_name in geo_field.geodetic_units
else:
geodetic = geo_field.geodetic
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)' % (SpatialBackend.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.
procedure_fmt += ', %%s'
else:
# We need to transform the geom to the srid specified in `transform()`,
# so wrapping the geometry placeholder in transformation SQL.
procedure_fmt += ', %s(%%%%s, %s)' % (SpatialBackend.transform, self.query.transformed_srid)
else:
# `transform()` was not used on this GeoQuerySet.
procedure_fmt = '%(geo_col)s,%(geom)s'
if 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 isinstance(geo_field, PointField):
raise TypeError('Spherical distance calculation only supported on PointFields.')
if not str(SpatialBackend.Geometry(buffer(params[0].wkb)).geom_type) == 'Point':
raise TypeError('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' : SpatialBackend.distance_spheroid, 'spheroid' : where[1]})
else:
procedure_args.update({'function' : SpatialBackend.distance_sphere})
elif length or perimeter:
procedure_fmt = '%(geo_col)s'
if geodetic and length:
# There's no `length_sphere`
procedure_fmt += ',%(spheroid)s'
procedure_args.update({'function' : SpatialBackend.length_spheroid, 'spheroid' : where[1]})
# 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'] = [SpatialBackend.Adaptor(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 SpatialBackend.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 SpatialBackend.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, aggregate=False):
"""
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.
"""
# If this is an aggregate spatial query, the flag needs to be
# set on the `GeoQuery` object of this queryset.
if aggregate: self.query.aggregate = True
# Is this operation going to be on a related geographic field?
if not geo_field in self.model._meta.fields:
# 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])
self.query.pre_sql_setup()
rel_table, rel_col = self.query.related_select_cols[self.query.related_select_fields.index(geo_field)]
return self.query._field_column(geo_field, rel_table)
else:
return self.query._field_column(geo_field)