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synced 2025-10-24 06:06:09 +00:00
Fixed #24214 -- Added GIS functions to replace geoqueryset's methods
Thanks Simon Charette and Tim Graham for the reviews.
This commit is contained in:
Claude Paroz
@@ -1,3 +1,4 @@
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import re
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from functools import partial
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from django.contrib.gis.db.models import aggregates
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@@ -59,11 +60,11 @@ class BaseSpatialFeatures(object):
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# `has_<name>_method` (defined in __init__) which accesses connection.ops
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# to determine GIS method availability.
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geoqueryset_methods = (
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'area', 'centroid', 'difference', 'distance', 'distance_spheroid',
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'envelope', 'force_rhr', 'geohash', 'gml', 'intersection', 'kml',
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'length', 'num_geom', 'perimeter', 'point_on_surface', 'reverse',
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'scale', 'snap_to_grid', 'svg', 'sym_difference', 'transform',
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'translate', 'union', 'unionagg',
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'area', 'bounding_circle', 'centroid', 'difference', 'distance',
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'distance_spheroid', 'envelope', 'force_rhr', 'geohash', 'gml',
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'intersection', 'kml', 'length', 'mem_size', 'num_geom', 'num_points',
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'perimeter', 'point_on_surface', 'reverse', 'scale', 'snap_to_grid',
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'svg', 'sym_difference', 'transform', 'translate', 'union', 'unionagg',
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)
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# Specifies whether the Collect and Extent aggregates are supported by the database
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@@ -86,5 +87,13 @@ class BaseSpatialFeatures(object):
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setattr(self.__class__, 'has_%s_method' % method,
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property(partial(BaseSpatialFeatures.has_ops_method, method=method)))
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def __getattr__(self, name):
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m = re.match(r'has_(\w*)_function$', name)
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if m:
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func_name = m.group(1)
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if func_name not in self.connection.ops.unsupported_functions:
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return True
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return False
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def has_ops_method(self, method):
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return getattr(self.connection.ops, method, False)
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@@ -22,6 +22,7 @@ class BaseSpatialOperations(object):
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geometry = False
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area = False
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bounding_circle = False
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centroid = False
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difference = False
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distance = False
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@@ -30,7 +31,6 @@ class BaseSpatialOperations(object):
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envelope = False
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force_rhr = False
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mem_size = False
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bounding_circle = False
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num_geom = False
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num_points = False
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perimeter = False
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@@ -48,6 +48,22 @@ class BaseSpatialOperations(object):
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# Aggregates
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disallowed_aggregates = ()
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geom_func_prefix = ''
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# Mapping between Django function names and backend names, when names do not
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# match; used in spatial_function_name().
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function_names = {}
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# Blacklist/set of known unsupported functions of the backend
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unsupported_functions = {
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'Area', 'AsGeoHash', 'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG',
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'BoundingCircle', 'Centroid', 'Difference', 'Distance', 'Envelope',
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'ForceRHR', 'Intersection', 'Length', 'MemSize', 'NumGeometries',
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'NumPoints', 'Perimeter', 'PointOnSurface', 'Reverse', 'Scale',
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'SnapToGrid', 'SymDifference', 'Transform', 'Translate',
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'Union',
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}
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# Serialization
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geohash = False
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geojson = False
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@@ -108,9 +124,14 @@ class BaseSpatialOperations(object):
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def spatial_aggregate_name(self, agg_name):
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raise NotImplementedError('Aggregate support not implemented for this spatial backend.')
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def spatial_function_name(self, func_name):
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if func_name in self.unsupported_functions:
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raise NotImplementedError("This backend doesn't support the %s function." % func_name)
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return self.function_names.get(func_name, self.geom_func_prefix + func_name)
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# Routines for getting the OGC-compliant models.
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def geometry_columns(self):
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raise NotImplementedError('subclasses of BaseSpatialOperations must a provide geometry_columns() method')
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raise NotImplementedError('Subclasses of BaseSpatialOperations must provide a geometry_columns() method.')
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def spatial_ref_sys(self):
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raise NotImplementedError('subclasses of BaseSpatialOperations must a provide spatial_ref_sys() method')
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@@ -8,12 +8,13 @@ from psycopg2.extensions import ISQLQuote
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class PostGISAdapter(object):
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def __init__(self, geom):
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def __init__(self, geom, geography=False):
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"Initializes on the geometry."
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# Getting the WKB (in string form, to allow easy pickling of
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# the adaptor) and the SRID from the geometry.
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self.ewkb = bytes(geom.ewkb)
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self.srid = geom.srid
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self.geography = geography
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self._adapter = Binary(self.ewkb)
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def __conform__(self, proto):
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@@ -44,4 +45,7 @@ class PostGISAdapter(object):
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def getquoted(self):
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"Returns a properly quoted string for use in PostgreSQL/PostGIS."
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# psycopg will figure out whether to use E'\\000' or '\000'
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return str('ST_GeomFromEWKB(%s)' % self._adapter.getquoted().decode())
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return str('%s(%s)' % (
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'ST_GeogFromWKB' if self.geography else 'ST_GeomFromEWKB',
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self._adapter.getquoted().decode())
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)
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@@ -88,6 +88,13 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
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'distance_lte': PostGISDistanceOperator(func='ST_Distance', op='<=', geography=True),
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}
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unsupported_functions = set()
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function_names = {
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'BoundingCircle': 'ST_MinimumBoundingCircle',
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'MemSize': 'ST_Mem_Size',
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'NumPoints': 'ST_NPoints',
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}
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def __init__(self, connection):
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super(PostGISOperations, self).__init__(connection)
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351
django/contrib/gis/db/models/functions.py
Normal file
351
django/contrib/gis/db/models/functions.py
Normal file
@@ -0,0 +1,351 @@
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from decimal import Decimal
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from django.contrib.gis.db.models.fields import GeometryField
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from django.contrib.gis.db.models.sql import AreaField
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from django.contrib.gis.geos.geometry import GEOSGeometry
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from django.contrib.gis.measure import (
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Area as AreaMeasure, Distance as DistanceMeasure,
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)
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from django.core.exceptions import FieldError
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from django.db.models import FloatField, IntegerField, TextField
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from django.db.models.expressions import Func, Value
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from django.utils import six
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NUMERIC_TYPES = six.integer_types + (float, Decimal)
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class GeoFunc(Func):
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function = None
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output_field_class = None
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geom_param_pos = 0
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def __init__(self, *expressions, **extra):
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if 'output_field' not in extra and self.output_field_class:
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extra['output_field'] = self.output_field_class()
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super(GeoFunc, self).__init__(*expressions, **extra)
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@property
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def name(self):
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return self.__class__.__name__
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@property
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def srid(self):
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expr = self.source_expressions[self.geom_param_pos]
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if hasattr(expr, 'srid'):
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return expr.srid
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try:
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return expr.field.srid
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except (AttributeError, FieldError):
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return None
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def as_sql(self, compiler, connection):
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if self.function is None:
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self.function = connection.ops.spatial_function_name(self.name)
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return super(GeoFunc, self).as_sql(compiler, connection)
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def resolve_expression(self, *args, **kwargs):
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res = super(GeoFunc, self).resolve_expression(*args, **kwargs)
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base_srid = res.srid
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if not base_srid:
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raise TypeError("Geometry functions can only operate on geometric content.")
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for pos, expr in enumerate(res.source_expressions[1:], start=1):
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if isinstance(expr, GeomValue) and expr.srid != base_srid:
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# Automatic SRID conversion so objects are comparable
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res.source_expressions[pos] = Transform(expr, base_srid).resolve_expression(*args, **kwargs)
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return res
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def _handle_param(self, value, param_name='', check_types=None):
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if not hasattr(value, 'resolve_expression'):
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if check_types and not isinstance(value, check_types):
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raise TypeError(
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"The %s parameter has the wrong type: should be %s." % (
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param_name, str(check_types))
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)
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return value
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class GeomValue(Value):
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geography = False
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@property
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def srid(self):
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return self.value.srid
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def as_sql(self, compiler, connection):
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if self.geography:
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self.value = connection.ops.Adapter(self.value, geography=self.geography)
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else:
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self.value = connection.ops.Adapter(self.value)
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return super(GeomValue, self).as_sql(compiler, connection)
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class GeoFuncWithGeoParam(GeoFunc):
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def __init__(self, expression, geom, *expressions, **extra):
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if not hasattr(geom, 'srid'):
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# Try to interpret it as a geometry input
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try:
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geom = GEOSGeometry(geom)
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except Exception:
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raise ValueError("This function requires a geometric parameter.")
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if not geom.srid:
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raise ValueError("Please provide a geometry attribute with a defined SRID.")
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geom = GeomValue(geom)
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super(GeoFuncWithGeoParam, self).__init__(expression, geom, *expressions, **extra)
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class Area(GeoFunc):
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def as_sql(self, compiler, connection):
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if connection.ops.oracle:
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self.output_field = AreaField('sq_m') # Oracle returns area in units of meters.
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else:
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if connection.ops.geography:
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# Geography fields support area calculation, returns square meters.
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self.output_field = AreaField('sq_m')
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elif not self.output_field.geodetic(connection):
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# Getting the area units of the geographic field.
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self.output_field = AreaField(
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AreaMeasure.unit_attname(self.output_field.units_name(connection)))
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else:
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# TODO: Do we want to support raw number areas for geodetic fields?
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raise NotImplementedError('Area on geodetic coordinate systems not supported.')
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return super(Area, self).as_sql(compiler, connection)
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class AsGeoJSON(GeoFunc):
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output_field_class = TextField
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def __init__(self, expression, bbox=False, crs=False, precision=8, **extra):
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expressions = [expression]
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if precision is not None:
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expressions.append(self._handle_param(precision, 'precision', six.integer_types))
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options = 0
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if crs and bbox:
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options = 3
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elif bbox:
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options = 1
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elif crs:
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options = 2
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if options:
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expressions.append(options)
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super(AsGeoJSON, self).__init__(*expressions, **extra)
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class AsGML(GeoFunc):
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geom_param_pos = 1
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output_field_class = TextField
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def __init__(self, expression, version=2, precision=8, **extra):
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expressions = [version, expression]
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if precision is not None:
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expressions.append(self._handle_param(precision, 'precision', six.integer_types))
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super(AsGML, self).__init__(*expressions, **extra)
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class AsKML(AsGML):
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pass
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class AsSVG(GeoFunc):
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output_field_class = TextField
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def __init__(self, expression, relative=False, precision=8, **extra):
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relative = relative if hasattr(relative, 'resolve_expression') else int(relative)
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expressions = [
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expression,
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relative,
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self._handle_param(precision, 'precision', six.integer_types),
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]
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super(AsSVG, self).__init__(*expressions, **extra)
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class BoundingCircle(GeoFunc):
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def __init__(self, expression, num_seg=48, **extra):
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super(BoundingCircle, self).__init__(*[expression, num_seg], **extra)
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class Centroid(GeoFunc):
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pass
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class Difference(GeoFuncWithGeoParam):
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pass
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class DistanceResultMixin(object):
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def convert_value(self, value, expression, connection, context):
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if value is None:
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return None
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geo_field = GeometryField(srid=self.srid) # Fake field to get SRID info
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if geo_field.geodetic(connection):
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dist_att = 'm'
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else:
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dist_att = DistanceMeasure.unit_attname(geo_field.units_name(connection))
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return DistanceMeasure(**{dist_att: value})
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class Distance(DistanceResultMixin, GeoFuncWithGeoParam):
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output_field_class = FloatField
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spheroid = None
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def __init__(self, expr1, expr2, spheroid=None, **extra):
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expressions = [expr1, expr2]
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if spheroid is not None:
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self.spheroid = spheroid
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expressions += (self._handle_param(spheroid, 'spheroid', bool),)
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super(Distance, self).__init__(*expressions, **extra)
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def as_postgresql(self, compiler, connection):
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geo_field = GeometryField(srid=self.srid) # Fake field to get SRID info
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src_field = self.get_source_fields()[0]
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geography = src_field.geography and self.srid == 4326
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if geography:
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# Set parameters as geography if base field is geography
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for pos, expr in enumerate(
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self.source_expressions[self.geom_param_pos + 1:], start=self.geom_param_pos + 1):
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if isinstance(expr, GeomValue):
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expr.geography = True
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elif geo_field.geodetic(connection):
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# Geometry fields with geodetic (lon/lat) coordinates need special distance functions
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if self.spheroid:
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self.function = 'ST_Distance_Spheroid' # More accurate, resource intensive
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# Replace boolean param by the real spheroid of the base field
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self.source_expressions[2] = Value(geo_field._spheroid)
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else:
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self.function = 'ST_Distance_Sphere'
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return super(Distance, self).as_sql(compiler, connection)
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class Envelope(GeoFunc):
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pass
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class ForceRHR(GeoFunc):
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pass
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class GeoHash(GeoFunc):
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output_field_class = TextField
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def __init__(self, expression, precision=None, **extra):
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expressions = [expression]
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if precision is not None:
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expressions.append(self._handle_param(precision, 'precision', six.integer_types))
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super(GeoHash, self).__init__(*expressions, **extra)
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class Intersection(GeoFuncWithGeoParam):
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pass
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class Length(DistanceResultMixin, GeoFunc):
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output_field_class = FloatField
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def __init__(self, expr1, spheroid=True, **extra):
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self.spheroid = spheroid
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super(Length, self).__init__(expr1, **extra)
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def as_postgresql(self, compiler, connection):
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geo_field = GeometryField(srid=self.srid) # Fake field to get SRID info
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src_field = self.get_source_fields()[0]
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geography = src_field.geography and self.srid == 4326
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if geography:
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self.source_expressions.append(Value(self.spheroid))
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elif geo_field.geodetic(connection):
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# Geometry fields with geodetic (lon/lat) coordinates need length_spheroid
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self.function = 'ST_Length_Spheroid'
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self.source_expressions.append(Value(geo_field._spheroid))
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else:
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dim = min(f.dim for f in self.get_source_fields() if f)
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if dim > 2:
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self.function = connection.ops.length3d
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return super(Length, self).as_sql(compiler, connection)
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class MemSize(GeoFunc):
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output_field_class = IntegerField
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class NumGeometries(GeoFunc):
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output_field_class = IntegerField
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class NumPoints(GeoFunc):
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output_field_class = IntegerField
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class Perimeter(DistanceResultMixin, GeoFunc):
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output_field_class = FloatField
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def as_postgresql(self, compiler, connection):
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dim = min(f.dim for f in self.get_source_fields())
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if dim > 2:
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self.function = connection.ops.perimeter3d
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return super(Perimeter, self).as_sql(compiler, connection)
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class PointOnSurface(GeoFunc):
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pass
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class Reverse(GeoFunc):
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pass
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class Scale(GeoFunc):
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def __init__(self, expression, x, y, z=0.0, **extra):
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expressions = [
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expression,
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self._handle_param(x, 'x', NUMERIC_TYPES),
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self._handle_param(y, 'y', NUMERIC_TYPES),
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]
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if z != 0.0:
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expressions.append(self._handle_param(z, 'z', NUMERIC_TYPES))
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super(Scale, self).__init__(*expressions, **extra)
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class SnapToGrid(GeoFunc):
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def __init__(self, expression, *args, **extra):
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nargs = len(args)
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expressions = [expression]
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||||
if nargs in (1, 2):
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||||
expressions.extend(
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||||
[self._handle_param(arg, '', NUMERIC_TYPES) for arg in args]
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)
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elif nargs == 4:
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# Reverse origin and size param ordering
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expressions.extend(
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||||
[self._handle_param(arg, '', NUMERIC_TYPES) for arg in args[2:]]
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||||
)
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expressions.extend(
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||||
[self._handle_param(arg, '', NUMERIC_TYPES) for arg in args[0:2]]
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||||
)
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else:
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raise ValueError('Must provide 1, 2, or 4 arguments to `SnapToGrid`.')
|
||||
super(SnapToGrid, self).__init__(*expressions, **extra)
|
||||
|
||||
|
||||
class SymDifference(GeoFuncWithGeoParam):
|
||||
pass
|
||||
|
||||
|
||||
class Transform(GeoFunc):
|
||||
def __init__(self, expression, srid, **extra):
|
||||
expressions = [
|
||||
expression,
|
||||
self._handle_param(srid, 'srid', six.integer_types),
|
||||
]
|
||||
super(Transform, self).__init__(*expressions, **extra)
|
||||
|
||||
@property
|
||||
def srid(self):
|
||||
# Make srid the resulting srid of the transformation
|
||||
return self.source_expressions[self.geom_param_pos + 1].value
|
||||
|
||||
|
||||
class Translate(Scale):
|
||||
pass
|
||||
|
||||
|
||||
class Union(GeoFuncWithGeoParam):
|
||||
pass
|
||||
Reference in New Issue
Block a user