from django.db import connections from django.db.models.query import QuerySet, ValuesQuerySet, ValuesListQuerySet 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 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' % (kwargs.keys(),)) 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+ supports GeoJSON serialization.') if not isinstance(precision, (int, long)): raise TypeError('Precision keyword must be set with an integer.') # Setting the options flag -- which depends on which version of # PostGIS we're using. 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, int, long)) 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, (int, long)): 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, (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)' % (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 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_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(buffer(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