95 lines
2.9 KiB
Python
95 lines
2.9 KiB
Python
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from django.contrib.gis.db.models.fields import (
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ExtentField,
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GeometryCollectionField,
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GeometryField,
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LineStringField,
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)
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from django.db.models import Aggregate, Value
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from django.utils.functional import cached_property
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__all__ = ["Collect", "Extent", "Extent3D", "MakeLine", "Union"]
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class GeoAggregate(Aggregate):
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function = None
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is_extent = False
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@cached_property
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def output_field(self):
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return self.output_field_class(self.source_expressions[0].output_field.srid)
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def as_sql(self, compiler, connection, function=None, **extra_context):
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# this will be called again in parent, but it's needed now - before
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# we get the spatial_aggregate_name
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connection.ops.check_expression_support(self)
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return super().as_sql(
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compiler,
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connection,
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function=function or connection.ops.spatial_aggregate_name(self.name),
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**extra_context,
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)
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def as_oracle(self, compiler, connection, **extra_context):
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if not self.is_extent:
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tolerance = self.extra.get("tolerance") or getattr(self, "tolerance", 0.05)
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clone = self.copy()
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clone.set_source_expressions(
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[
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*self.get_source_expressions(),
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Value(tolerance),
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]
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)
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template = "%(function)s(SDOAGGRTYPE(%(expressions)s))"
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return clone.as_sql(
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compiler, connection, template=template, **extra_context
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)
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return self.as_sql(compiler, connection, **extra_context)
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def resolve_expression(
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self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
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):
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c = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
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for expr in c.get_source_expressions():
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if not hasattr(expr.field, "geom_type"):
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raise ValueError(
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"Geospatial aggregates only allowed on geometry fields."
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)
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return c
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class Collect(GeoAggregate):
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name = "Collect"
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output_field_class = GeometryCollectionField
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class Extent(GeoAggregate):
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name = "Extent"
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is_extent = "2D"
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def __init__(self, expression, **extra):
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super().__init__(expression, output_field=ExtentField(), **extra)
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def convert_value(self, value, expression, connection):
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return connection.ops.convert_extent(value)
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class Extent3D(GeoAggregate):
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name = "Extent3D"
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is_extent = "3D"
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def __init__(self, expression, **extra):
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super().__init__(expression, output_field=ExtentField(), **extra)
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def convert_value(self, value, expression, connection):
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return connection.ops.convert_extent3d(value)
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class MakeLine(GeoAggregate):
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name = "MakeLine"
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output_field_class = LineStringField
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class Union(GeoAggregate):
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name = "Union"
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output_field_class = GeometryField
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