|
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576 |
- from django.contrib.gis.db.models.fields import (
- ExtentField, GeometryCollectionField, GeometryField, LineStringField,
- )
- from django.db.models.aggregates import Aggregate
- from django.utils.functional import cached_property
-
- __all__ = ['Collect', 'Extent', 'Extent3D', 'MakeLine', 'Union']
-
-
- class GeoAggregate(Aggregate):
- function = None
- is_extent = False
-
- @cached_property
- def output_field(self):
- return self.output_field_class(self.source_expressions[0].output_field.srid)
-
- def as_sql(self, compiler, connection, function=None, **extra_context):
- # this will be called again in parent, but it's needed now - before
- # we get the spatial_aggregate_name
- connection.ops.check_expression_support(self)
- return super().as_sql(
- compiler,
- connection,
- function=function or connection.ops.spatial_aggregate_name(self.name),
- **extra_context
- )
-
- def as_oracle(self, compiler, connection, **extra_context):
- tolerance = self.extra.get('tolerance') or getattr(self, 'tolerance', 0.05)
- template = None if self.is_extent else '%(function)s(SDOAGGRTYPE(%(expressions)s,%(tolerance)s))'
- return self.as_sql(compiler, connection, template=template, tolerance=tolerance, **extra_context)
-
- def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
- c = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
- for expr in c.get_source_expressions():
- if not hasattr(expr.field, 'geom_type'):
- raise ValueError('Geospatial aggregates only allowed on geometry fields.')
- return c
-
-
- class Collect(GeoAggregate):
- name = 'Collect'
- output_field_class = GeometryCollectionField
-
-
- class Extent(GeoAggregate):
- name = 'Extent'
- is_extent = '2D'
-
- def __init__(self, expression, **extra):
- super().__init__(expression, output_field=ExtentField(), **extra)
-
- def convert_value(self, value, expression, connection):
- return connection.ops.convert_extent(value)
-
-
- class Extent3D(GeoAggregate):
- name = 'Extent3D'
- is_extent = '3D'
-
- def __init__(self, expression, **extra):
- super().__init__(expression, output_field=ExtentField(), **extra)
-
- def convert_value(self, value, expression, connection):
- return connection.ops.convert_extent3d(value)
-
-
- class MakeLine(GeoAggregate):
- name = 'MakeLine'
- output_field_class = LineStringField
-
-
- class Union(GeoAggregate):
- name = 'Union'
- output_field_class = GeometryField
|