85 lines
2.9 KiB
Python
85 lines
2.9 KiB
Python
"""
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The GeometryColumns and SpatialRefSys models for the SpatiaLite backend.
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"""
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from django.contrib.gis.db.backends.base.models import SpatialRefSysMixin
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from django.contrib.gis.db.backends.spatialite.base import DatabaseWrapper
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from django.db import connection, models
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from django.db.backends.signals import connection_created
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from django.utils.encoding import python_2_unicode_compatible
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@python_2_unicode_compatible
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class SpatialiteGeometryColumns(models.Model):
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"""
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The 'geometry_columns' table from SpatiaLite.
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"""
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f_table_name = models.CharField(max_length=256)
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f_geometry_column = models.CharField(max_length=256)
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coord_dimension = models.IntegerField()
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srid = models.IntegerField(primary_key=True)
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spatial_index_enabled = models.IntegerField()
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class Meta:
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app_label = 'gis'
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db_table = 'geometry_columns'
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managed = False
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@classmethod
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def table_name_col(cls):
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"""
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Returns the name of the metadata column used to store the feature table
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name.
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"""
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return 'f_table_name'
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@classmethod
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def geom_col_name(cls):
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"""
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Returns the name of the metadata column used to store the feature
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geometry column.
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"""
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return 'f_geometry_column'
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def __str__(self):
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return "%s.%s - %dD %s field (SRID: %d)" % \
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(self.f_table_name, self.f_geometry_column,
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self.coord_dimension, self.type, self.srid)
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class SpatialiteSpatialRefSys(models.Model, SpatialRefSysMixin):
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"""
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The 'spatial_ref_sys' table from SpatiaLite.
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"""
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srid = models.IntegerField(primary_key=True)
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auth_name = models.CharField(max_length=256)
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auth_srid = models.IntegerField()
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ref_sys_name = models.CharField(max_length=256)
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proj4text = models.CharField(max_length=2048)
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@property
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def wkt(self):
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if hasattr(self, 'srtext'):
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return self.srtext
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from django.contrib.gis.gdal import SpatialReference
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return SpatialReference(self.proj4text).wkt
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class Meta:
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app_label = 'gis'
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db_table = 'spatial_ref_sys'
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managed = False
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def add_spatial_version_related_fields(sender, **kwargs):
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"""
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Adds fields after establishing a database connection to prevent database
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operations at compile time.
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"""
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if connection_created.disconnect(add_spatial_version_related_fields, sender=DatabaseWrapper):
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spatial_version = connection.ops.spatial_version[0]
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if spatial_version >= 4:
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SpatialiteSpatialRefSys.add_to_class('srtext', models.CharField(max_length=2048))
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SpatialiteGeometryColumns.add_to_class('type', models.IntegerField(db_column='geometry_type'))
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else:
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SpatialiteGeometryColumns.add_to_class('type', models.CharField(max_length=30))
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connection_created.connect(add_spatial_version_related_fields, sender=DatabaseWrapper)
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