Source code for django.contrib.gis.forms.fields

from django import forms
from django.contrib.gis.gdal import GDALException
from django.contrib.gis.geos import GEOSException, GEOSGeometry
from django.core.exceptions import ValidationError
from django.utils.translation import gettext_lazy as _

from .widgets import OpenLayersWidget

[docs]class GeometryField(forms.Field): """ This is the basic form field for a Geometry. Any textual input that is accepted by GEOSGeometry is accepted by this form. By default, this includes WKT, HEXEWKB, WKB (in a buffer), and GeoJSON. """ widget = OpenLayersWidget geom_type = 'GEOMETRY' default_error_messages = { 'required': _('No geometry value provided.'), 'invalid_geom': _('Invalid geometry value.'), 'invalid_geom_type': _('Invalid geometry type.'), 'transform_error': _('An error occurred when transforming the geometry ' 'to the SRID of the geometry form field.'), } def __init__(self, *, srid=None, geom_type=None, **kwargs): self.srid = srid if geom_type is not None: self.geom_type = geom_type super().__init__(**kwargs) self.widget.attrs['geom_type'] = self.geom_type def to_python(self, value): """Transform the value to a Geometry object.""" if value in self.empty_values: return None if not isinstance(value, GEOSGeometry): if hasattr(self.widget, 'deserialize'): try: value = self.widget.deserialize(value) except GDALException: value = None else: try: value = GEOSGeometry(value) except (GEOSException, ValueError, TypeError): value = None if value is None: raise ValidationError(self.error_messages['invalid_geom'], code='invalid_geom') # Try to set the srid if not value.srid: try: value.srid = self.widget.map_srid except AttributeError: if self.srid: value.srid = self.srid return value def clean(self, value): """ Validate that the input value can be converted to a Geometry object and return it. Raise a ValidationError if the value cannot be instantiated as a Geometry. """ geom = super().clean(value) if geom is None: return geom # Ensuring that the geometry is of the correct type (indicated # using the OGC string label). if str(geom.geom_type).upper() != self.geom_type and not self.geom_type == 'GEOMETRY': raise ValidationError(self.error_messages['invalid_geom_type'], code='invalid_geom_type') # Transforming the geometry if the SRID was set. if self.srid and self.srid != -1 and self.srid != geom.srid: try: geom.transform(self.srid) except GEOSException: raise ValidationError( self.error_messages['transform_error'], code='transform_error') return geom def has_changed(self, initial, data): """ Compare geographic value of data with its initial value. """ try: data = self.to_python(data) initial = self.to_python(initial) except ValidationError: return True # Only do a geographic comparison if both values are available if initial and data: data.transform(initial.srid) # If the initial value was not added by the browser, the geometry # provided may be slightly different, the first time it is saved. # The comparison is done with a very low tolerance. return not initial.equals_exact(data, tolerance=0.000001) else: # Check for change of state of existence return bool(initial) != bool(data)
[docs]class GeometryCollectionField(GeometryField): geom_type = 'GEOMETRYCOLLECTION'
[docs]class PointField(GeometryField): geom_type = 'POINT'
[docs]class MultiPointField(GeometryField): geom_type = 'MULTIPOINT'
[docs]class LineStringField(GeometryField): geom_type = 'LINESTRING'
[docs]class MultiLineStringField(GeometryField): geom_type = 'MULTILINESTRING'
[docs]class PolygonField(GeometryField): geom_type = 'POLYGON'
[docs]class MultiPolygonField(GeometryField): geom_type = 'MULTIPOLYGON'
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