django1/django/contrib/gis/forms/widgets.py

116 lines
3.4 KiB
Python

from __future__ import unicode_literals
import logging
from django.conf import settings
from django.contrib.gis import gdal
from django.contrib.gis.geos import GEOSException, GEOSGeometry
from django.forms.widgets import Widget
from django.template import loader
from django.utils import six, translation
logger = logging.getLogger('django.contrib.gis')
class BaseGeometryWidget(Widget):
"""
The base class for rich geometry widgets.
Renders a map using the WKT of the geometry.
"""
geom_type = 'GEOMETRY'
map_srid = 4326
map_width = 600
map_height = 400
display_raw = False
supports_3d = False
template_name = '' # set on subclasses
def __init__(self, attrs=None):
self.attrs = {}
for key in ('geom_type', 'map_srid', 'map_width', 'map_height', 'display_raw'):
self.attrs[key] = getattr(self, key)
if attrs:
self.attrs.update(attrs)
def serialize(self, value):
return value.wkt if value else ''
def deserialize(self, value):
try:
return GEOSGeometry(value, self.map_srid)
except (GEOSException, ValueError) as err:
logger.error("Error creating geometry from value '%s' (%s)", value, err)
return None
def render(self, name, value, attrs=None):
# If a string reaches here (via a validation error on another
# field) then just reconstruct the Geometry.
if isinstance(value, six.string_types):
value = self.deserialize(value)
if value:
# Check that srid of value and map match
if value.srid != self.map_srid:
try:
ogr = value.ogr
ogr.transform(self.map_srid)
value = ogr
except gdal.GDALException as err:
logger.error(
"Error transforming geometry from srid '%s' to srid '%s' (%s)",
value.srid, self.map_srid, err
)
context = self.build_attrs(
attrs,
name=name,
module='geodjango_%s' % name.replace('-', '_'), # JS-safe
serialized=self.serialize(value),
geom_type=gdal.OGRGeomType(self.attrs['geom_type']),
STATIC_URL=settings.STATIC_URL,
LANGUAGE_BIDI=translation.get_language_bidi(),
)
return loader.render_to_string(self.template_name, context)
class OpenLayersWidget(BaseGeometryWidget):
template_name = 'gis/openlayers.html'
class Media:
js = (
'http://openlayers.org/api/2.13.1/OpenLayers.js',
'gis/js/OLMapWidget.js',
)
class OSMWidget(BaseGeometryWidget):
"""
An OpenLayers/OpenStreetMap-based widget.
"""
template_name = 'gis/openlayers-osm.html'
default_lon = 5
default_lat = 47
class Media:
js = (
'http://openlayers.org/api/2.13.1/OpenLayers.js',
'gis/js/OLMapWidget.js',
)
def __init__(self, attrs=None):
super(OSMWidget, self).__init__()
for key in ('default_lon', 'default_lat'):
self.attrs[key] = getattr(self, key)
if attrs:
self.attrs.update(attrs)
@property
def map_srid(self):
# Use the official spherical mercator projection SRID when GDAL is
# available; otherwise, fallback to 900913.
if gdal.HAS_GDAL:
return 3857
else:
return 900913