def geojson(self, srid):
import json
from madrona.common.jsonutils import get_properties_json, get_feature_json
props = get_properties_json(self)
props.pop('output_geom')
json_geom = self.output_geom.transform(srid, clone=True).json
return get_feature_json(json_geom, json.dumps(props))
def get_leaseblock_features(request):
from madrona.common.jsonutils import get_properties_json, get_feature_json, srid_to_urn, srid_to_proj
srid = settings.GEOJSON_SRID
leaseblock_ids = request.GET.getlist('leaseblock_ids[]')
leaseblocks = LeaseBlock.objects.filter(prot_numb__in=leaseblock_ids)
feature_jsons = []
for leaseblock in leaseblocks:
try:
geom = leaseblock.geometry.transform(srid, clone=True).json
except:
srid = settings.GEOJSON_SRID_BACKUP
geom = leaseblock.geometry.transform(srid, clone=True).json
feature_jsons.append(get_feature_json(geom, json.dumps('')))#json.dumps(props)))
#feature_jsons.append(leaseblock.geometry.transform(srid, clone=True).json)
'''
geojson = """{
"type": "Feature",
"geometry": %s,
"properties": {}
}""" %leaseblock.geometry.transform(settings.GEOJSON_SRID, clone=True).json
'''
#json.append({'type': "Feature", 'geometry': leaseblock.geometry.geojson, 'properties': {}})
#return HttpResponse(dumps(json[0]))
geojson = """{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": {"name": "%s"}},
"features": [
%s
]
}""" % (srid_to_urn(srid), ', \n'.join(feature_jsons),)
return HttpResponse(geojson)
def get_leaseblock_features(request):
from madrona.common.jsonutils import get_properties_json, get_feature_json, srid_to_urn, srid_to_proj
srid = settings.GEOJSON_SRID
leaseblock_ids = request.GET.getlist('leaseblock_ids[]')
leaseblocks = LeaseBlock.objects.filter(prot_numb__in=leaseblock_ids)
feature_jsons = []
for leaseblock in leaseblocks:
try:
geom = leaseblock.geometry.transform(srid, clone=True).json
except:
srid = settings.GEOJSON_SRID_BACKUP
geom = leaseblock.geometry.transform(srid, clone=True).json
feature_jsons.append(get_feature_json(
geom, json.dumps(''))) #json.dumps(props)))
#feature_jsons.append(leaseblock.geometry.transform(srid, clone=True).json)
'''
geojson = """{
"type": "Feature",
"geometry": %s,
"properties": {}
}""" %leaseblock.geometry.transform(settings.GEOJSON_SRID, clone=True).json
'''
#json.append({'type': "Feature", 'geometry': leaseblock.geometry.geojson, 'properties': {}})
#return HttpResponse(dumps(json[0]))
geojson = """{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": {"name": "%s"}},
"features": [
%s
]
}""" % (
srid_to_urn(srid),
', \n'.join(feature_jsons),
)
return HttpResponse(geojson)
def geojson(self, srid):
props = get_properties_json(self)
props['absolute_url'] = self.get_absolute_url()
json_geom = self.geometry_dissolved.transform(srid, clone=True).json
return get_feature_json(json_geom, json.dumps(props))
def geojson_link(request, instances):
"""
Generic view for GeoJSON representation of feature classes.
Can be overridden but this is provided a default.
To override, feature class needs a geojson object that returns
a geojson feature string (no trailing comma)::
{ "type": "Feature",
"geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
"properties": {"prop0": "value0"}
}
GeoJSON Feature collections *cannot* be nested within other feature collections
http://lists.geojson.org/pipermail/geojson-geojson.org/2008-October/000464.html
Thus collections can be treated using one of the following strategies:
``flat``: (DEFAULT) The collection is "flattened" to contain all the
features in a single featurecollection (lossy)
``nest_feature_set``: the collection is represented as an empty geometry with a special
feature_set property; a list of UIDs to fetch
(requires a client with knowledge of this convention)
Pass by URL GET parameter like ?strategy=nest_feature_set
"""
from madrona.common import default_mimetypes as mimetypes
from madrona.common.jsonutils import get_properties_json, get_feature_json, srid_to_urn, srid_to_proj
from madrona.features.models import FeatureCollection, SpatialFeature, Feature
from django.contrib.gis.gdal import DataSource
import tempfile
import os
import json
strategy = request.GET.get('strategy', default='flat')
strategy = strategy.lower()
if settings.GEOJSON_SRID:
srid_setting = settings.GEOJSON_SRID
else:
srid_setting = settings.GEOMETRY_DB_SRID
srid = int(request.GET.get('srid', default=srid_setting))
if srid <= 32766: # assumed max EPSG code
crs = srid_to_urn(srid)
else:
crs = srid_to_proj(srid)
if settings.GEOJSON_DOWNLOAD:
download = 'noattach' not in request.GET
else:
download = 'attach' in request.GET
feature_jsons = []
for i in instances:
gj = None
try:
gj = i.geojson(srid)
except AttributeError:
pass
if gj is None:
props = get_properties_json(i)
if issubclass(i.__class__, FeatureCollection):
if strategy == 'nest_feature_set':
# collections are treated as null geoms with 'feature_set' property
props['feature_set'] = [x.uid for x in i.feature_set()]
gj = get_feature_json('null', json.dumps(props))
else: # assume 'flat' strategy and recurse
feats = [f for f in i.feature_set(recurse=True)
if not isinstance(f, FeatureCollection)]
gjs = []
for f in feats:
try:
geom = x.geometry_final.transform(srid, clone=True).json
except:
geom = 'null'
props = get_properties_json(f)
gjs.append(get_feature_json(geom, json.dumps(props)))
gj = ', \n'.join(gjs)
else:
try:
# Eventually support an Option to configure the geometry field?
geom = i.geometry_final.transform(srid, clone=True).json
except:
geom = 'null'
gj = get_feature_json(geom, json.dumps(props))
if gj is not None:
feature_jsons.append(gj)
geojson = """{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": {"name": "%s"}},
"features": [
%s
]
}""" % (crs, ', \n'.join(feature_jsons),)
##### Not reliable, extent call throws unknown OGR error, even with valid datasource
#tmpfile = tempfile.mktemp() + ".json"
#with open(tmpfile, 'w') as fh:
# fh.write(geojson)
#ds = DataSource(tmpfile)
#bbox = list(ds[0].extent.tuple)
#if bbox and len(bbox) == 4:
# # requires "bbox": null, in the geojson
# geojson.replace('"bbox": null,', '"bbox": %s,' % str(bbox))
#del ds
#os.remove(tmpfile)
response = HttpResponse()
response['Content-Type'] = mimetypes.JSON
if download:
filename = '_'.join([slugify(i.name) for i in instances])[:40]
response['Content-Disposition'] = 'attachment; filename=%s.geojson' % filename
response.write(geojson)
return response
def geojson(self, srid):
props = get_properties_json(self)
props['absolute_url'] = self.get_absolute_url()
json_geom = self.geometry_actual.transform(srid, clone=True).json
return get_feature_json(json_geom, json.dumps(props))
def geojson_link(request, instances):
"""
Generic view for GeoJSON representation of feature classes.
Can be overridden but this is provided a default.
To override, feature class needs a geojson object that returns
a geojson feature string (no trailing comma)::
{ "type": "Feature",
"geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
"properties": {"prop0": "value0"}
}
GeoJSON Feature collections *cannot* be nested within other feature collections
http://lists.geojson.org/pipermail/geojson-geojson.org/2008-October/000464.html
Thus collections can be treated using one of the following strategies:
``flat``: (DEFAULT) The collection is "flattened" to contain all the
features in a single featurecollection (lossy)
``nest_feature_set``: the collection is represented as an empty geometry with a special
feature_set property; a list of UIDs to fetch
(requires a client with knowledge of this convention)
Pass by URL GET parameter like ?strategy=nest_feature_set
"""
from madrona.common import default_mimetypes as mimetypes
from madrona.common.jsonutils import get_properties_json, get_feature_json, srid_to_urn, srid_to_proj
from madrona.features.models import FeatureCollection, SpatialFeature, Feature
from django.contrib.gis.gdal import DataSource
import tempfile
import os
import json
strategy = request.GET.get('strategy', default='flat')
strategy = strategy.lower()
if settings.GEOJSON_SRID:
srid_setting = settings.GEOJSON_SRID
else:
srid_setting = settings.GEOMETRY_DB_SRID
srid = int(request.GET.get('srid', default=srid_setting))
if srid <= 32766: # assumed max EPSG code
crs = srid_to_urn(srid)
else:
crs = srid_to_proj(srid)
if settings.GEOJSON_DOWNLOAD:
download = 'noattach' not in request.GET
else:
download = 'attach' in request.GET
feature_jsons = []
for i in instances:
gj = None
try:
gj = i.geojson(srid)
except AttributeError:
pass
if gj is None:
props = get_properties_json(i)
if issubclass(i.__class__, FeatureCollection):
if strategy == 'nest_feature_set':
# collections are treated as null geoms with 'feature_set' property
props['feature_set'] = [x.uid for x in i.feature_set()]
gj = get_feature_json('null', json.dumps(props))
else: # assume 'flat' strategy and recurse
feats = [
f for f in i.feature_set(recurse=True)
if not isinstance(f, FeatureCollection)
]
gjs = []
for f in feats:
try:
geom = x.geometry_final.transform(srid,
clone=True).json
except:
geom = 'null'
props = get_properties_json(f)
gjs.append(get_feature_json(geom, json.dumps(props)))
gj = ', \n'.join(gjs)
else:
try:
# Eventually support an Option to configure the geometry field?
geom = i.geometry_final.transform(srid, clone=True).json
except:
geom = 'null'
gj = get_feature_json(geom, json.dumps(props))
if gj is not None:
feature_jsons.append(gj)
geojson = """{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": {"name": "%s"}},
"features": [
%s
]
}""" % (
crs,
', \n'.join(feature_jsons),
)
##### Not reliable, extent call throws unknown OGR error, even with valid datasource
#tmpfile = tempfile.mktemp() + ".json"
#with open(tmpfile, 'w') as fh:
# fh.write(geojson)
#ds = DataSource(tmpfile)
#bbox = list(ds[0].extent.tuple)
#if bbox and len(bbox) == 4:
# # requires "bbox": null, in the geojson
# geojson.replace('"bbox": null,', '"bbox": %s,' % str(bbox))
#del ds
#os.remove(tmpfile)
response = HttpResponse()
response['Content-Type'] = mimetypes.JSON
if download:
filename = '_'.join([slugify(i.name) for i in instances])[:40]
response[
'Content-Disposition'] = 'attachment; filename=%s.geojson' % filename
response.write(geojson)
return response