#49 Parcels and Districts

* refactors WFS fetching to proper POST handling
* adds authentication support to WFS handling
* reduces dummy geometry for tests to a small area to reduce test network traffic overhead
This commit is contained in:
mpeltriaux 2022-01-04 13:03:21 +01:00
parent 440a4b04d5
commit 62030c4dcc
4 changed files with 124 additions and 48 deletions

View File

@ -80,3 +80,8 @@ LANIS_ZOOM_LUT = {
1000: 30,
500: 31,
}
# Parcel WFS settings
PARCEL_WFS_BASE_URL = "https://www.geoportal.rlp.de/registry/wfs/519"
PARCEL_WFS_USER = "ksp"
PARCEL_WFS_PW = "CHANGE_ME"

View File

@ -8,8 +8,9 @@ Created on: 15.12.21
from django.contrib.gis.db.models.functions import Translate
from konova.models import Geometry, GeometryConflict
from konova.settings import PARCEL_WFS_USER, PARCEL_WFS_PW
from konova.tests.test_views import BaseTestCase
from konova.utils.wfs.spatial import SpatialWFSFetcher
from konova.utils.wfs.spatial import ParcelWFSFetcher
class GeometryTestCase(BaseTestCase):
@ -47,19 +48,21 @@ class GeometryTestCase(BaseTestCase):
self.assertEqual(0, num_conflict)
def test_wfs_fetch(self):
""" Tests the fetching functionality of SpatialWFSFetcher
""" Tests the fetching functionality of ParcelWFSFetcher
+++ Test relies on the availability of the RLP Gemarkung WFS +++
Returns:
"""
fetcher = SpatialWFSFetcher(
base_url="http://geo5.service24.rlp.de/wfs/verwaltungsgrenzen_rp.fcgi",
version="1.1.0",
geometry=self.geom_1
fetcher = ParcelWFSFetcher(
base_url="https://www.geoportal.rlp.de/registry/wfs/519",
version="2.0.0",
geometry=self.geom_1,
auth_user=PARCEL_WFS_USER,
auth_pw=PARCEL_WFS_PW
)
features = fetcher.get_features(
"vermkv:fluren_rlp"
"ave:Flurstueck",
)
self.assertNotEqual(0, len(features), msg="Spatial wfs get feature did not work!")

View File

@ -214,7 +214,7 @@ class BaseTestCase(TestCase):
Returns:
"""
polygon = Polygon.from_bbox((7.157593, 49.882247, 7.816772, 50.266521))
polygon = Polygon.from_bbox((7.5971391556, 50.3600032354, 7.5993975756, 50.3612420894))
polygon.srid = 4326
polygon = polygon.transform(3857, clone=True)
return MultiPolygon(polygon, srid=3857) # 3857 is the default srid used for MultiPolygonField in the form

View File

@ -11,52 +11,68 @@ import requests
import xmltodict
from django.contrib.gis.db.models.functions import AsGML, Transform
from django.contrib.gis.geos import MultiPolygon
from owslib.wfs import WebFeatureService
from requests.auth import HTTPDigestAuth
from konova.models import Geometry
from konova.settings import DEFAULT_SRID_RLP
class BaseWFSFetcher:
# base_url represents not the capabilities url but the parameter-free base url
base_url = ""
version = ""
wfs = None
class AbstractWFSFetcher:
""" Base class for fetching WFS data
def __init__(self, base_url: str, version: str = "1.1.0", *args, **kwargs):
"""
# base_url represents not the capabilities url but the parameter-free base url
base_url = None
version = None
wfs = None
auth_user = None
auth_pw = None
auth_digest_obj = None
class Meta:
abstract = True
def __init__(self, base_url: str, version: str = "1.1.0", auth_user: str = None, auth_pw: str = None, *args, **kwargs):
self.base_url = base_url
self.version = version
self.wfs = WebFeatureService(
url=base_url,
version=version,
)
self.auth_pw = auth_pw
self.auth_user = auth_user
if self.auth_pw is not None and self.auth_user is not None:
self.auth_digest_obj = HTTPDigestAuth(
self.auth_user,
self.auth_pw
)
@abstractmethod
def get_features(self, feature_identifier: str, filter: str):
def get_features(self, feature_identifier: str, filter_str: str):
raise NotImplementedError
class SpatialWFSFetcher(BaseWFSFetcher):
""" Fetches features from a parcel WFS
class ParcelWFSFetcher(AbstractWFSFetcher):
""" Fetches features from a special parcel WFS
"""
geometry = None
geometry_property_name = ""
geometry_property_name = None
count = 100
def __init__(self, geometry: MultiPolygon, geometry_property_name: str = "msGeometry", *args, **kwargs):
super().__init__(*args, **kwargs)
self.geometry = geometry
self.geometry_property_name = geometry_property_name
def _create_geometry_filter(self, geometry_operation: str, filter_srid: str = None):
""" Creates an
def _create_spatial_filter(self,
geometry_operation: str,
filter_srid: str = None):
""" Creates a xml spatial filter according to the WFS filter specification
Args:
geometry_operation ():
filter_srid ():
geometry_operation (str): One of the WFS supported spatial filter operations (according to capabilities)
filter_srid (str): Used to transform the geometry into the spatial reference system identified by this srid
Returns:
spatial_filter (str): The spatial filter element
"""
if filter_srid is None:
filter_srid = DEFAULT_SRID_RLP
@ -67,26 +83,78 @@ class SpatialWFSFetcher(BaseWFSFetcher):
).annotate(
gml=AsGML('transformed')
).first().gml
_filter = f"<Filter><{geometry_operation}><PropertyName>{self.geometry_property_name}</PropertyName>{geom_gml}</{geometry_operation}></Filter>"
spatial_filter = f"<Filter><{geometry_operation}><PropertyName>{self.geometry_property_name}</PropertyName>{geom_gml}</{geometry_operation}></Filter>"
return spatial_filter
def _create_post_data(self,
geometry_operation: str,
filter_srid: str = None,
typenames: str = None,
start_index: int = 0,
):
""" Creates a POST body content for fetching features
Args:
geometry_operation (str): One of the WFS supported spatial filter operations (according to capabilities)
filter_srid (str): Used to transform the geometry into the spatial reference system identified by this srid
Returns:
_filter (str): A proper xml WFS filter
"""
start_index = str(start_index)
spatial_filter = self._create_spatial_filter(
geometry_operation,
filter_srid
)
_filter = f'<wfs:GetFeature service="WFS" version="{self.version}" xmlns:wfs="http://www.opengis.net/wfs/2.0" xmlns:fes="http://www.opengis.net/fes/2.0" xmlns:myns="http://www.someserver.com/myns" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/wfs/2.0 http://schemas.opengis.net/wfs/2.0.0/wfs.xsd" count="{self.count}" startindex="{start_index}"><wfs:Query typeNames="{typenames}">{spatial_filter}</wfs:Query></wfs:GetFeature>'
return _filter
def get_features(self, typenames: str, geometry_operation: str = "Intersects", filter_srid: str = None, filter: str = None):
if filter is None:
filter = self._create_geometry_filter(geometry_operation, filter_srid)
response = requests.post(
url=f"{self.base_url}?request=GetFeature&service=WFS&version={self.version}&typenames={typenames}&count=10",
data={
"filter": filter,
}
)
content = response.content.decode("utf-8")
content = xmltodict.parse(content)
features = content.get(
"wfs:FeatureCollection",
{},
).get(
"gml:featureMember",
[],
)
return features
def get_features(self,
typenames: str,
spatial_operator: str = "Intersects",
filter_srid: str = None,
start_index: int = 0,
):
""" Fetches features from the WFS using POST
POST is required since GET has a character limit around 4000. Having a larger filter would result in errors,
which do not occur in case of POST.
Args:
typenames (str): References to parameter 'typenames' in a WFS GetFeature request
spatial_operator (str): Defines the spatial operation for filtering
filter_srid (str): Defines the spatial reference system, the geometry shall be transformed into for filtering
Returns:
features (list): A list of returned features
"""
features = []
while start_index is not None:
post_body = self._create_post_data(
spatial_operator,
filter_srid,
typenames,
start_index
)
response = requests.post(
url=self.base_url,
data=post_body,
auth=self.auth_digest_obj
)
content = response.content.decode("utf-8")
content = xmltodict.parse(content)
collection = content.get(
"wfs:FeatureCollection",
{},
)
features += collection.get(
"wfs:member",
[],
)
if collection.get("@next", None) is not None:
start_index += self.count
else:
start_index = None
return features