konova/konova/forms/geometry_form.py
mpeltriaux 7bcd32fd7a # Netgis client update
* minor changes to configuration
2025-10-12 11:30:04 +02:00

243 lines
7.9 KiB
Python

"""
Author: Michel Peltriaux
Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
Contact: ksp-servicestelle@sgdnord.rlp.de
Created on: 15.08.22
"""
import json
from django.contrib.gis import gdal
from django.contrib.gis.geos import MultiPolygon, Polygon
from django.contrib.gis.geos.prototypes.io import WKTWriter
from django.utils.translation import gettext_lazy as _
from django.forms import JSONField
from konova.forms.base_form import BaseForm
from konova.models import Geometry
from konova.settings import GEOM_MAX_VERTICES
from konova.tasks import celery_update_parcels, celery_check_for_geometry_conflicts
from konova.sub_settings.lanis_settings import DEFAULT_SRID_RLP
from user.models import UserActionLogEntry
class SimpleGeomForm(BaseForm):
""" A geometry form for rendering geometry read-only using a widget
"""
read_only = True
geometry_simplified = False
output = JSONField(
label=_("Geometry"),
help_text=_(""),
label_suffix="",
required=False,
disabled=False,
)
def __init__(self, *args, **kwargs):
self.read_only = kwargs.pop("read_only", True)
super().__init__(*args, **kwargs)
# Initialize geometry
try:
geom = self.instance.geometry.geom
self.empty = geom.empty
if self.empty:
raise AttributeError
geojson = self.instance.geometry.as_feature_collection(srid=DEFAULT_SRID_RLP)
geom = json.dumps(geojson)
except AttributeError:
# If no geometry exists for this form, we simply set the value to None and zoom to the maximum level
geom = ""
self.empty = True
self.initialize_form_field("output", geom)
def is_valid(self):
super().is_valid()
is_valid = True
# Get geojson from form
geom = self.data["output"]
if geom is None or len(geom) == 0:
# empty geometry is a valid geometry
self.cleaned_data["output"] = MultiPolygon(srid=DEFAULT_SRID_RLP).ewkt
return is_valid
geom = json.loads(geom)
# Write submitted data back into form field to make sure invalid geometry
# will be rendered again on failed submit
self.initialize_form_field("output", self.data["output"])
# Initialize features list with empty MultiPolygon, so that an empty input will result in a
# proper empty MultiPolygon object
features = []
features_json = geom.get("features", [])
accepted_ogr_types = [
"Polygon",
"Polygon25D",
"MultiPolygon",
"MultiPolygon25D",
]
for feature in features_json:
feature_geom = feature.get("geometry", feature)
if feature_geom is None:
# Fallback for rare cases where a feature does not contain any geometry
continue
feature_geom = json.dumps(feature_geom)
g = gdal.OGRGeometry(feature_geom, srs=DEFAULT_SRID_RLP)
flatten_geometry = g.coord_dim > 2
if flatten_geometry:
g = self.__flatten_geom_to_2D(g)
if g.geom_type not in accepted_ogr_types:
self.add_error("output", _("Only surfaces allowed. Points or lines must be buffered."))
is_valid &= False
return is_valid
is_valid &= self.__is_area_valid(g)
g = Polygon.from_ewkt(g.ewkt)
is_valid &= g.valid
if not g.valid:
self.add_error("output", g.valid_reason)
return is_valid
if isinstance(g, Polygon):
features.append(g)
elif isinstance(g, MultiPolygon):
features.extend(list(g))
# Unionize all geometry features into one new MultiPolygon
if features:
form_geom = MultiPolygon(*features, srid=DEFAULT_SRID_RLP).unary_union
else:
form_geom = MultiPolygon(srid=DEFAULT_SRID_RLP)
# Make sure to convert into a MultiPolygon. Relevant if a single Polygon is provided.
form_geom = Geometry.cast_to_multipolygon(form_geom)
# Write unioned Multipolygon into cleaned data
if self.cleaned_data is None:
self.cleaned_data = {}
self.cleaned_data["output"] = form_geom.ewkt
return is_valid
def __is_vertices_num_valid(self):
""" Checks whether the number of vertices in the geometry is not too high
Returns:
"""
geom = self.cleaned_data.get("output")
g = gdal.OGRGeometry(geom, srs=DEFAULT_SRID_RLP)
num_vertices = g.num_coords
return num_vertices <= GEOM_MAX_VERTICES
def __is_area_valid(self, geom: gdal.OGRGeometry):
""" Checks whether the area is at least > 1m²
Returns:
"""
is_area_valid = geom.area > 1 # > 1m² (SRID:25832)
if not is_area_valid:
self.add_error(
"output",
_("Geometry must be greater than 1m². Currently is {}").format(
float(geom.area)
)
)
return is_area_valid
def __simplify_geometry(self, geom, max_vert: int):
""" Simplifies a geometry
Geometry will be simplified until a threshold of max vertices has been reached.
Args:
geom (MultiPolygon): The geometry
max_vert (int): Threshold of maximum vertices in geometry
Returns:
geom (MultiPolygon): The simplified geometry
"""
tolerance = 0.1
n = geom.num_coords
while(n > max_vert):
geom = geom.simplify(tolerance)
n = geom.num_coords
tolerance += 0.1
return geom
def save(self, action: UserActionLogEntry):
""" Saves the form's geometry
Creates a new geometry entry if none is set, yet
Args:
action ():
Returns:
"""
try:
if self.instance is None or self.instance.geometry is None:
raise LookupError
geometry = self.instance.geometry
geometry.geom = self.cleaned_data.get("output", MultiPolygon(srid=DEFAULT_SRID_RLP))
geometry.modified = action
geometry.save()
except LookupError:
# No geometry or linked instance holding a geometry exist --> create a new one!
geometry = Geometry.objects.create(
geom=self.cleaned_data.get("output", MultiPolygon(srid=DEFAULT_SRID_RLP)),
created=action,
)
is_vertices_num_valid = self.__is_vertices_num_valid()
if not is_vertices_num_valid:
geometry.geom = self.__simplify_geometry(geometry.geom, max_vert=GEOM_MAX_VERTICES)
geometry.save()
self.geometry_simplified = True
# Start parcel update and geometry conflict checking procedure in a background process
celery_update_parcels.delay(geometry.id)
celery_check_for_geometry_conflicts.delay(geometry.id)
return geometry
def __flatten_geom_to_2D(self, geom):
"""
Enforces a given OGRGeometry from higher dimensions into 2D
"""
wkt_w = WKTWriter(dim=2)
g_wkt = wkt_w.write(geom.geos).decode("utf-8")
geom = gdal.OGRGeometry(g_wkt)
return geom
def _set_properties(self, geojson: dict, title: str):
""" Toggles the editable property of the geojson for proper handling in map client
Args:
geojson (dict): The GeoJson
Returns:
geojson (dict): The altered GeoJson
"""
features = geojson.get("features", [])
for feature in features:
feature["properties"]["editable"] = not self.read_only
if title:
feature["properties"]["title"] = title
return geojson