66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
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from django.apps import apps
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from django.contrib.gis.db.models import GeometryField
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from django.contrib.gis.db.models.functions import AsKML, Transform
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from django.contrib.gis.shortcuts import render_to_kml, render_to_kmz
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from django.core.exceptions import FieldDoesNotExist
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from django.db import DEFAULT_DB_ALIAS, connections
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from django.http import Http404
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def kml(request, label, model, field_name=None, compress=False, using=DEFAULT_DB_ALIAS):
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"""
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This view generates KML for the given app label, model, and field name.
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The field name must be that of a geographic field.
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"""
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placemarks = []
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try:
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klass = apps.get_model(label, model)
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except LookupError:
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raise Http404(
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'You must supply a valid app label and module name. Got "%s.%s"'
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% (label, model)
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)
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if field_name:
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try:
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field = klass._meta.get_field(field_name)
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if not isinstance(field, GeometryField):
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raise FieldDoesNotExist
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except FieldDoesNotExist:
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raise Http404("Invalid geometry field.")
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connection = connections[using]
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if connection.features.has_AsKML_function:
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# Database will take care of transformation.
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placemarks = klass._default_manager.using(using).annotate(kml=AsKML(field_name))
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else:
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# If the database offers no KML method, we use the `kml`
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# attribute of the lazy geometry instead.
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placemarks = []
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if connection.features.has_Transform_function:
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qs = klass._default_manager.using(using).annotate(
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**{"%s_4326" % field_name: Transform(field_name, 4326)}
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)
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field_name += "_4326"
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else:
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qs = klass._default_manager.using(using).all()
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for mod in qs:
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mod.kml = getattr(mod, field_name).kml
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placemarks.append(mod)
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# Getting the render function and rendering to the correct.
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if compress:
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render = render_to_kmz
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else:
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render = render_to_kml
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return render("gis/kml/placemarks.kml", {"places": placemarks})
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def kmz(request, label, model, field_name=None, using=DEFAULT_DB_ALIAS):
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"""
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Return KMZ for the given app label, model, and field name.
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"""
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return kml(request, label, model, field_name, compress=True, using=using)
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