好吧,我尝试在使用geojson序列化程序成功进行序列化后,将模型(称为Highway)中定义的函数添加到模型(Highway)的HttpResponse中。
由于没有传递任何错误并且该属性未出现在HttpResponse中,因此我试图通过遍历源代码来查找解决方案。但是,我可能会使事情变得复杂,并希望可以对此有所关注。我愿意接受其他建议,也许每次添加/修改位置时都要更新“高速公路”。
将该项目传递到管理站点时正确显示,并且所有其他字段(以下未显示)均按预期工作。
PS。我是整个Django系统的新手。谢谢!
Django版本:2.1
相关链接:
geom.models.py
class Highway(models.Model):
name = models.CharField(max_length=50, unique=True)
length = models.IntegerField("Length in meters")
mline = models.MultiLineStringField("Geometry", srid=4326)
def cameras_per_km(self):
#THIS IS THE FUNCTION I AM TRYING TO SEND TO GEOJSON SERIALIZER
count = self.location_set.filter(location__icontains="camera").count()
return round(count/(self.length/1000),1)
cameras_per_km.short_description = "Cameras/km"
class Location(models.Model):
location = models.CharField(max_length=30, unique=True)
highway = models.ForeignKey(Highway, null=True, on_delete=models.SET_NULL)
point = models.PointField()
geom.admin.py (将功能传递到list_display时,该项目在admin中显示为正确)
class HighwayAdmin(LeafletGeoAdmin):
list_display = ('name', 'cameras_per_km')
admin.site.register(
Highway,
HighwayAdmin,
)
geom.views.py (不是)
def geojson_highway_all(request):
geojsonformat = serialize('geojson',
Highway.objects.all(),
geometry_field='mline',
fields = (
'pk',
'cameras_per_km' # <-- I want this to show
)
)
return HttpResponse(geojsonformat)
geom.urls.py
from django.urls import path
from . import views
app_name = 'geom'
urlpatterns = [
path('highways.geojson', views.geojson_highway_all, name='highways.geojson'),
]
答案 0 :(得分:1)
更新:我(Anton vBR)现在已经完全重写了此答案,但认为@ruddra应该得到一些荣誉。但是,我愿意接受其他解决方案。希望这个答案可以在将来帮助某个人。
基于geojson序列化器创建新的序列化器
geom.views.py
from django.contrib.gis.serializers.geojson import Serializer
class CustomSerializer(Serializer):
def end_object(self, obj):
for field in self.selected_fields:
if field == self.geometry_field or field == 'pk':
continue
elif field in self._current.keys():
continue
else:
try:
self._current[field] = getattr(obj, field)()
except AttributeError:
pass
super(CustomSerializer, self).end_object(obj)
geojsonformat = CustomSerializer().serialize(
Highway.objects.all(),
geometry_field='mline',
fields = (
'pk',
'cameras_per_km'
)