如何使用django-rest-framework-(gis)展平外键对象

Question

我一直在寻找一个最新且特定于我的问题的解决方案,但是还没有找到解决方案或明确的文档来说明我真正需要做的事情,以便使关系变得平坦以符合geojson.

这个问题几乎与我的问题相同,但是解决方案或答案并没有解决问题,仍然会产生无效的GeoJSON.

• django-rest-framework-gis相关领域

有关

• 将串行器geo_field设置为另一个模型的PointField - Django
• Django REST框架:在嵌套对象中定义字段？

问题

我有一个Location模型,其中包含pointfieldSRID = 4326.我也有一个TrainStation有模型location字段作为外键来Location.当我序列化TrainStation经由GeoFeatureModelSerializer其产生无效GeoJSON的(参见实施例下面的"无效GeoJSON的").

(当然,如果我PointField将TrainStation模型存储在哪里,可以获得有效的GeoJSON ,但在我的情况下,我不能这样做,所以我需要以某种方式压扁它.)

题

• 如何实现输出,如下面的"Valid GeoJSON"示例？

研究

我是Python和Django的新手,因此我还不太擅长阅读其他人的源代码,但我想我可以得出结论,我需要以某种方式覆盖该to_representation()方法以获得我想要的东西,但我的搜索是如此没有结果,所以我被卡住了.

models.py

class Location(models.Model):

    point = models.PointField()

class TrainStation(models.Model):

    location_signature = models.CharField(primary_key=True, max_length=32)
    advertised_location_name = models.CharField(max_length=32)
    country_code = models.ForeignKey(Country)
    county_no = models.ForeignKey(County)
    location = models.ForeignKey(Location, null=True)

serializers.py

class LocationSerializer(ModelSerializer):

    class Meta:
        model = Location
        geo_field = 'point'
        fields = [
            'point',
        ]


class TrainStationSerializer(GeoFeatureModelSerializer):

    location_signature = PrimaryKeyRelatedField(read_only=True)
    location = LocationSerializer(read_only=True)
    country_code = StringRelatedField(read_only=True)
    county_no = StringRelatedField(read_only=True)

    class Meta:
        model = TrainStation
        geo_field = 'location'
        fields = [
            'location_signature',
            'advertised_location_name',
            'country_code',
            'county_no',
        ]

GeoJSON输出示例:

我已经验证了http://geojson.io上的输出,以确定它是否有效.

无效的GeoJSON

{
    "type": "FeatureCollection",
    "features": [
        {
            "id": "Ak",
            "type": "Feature",
            "geometry": {
                "point": {           <------+------ offending lines
                    "type": "Point",        |
                    "coordinates": [        |
                        18.8303462142963,   |
                        68.3486410812835    |
                    ]                       |
                }                    <------+
            },
            "properties": {
                "advertised_location_name": "Abisko Östra",
                "country_code": "Sverige",
                "county_no": "Norrbottens län"
            }
        }
    ]
}

有效的GeoJSON

这是我要找的输出.

{
    "type": "FeatureCollection",
    "features": [
        {
            "id": "Ak",
            "type": "Feature",
            "geometry": {
                "type": "Point",
                "coordinates": [
                    18.8303462142963,
                    68.3486410812835
                ]
            },
            "properties": {
                "advertised_location_name": "Abisko Östra",
                "country_code": "Sverige",
                "county_no": "Norrbottens län"
            }
        }
    ]
}

Answer 1

我现在已经用以下代码解决了这个问题：

\n\n

class LocationSerializer(ModelSerializer):\n\n    def to_representation(self, obj):\n\n        representation = super().to_representation(obj)\n        point_representation = representation.pop(\'point\')\n        for key in point_representation:\n            representation[key] = point_representation[key]\n\n        return representation\n\n    class Meta:\n        model = Location\n        geo_field = \'point\'\n        fields = [\n            \'point\',\n        ]\n

\n\n

这确实产生了有效的 GeoJSON：

\n\n

{\n    "type": "FeatureCollection",\n    "features": [\n        {\n            "id": "Ak",\n            "type": "Feature",\n            "geometry": {\n                "type": "Point",\n                "coordinates": [\n                    18.8303462142963,\n                    68.3486410812835\n                ]\n            },\n            "properties": {\n                "advertised_location_name": "Abisko \xc3\x96stra",\n                "country_code": "Sverige",\n                "county_no": "Norrbottens l\xc3\xa4n"\n            }\n        }\n    ]\n}\n

\n\n

如果有人对此有任何意见，请随时贡献并添加答案:-)

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