Question

我有一个Django应用程序，它具有PostGIS活动的postgres数据库，我正尝试使用传单和Mapbox映射到前端视图上。

我正在序列化视图中的活动并将其在模板中呈现为geoJSON（{{ props.activitiesJson|safe }}）

[可以将其呈现为html并在页面上查看JSON对象]。

views.py（例如）

def map(request):

    mapbox_key = settings.MAPBOX_API_KEY
    activities = Activity.get_activities_near(lat, lng, radius)

    props = {'activitiesJson' : serializers.serialize('geojson', activities),}

    context = {
    'props' : props,
    'mapbox_key': mapbox_key
}

return render(request, 'app/map.html', context)

模板：

var map_activities = JSON.parse("{{ props.activitiesJson }}");
L.geoJSON(map_activities).addTo(map);

如果我直接在模板上渲染{{ props.activitiesJson }}或{{ props.activitiesJson|safe }}（而不是在脚本内部或对其进行解析），我会看到以下数据结构：

{"type": "FeatureCollection", "crs": {"type": "name", "properties": {"name": "EPSG:4326"}}, "features": [{"type": "Feature", "properties": {"cause": 1, "name": "Test Action", "slug": "test-action", "is_active": true, "image": "test.jpeg", "description": "test description", "date_start": null, "date_end": null, "skills_required": false, "on_site": false, "address_street": "123 Main St.", "address_street_2": "", "address_city": "New York", "address_state": "NY", "address_zip": "10013", "address_country": "", "location_city": "", "location_state": "", "location_country": "", "skills_list": [], "pk": "1"}, "geometry": null}]}

但是尝试使用JSON.parse（）解析它会抛出语法错误：

JSON.parse: expected property name or '}' at line 1 column 2 of the JSON data

如何将那个geoJSON对象有效地分配给我的map_activities变量？我是否需要解析它？（即var map_activities = {{ props.activitiesJson|safe }};）

谢谢

Answer 1

最终（不确定这是否是最佳实践）对我来说正确的方法是根本不解析geoJSON对象并将其直接传递给变量

var map_activities = {{ props.activitiesJson|safe }};

Answer 2

此外，我们可以尝试以下代码。

def map(request):    
   activities = Activity.get_activities_near(lat, lng, radius)
   activitiesData = []
   for activity in activities:
      listdata = {'id': activity.id, 'name': activity.name} # As per requirement
      activitiesData.append(listdata)
   response = HttpResponse(json.dumps(activitiesData))
   return response

将PostGIS点对象转换为geoJSON以进行映射

2 个答案: