Python 几何字段的AdminModelConverter（LON/LAT）

我想创建一个视图，以便Flask Admin在几何体字段中输入坐标。如何创建两个文本字段并将其转换为几何体对象

这就是我到目前为止尝试过的（除了数不清的其他东西）

POI对象如下所示：

class POI(db.Model):
    __tablename__ = 'zo_poi'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.Text())
    tags = db.Column(HSTORE())
    src = db.Column(db.Text())
    way = db.Column(Geometry('POINT'))
    intern = db.Column(db.BOOLEAN())

---

非常感谢你的帮助

得到了一个带有交互式地图的解决方案。 以下是我所做的：

admin/fields.py：

import json
from wtforms import Field
import geojson
from shapely.geometry import asShape
from geoalchemy2.shape import to_shape, from_shape
from wtforms.widgets import html_params, HTMLString
from geoalchemy2.elements import WKTElement, WKBElement
from flask import render_template
class WTFormsMapInput(object):
    def __call__(self, field, **kwargs):
        options = dict(name=field.name, value=field.data, height=field.height, width=field.width,
                       geometry_type=field.geometry_type)

        return HTMLString(render_template("admin/admin_map.html", height=options['height'], width=options['width'],
                                          geolayer=self.geolayer(field.data), preview=False))

    def geolayer(self, value):
        if value is not None:
            html = ""
            subme = """var geojson = JSON.parse('%s');
                       editableLayers.addData(geojson);
                       update()
                       map.fitBounds(editableLayers.getBounds());"""
            # If validation in Flask-Admin fails on somethign other than
            # the spatial column, it is never converted to geojson.  Didn't
            # spend the time to figure out why, so I just convert here.
            if isinstance(value, (WKTElement, WKBElement)):
                html += subme % geojson.dumps(to_shape(value))
            else:
                html += subme % geojson.dumps(value)
            return html


class WTFormsMapField(Field):
    widget = WTFormsMapInput()

    def __init__(self, label='', validators=None, geometry_type=None, width=500, height=500,
                 **kwargs):
        super(WTFormsMapField, self).__init__(label, validators, **kwargs)
        self.width = width
        self.height = height
        self.geometry_type = geometry_type

    def _value(self):
        """ Called by widget to get GeoJSON representation of object """
        if self.data:
            return self.data
        else:
            return json.loads(json.dumps(dict()))

    def process_formdata(self, valuelist):
        """ Convert GeoJSON to DB object """
        if valuelist:
            geo_ob = geojson.loads(valuelist[0])
            self.data = from_shape(asShape(geo_ob.geometry))
        else:
            self.data = None

    def process_data(self, value):
        """ Convert DB object to GeoJSON """
        if value is not None:
            self.data = geojson.loads(geojson.dumps(to_shape(value)))
            print self.data
        else:
            self.data = None

模板/admin/admin\u map.html

<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.2/leaflet.css"/>
<link rel="stylesheet" href="http://leaflet.github.io/Leaflet.draw/leaflet.draw.css"/>
<script src="http://cdn.leafletjs.com/leaflet-0.7.2/leaflet.js"></script>
<script src="http://leaflet.github.io/Leaflet.draw/leaflet.draw.js"></script>
<script src="/admin/static/vendor/jquery-1.8.3.min.js" type="text/javascript"></script>
<script src="/static/js/googleOverlay/layer/tile/Google.js"></script>
<script src="http://maps.google.com/maps/api/js?v=3&sensor=false"></script>

<div id="map" style="height: {{ height }}px; width: {{ width }}px;"></div>
<input id="geojson" type="text" name="{{ name }}"/>

<script>
    var map = new L.Map('map', {
                center: new L.LatLng(47.3682, 8.879),
                zoom: 11
                {%  if preview %}
                ,
                    dragging: false,
                    touchzoom: false,
                    scrollWheelZoom: false,
                    doubleClickZoom: false,
                    boxZoom: false,
                    tap: false,
                    keyboard: false,
                    zoomControl: false

                {% endif %}
            }
    );
    var ggl = new L.Google('ROADMAP');
    map.addLayer(ggl);
    var osm = new L.TileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png');
    map.addControl(new L.Control.Layers({'OpenStreetMap': osm, 'Google Maps': ggl}, {}));

    var editableLayers = L.geoJson().addTo(map);

    {{ geolayer |safe }}
    {% if not preview %}
    var drawControl = new L.Control.Draw({
        position: 'topright',
        draw: {
            polyline: false,
            circle: false,
            rectangle: false,
            polygon: true,
            marker: true,
        },
        edit: {
            featureGroup: editableLayers
        }
    });
    {% endif %}
    map.addControl(drawControl);

    map.on('draw:created', function (e) {
        editableLayers.addLayer(e.layer);
        update();
    });

    map.on('draw:edited', function (e) {
        // Just use the first layer
        update();
    })

    map.on('draw:deleted', function (e) {
        update();
    })

    function update() {
        if (editableLayers.getLayers().length > 0) {
            $("#geojson").val(JSON.stringify(editableLayers.getLayers()[0].toGeoJSON()));
        } else {
            $("#geojson").val(null);
        }
    }

</script>

admin/models.py

class POI(db.Model):
    __tablename__ = 'zo_poi'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.Text())
    tags = db.Column(HSTORE())
    src = db.Column(db.Text())
    way = db.Column(Geometry('point', srid=4326))
    intern = db.Column(db.BOOLEAN())

---

从Flask Admin的1.0.9版开始，它现在支持Geoalchemy2几何列（以及1.1.0添加的地理列）

最大的变化是从

flask admin.contrib.geoa

导入

ModelView

，而不是

flask admin.contrib.sqla

，因此一个简单的模型如下所示：

from geoalchemy2 import Geometry
from flask-admin.contrib.geoa import ModelView

app.config['MAPBOX_MAP_ID'] = 'example.abc123'    

class Location(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    point = db.Column(Geometry("Point", 4326))

admin = Admin(app)
admin.add_view(ModelView(Location, db.session))

在列表视图中，每个视图将显示一个小预览地图，然后在“编辑”或“创建视图”中显示一个传单.draw视图

对于直线或复杂多边形，您可能希望使用

form\u widget\u args

覆盖

ModelView

，以获得更合理大小的编辑空间

class Polygon(db.Model):
    ...
    polygon = db.Column(Geometry("Polygon", 4326)

class PolygonView(ModelView):
    form_widget_args = {'polgon': {'data-height': 400; 'data-width': 400}}

admin.add_view(PolygonView(Polygon, db.session))

---

哇！好的，当我再次参与该项目时，我将明确检查这一点：）thx。在当前版本的Flask Admin（1.1.0）中，对几何体列的支持在Mapbox API升级到v4后被破坏@blurrcat新创建的地图不支持v3 API，但对2015年3月15日之前创建的地图的支持尚未关闭。在我的待办事项列表中，要让v4 API支持正常工作。

from geoalchemy2 import Geometry
from flask-admin.contrib.geoa import ModelView

app.config['MAPBOX_MAP_ID'] = 'example.abc123'    

class Location(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    point = db.Column(Geometry("Point", 4326))

admin = Admin(app)
admin.add_view(ModelView(Location, db.session))

class Polygon(db.Model):
    ...
    polygon = db.Column(Geometry("Polygon", 4326)

class PolygonView(ModelView):
    form_widget_args = {'polgon': {'data-height': 400; 'data-width': 400}}

admin.add_view(PolygonView(Polygon, db.session))