I want to create a view for Flask-Admin to enter coordinates in a Geometry Field. How can I create two Textfields and convert them into the Geometry Object?
This is what I have tried so far (Besides uncountable other things)
class CustomAdminConverter(AdminModelConverter):
@converts('geoalchemy2.types.Geometry')
def convert_geometry(self, field_args, **extra):
return WayToCoordinatesField(**field_args)
class WayToCoordinatesField(wtf.TextAreaField):
def process_data(self, value):
print "run" #is never called??
if value is None:
value = {}
else:
value = "test"
return value
class POIView(ModelView):
inline_model_form_converter = MyInlineModelConverter
model_form_converter=CustomAdminConverter
can_create = True
def __init__(self, session, **kwargs):
# You can pass name and other parameters if you want to
super(POIView, self).__init__(POI, session, **kwargs)
def scaffold_form(self):
form_class = super(POIView, self).scaffold_form()
form_class.way = wtf.TextAreaField("Coordinates")
return form_class
The POI Object looks like this:
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())
Thanks a lot for your help!
Got a solution with a interactive Map. Here is what I have done:
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
templates/admin/admin_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/views.py
class POIView(ModelView):
can_create = True
form_overrides = dict(location=WTFormsMapField)
form_args = dict(
way=dict(
geometry_type='Polygon', height=500, width=500
)
)
column_formatters = dict(tags=lambda v, c, m, p: (u', '.join(u"=".join([k, v]) for k, v in m.tags.items())),
)
def __init__(self, session, **kwargs):
super(POIView, self).__init__(POI, session, **kwargs)
def scaffold_form(self):
form_class = super(POIView, self).scaffold_form()
form_class.way = WTFormsMapField()
form_class.tags = MySelect2TagsField("Tags",None)
return form_class
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())