Reading GeoJSON keys and values from na Openlayers feature - django

Question

I'm using OpenLayers to create, display and edit features on the map. Features are saved as a JSONField in Django. Post Save I add a key django_pk to the JSON. How can I get this djanog_pk directly from the feature?
I need to do this so when the feature is edited, I know what feature to update in Django.
My JS code below:
<script>
var raster = new ol.layer.Tile({
source: new ol.source.OSM()
});
var source = new ol.source.Vector({wrapX: false});
var vector = new ol.layer.Vector({
source: source
});
var format = new ol.format.GeoJSON();
var select = new ol.interaction.Select({
wrapX: false
});
var modify = new ol.interaction.Modify({
features: select.getFeatures()
});
var map = new ol.Map({
interactions: ol.interaction.defaults().extend([select, modify]),
layers: [raster, vector],
target: 'map',
view: new ol.View({
center: [-11000000, 4600000],
zoom: 4
})
});
var features = new ol.source.Vector({
projection: 'EPSG:4326'
});
{% for polygon in polygons.0.gates %}
console.log(format.readFeature({{ polygon|safe }}).getProperties()))
{% endfor %}
features.addFeature(format.readFeature({{ polygons.0.protected_area|safe }}));
{% for polygon in polygons.0.gates %}
features.addFeature(format.readFeature({{ polygon|safe }}));
console.log(format.readFeature({{ polygon|safe }}))
{% endfor %}
var featureOverlay = new ol.layer.Vector({
source: features,
style: new ol.style.Style({
fill: new ol.style.Fill({
color: 'rgba(255, 255, 255, 0.2)'
}),
stroke: new ol.style.Stroke({
color: '#ff78d1',
width: 2
}),
image: new ol.style.Circle({
radius: 6,
fill: new ol.style.Fill({
color: '#4ca6b6'
}),
})
})
});
featureOverlay.setMap(map);
</script>
I tried this: Buyt it only return geometry:
select.on('select', function(e) {
console.log(e.selected[0].getProperties())
});
The JSONField in Django looks like this:
{
"geometry":{
"type":"Polygon",
"coordinates":[
[
[
-11156543.033928039,
6698655.0485978
],
[
-11410925.464061106,
5896371.999716589
],
[
-9972686.33984723,
5084305.011214877
],
[
-9512841.177683609,
6649735.350495286
],
[
-10090093.61529326,
6972605.357971871
],
[
-11156543.033928039,
6698655.0485978
]
]
]
},
"type":"Feature",
"properties":null,
"django_pk":10
}
So I need to find the django_pk for a feature when editing it, it selecting it, ot deleting it.
Not sure how to get this information

Answer 1

Ok, I its actually simple.
You can read any property of the GeoJSON format:
select.on('select', function(e) {
console.log(e.selected[0].getProperties())
});
Select being:
var select = new ol.interaction.Select({
wrapX: false
});
And in my Django code I just do this on post_save:
#receiver(post_save, sender=ProtectedArea)
def update_json(sender, instance, created, **kwargs):
post_save.disconnect(update_json, sender=ProtectedArea)
try:
instance.polygone = literal_eval("%s" % instance.geojson_file.read())
except:
pass
if instance.polygone['properties'] == None:
instance.polygone['properties'] = {}
instance.polygone['properties']['pk'] = instance.pk
else:
instance.polygone['properties']['pk'] = instance.pk
instance.save()
post_save.connect(update_json, sender=ProtectedArea)