Add observer field on DemodData

db/base/admin.py

@@ -104,7 +104,7 @@ class TelemetryAdmin(admin.ModelAdmin):
 
 @admin.register(DemodData)
 class DemodDataAdmin(admin.ModelAdmin):
-    list_display = ('id', 'satellite', 'source', 'station')
+    list_display = ('id', 'satellite', 'source', 'observer')
     search_fields = ('transmitter__uuid', 'satellite__norad_cat_id', 'observer')
 
     def satellite(self, obj):

db/base/migrations/0005_demoddata_observer.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.6 on 2017-03-14 18:38
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('base', '0004_auto_20170302_1641'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='demoddata',
+            name='observer',
+            field=models.CharField(blank=True, max_length=60),
+        ),
+    ]

db/base/models.py

@@ -4,6 +4,7 @@ from uuid import uuid4
 
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
+from django.db.models.signals import post_save
 from django.contrib.auth.models import User
 from django.conf import settings
 
@@ -19,6 +20,18 @@ def _name_payload_frame(instance, filename):
     return path.join(folder, filename)
 
 
+def _gen_observer(sender, instance, created, **kwargs):
+    post_save.disconnect(_gen_observer, sender=DemodData)
+    try:
+        qth = gridsquare(instance.lat, instance.lng)
+    except:
+        instance.observer = 'Unknown'
+    else:
+        instance.observer = '{0}-{1}'.format(instance.station, qth)
+    instance.save()
+    post_save.connect(_gen_observer, sender=DemodData)
+
+
 class TransmitterApprovedManager(models.Manager):
     def get_queryset(self):
         return super(TransmitterApprovedManager, self).get_queryset().filter(approved=True)
@@ -148,6 +161,7 @@ class DemodData(models.Model):
     payload_decoded = models.TextField(blank=True)
     payload_telemetry = models.ForeignKey(Telemetry, null=True, blank=True)
     station = models.CharField(max_length=45, default='Unknown')
+    observer = models.CharField(max_length=60, blank=True)
     lat = models.FloatField(validators=[MaxValueValidator(90), MinValueValidator(-90)],
                             default=0)
     lng = models.FloatField(validators=[MaxValueValidator(180), MinValueValidator(-180)],
@@ -157,13 +171,7 @@ class DemodData(models.Model):
     class Meta:
         ordering = ['-timestamp']
 
-    @property
-    def qthlocation(self):
-        try:
-            qth = gridsquare(self.lat, self.lng)
-        except:
-            qth = 'Unknown'
-        return qth
-
     def __unicode__(self):
         return 'data-for-{0}'.format(self.satellite.norad_cat_id)
+
+post_save.connect(_gen_observer, sender=DemodData)