Merge #155

155: Military symbols for narrations. r=MiklerGM a=whirish

Closes #94. Adds two models - `Symbol` and `SymbolFeature`. Symbol is intended to be a single FeatureCollection storing individual SymbolFeatures, and has a o2m relationship with SymbolFeature as a result. SymbolFeatures stores geometry and an hstore field `styling`, which will store styling information as GeoJSON `properties`. 
Symbol features have a GeoJSON-compatible endpoint, and can be requested as  `/api/symbol-features/?symbol=<symbol id>/`, which returns a FeatureCollection containing all SymbolFeatures for a specified Symbol ID. @MiklerGM please tell me if this arrangement works for you. We can also add query params for filtering based on narration IDs, etc.
Old Chronist narratives should be available for import after this is merged.

Co-authored-by: whirish <lpoflynn@protonmail.ch>

project/api/admin.py

@@ -30,6 +30,8 @@
     City,
     Profile,
     NarrativeVote,
+    Symbol,
+    SymbolFeature,
 )
 
 # Register your models here.
@@ -43,3 +45,5 @@
 admin.site.register(City)
 admin.site.register(Profile)
 admin.site.register(NarrativeVote)
+admin.site.register(Symbol)
+admin.site.register(SymbolFeature)

project/api/migrations/0016_historicalsymbol_symbol_symbolfeature.py

@@ -0,0 +1,55 @@
+# Generated by Django 2.2.4 on 2019-08-08 19:58
+
+from django.conf import settings
+import django.contrib.gis.db.models.fields
+from django.contrib.postgres.operations import HStoreExtension
+import django.contrib.postgres.fields.hstore
+from django.db import migrations, models
+import django.db.models.deletion
+import simple_history.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('api', '0015_merge_20190627_1103'),
+    ]
+
+    operations = [
+        HStoreExtension(),
+        migrations.CreateModel(
+            name='Symbol',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.TextField(max_length=50)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='SymbolFeature',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('geom', django.contrib.gis.db.models.fields.GeometryField(srid=4326)),
+                ('styling', django.contrib.postgres.fields.hstore.HStoreField()),
+                ('symbol', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='features', to='api.Symbol')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='HistoricalSymbol',
+            fields=[
+                ('id', models.IntegerField(auto_created=True, blank=True, db_index=True, verbose_name='ID')),
+                ('name', models.TextField(max_length=50)),
+                ('history_id', models.AutoField(primary_key=True, serialize=False)),
+                ('history_date', models.DateTimeField()),
+                ('history_change_reason', models.CharField(max_length=100, null=True)),
+                ('history_type', models.CharField(choices=[('+', 'Created'), ('~', 'Changed'), ('-', 'Deleted')], max_length=1)),
+                ('history_user', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'historical symbol',
+                'ordering': ('-history_date', '-history_id'),
+                'get_latest_by': 'history_date',
+            },
+            bases=(simple_history.models.HistoricalChanges, models.Model),
+        ),
+    ]

project/api/migrations/0017_symbol_narration.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.4 on 2019-08-08 23:07
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0016_historicalsymbol_symbol_symbolfeature'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='symbol',
+            name='narration',
+            field=models.ManyToManyField(related_name='symbols', to='api.Narration'),
+        ),
+    ]

project/api/migrations/0018_auto_20190809_0035.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.4 on 2019-08-09 00:35
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0017_symbol_narration'),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name='symbol',
+            old_name='narration',
+            new_name='narrations',
+        ),
+    ]

project/api/models.py

@@ -21,7 +21,7 @@
 from django.core.exceptions import ValidationError
 from django.contrib.auth.models import User
 from django.contrib.gis.db import models
-from django.contrib.postgres.fields import ArrayField
+from django.contrib.postgres.fields import ArrayField, HStoreField
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 from ordered_model.models import OrderedModel
@@ -385,3 +385,25 @@ class Narration(OrderedModel):
     location = models.PointField(blank=True, null=True)
 
     order_with_respect_to = "narrative"
+
+
+class Symbol(models.Model):
+    """
+    Stores a FeatureCollection in representation of something
+    """
+
+    name = models.TextField(max_length=50)
+    narrations = models.ManyToManyField(Narration, related_name="symbols")
+    history = HistoricalRecords()
+
+
+class SymbolFeature(models.Model):
+    """
+    Stores geometry to be used in a collection in a Symbol
+    """
+
+    geom = models.GeometryField()
+    styling = HStoreField()
+    symbol = models.ForeignKey(
+        Symbol, related_name="features", on_delete=models.CASCADE
+    )

project/api/serializers.py

@@ -25,10 +25,13 @@
     PrimaryKeyRelatedField,
     SerializerMethodField,
 )
+from rest_framework_gis.serializers import GeoFeatureModelSerializer
 
 from .models import (
     TerritorialEntity,
     PoliticalRelation,
+    Symbol,
+    SymbolFeature,
     CachedData,
     City,
     SpacetimeVolume,
@@ -119,6 +122,38 @@ class Meta:
         read_only_fields = ("rank",)
 
 
+class SymbolFeatureSerializer(GeoFeatureModelSerializer):
+    """
+    Symbolizes SymbolFeatures as valid GeoJSON
+    """
+
+    class Meta:
+        model = SymbolFeature
+        geo_field = "geom"
+        fields = "__all__"
+
+    def get_properties(self, instance, fields):
+        return instance.styling
+
+    def unformat_geojson(self, feature):
+        attrs = {
+            self.Meta.geo_field: feature["geometry"],
+            "styling": feature["properties"],
+        }
+
+        return attrs
+
+
+class SymbolSerializer(ModelSerializer):
+    """
+    Serializes the Symbol model
+    """
+
+    class Meta:
+        model = Symbol
+        fields = ("id", "name", "narrations", "features")
+
+
 class CitySerializer(ModelSerializer):
     """
     Serializes the City model

project/api/urls.py

@@ -33,6 +33,8 @@
 ROUTER.register(r"narrations", views.NarrationViewSet)
 ROUTER.register(r"narrative-votes", views.NarrativeVoteViewSet)
 ROUTER.register(r"profiles", views.ProfileViewSet)
+ROUTER.register(r"symbols", views.SymbolViewSet)
+ROUTER.register(r"symbol-features", views.SymbolFeatureViewSet)
 
 urlpatterns = [
     path(

project/api/views.py

@@ -35,6 +35,8 @@
     Narration,
     NarrativeVote,
     Profile,
+    Symbol,
+    SymbolFeature,
 )
 from .serializers import (
     TerritorialEntitySerializer,
@@ -47,6 +49,8 @@
     NarrationSerializer,
     NarrativeVoteSerializer,
     ProfileSerializer,
+    SymbolSerializer,
+    SymbolFeatureSerializer,
 )
 from .permissions import IsUserOrReadOnly
 
@@ -184,6 +188,31 @@ def get_queryset(self):
         return queryset
 
 
+class SymbolFeatureViewSet(viewsets.ModelViewSet):
+    """
+    ViewSet for SymbolFeatures, filterable by Symbol id
+    """
+
+    queryset = SymbolFeature.objects.all()
+    serializer_class = SymbolFeatureSerializer
+
+    def get_queryset(self):
+        queryset = self.queryset
+        symbol = self.request.query_params.get("symbol", None)
+        if symbol is not None:
+            queryset = queryset.filter(symbol=symbol)
+        return queryset
+
+
+class SymbolViewSet(viewsets.ModelViewSet):
+    """
+    ViewSet for Symbols
+    """
+
+    queryset = Symbol.objects.all()
+    serializer_class = SymbolSerializer
+
+
 class ProfileViewSet(viewsets.ModelViewSet):
     """
     ViewSet for Profile

project/chron/settings.py

@@ -46,6 +46,7 @@
     "django.contrib.messages",
     "django.contrib.staticfiles",
     "django.contrib.gis",
+    "django.contrib.postgres",
     "django_extensions",
     "api.apps.ApiConfig",
     "colorfield",