Quality of Life improvements

* disables ordering of parcel_group ("Gemarkung") column on tables
    * ordering can not be done properly due to more complex nature of this column's content
* introduces "Keine Geometrie vorhanden" message instead of hour glass icon on entries where no geometry has been entered yet
* properly orders last_modified column by moving null values to the lower end of the ordering

konova/utils/tables.py

@@ -7,11 +7,13 @@ Created on: 25.11.20
 """
 
 from django.core.paginator import PageNotAnInteger, EmptyPage
+from django.db.models import F
 from django.http import HttpRequest
+from django.template.loader import render_to_string
 from django.utils.html import format_html
 import django_tables2 as tables
 
-from konova.models import BaseObject
+from konova.models import BaseObject, GeoReferencedMixin
 from konova.settings import PAGE_SIZE_DEFAULT, PAGE_PARAM, RESULTS_PER_PAGE_PARAM, PAGE_SIZE_OPTIONS
 
 
@@ -173,4 +175,37 @@ class TableRenderMixin:
         max_length = 75
         if len(value) > max_length:
             value = f"{value[:max_length]}..."
-        return value
+        return value
+
+    def render_d(self, value, record: GeoReferencedMixin):
+        """ Renders the parcel district column
+
+        Args:
+            value (str): The intervention geometry
+            record (GeoReferencedMixin): The record
+
+        Returns:
+
+        """
+        parcels = value.get_underlying_parcels().values_list(
+            "parcel_group__name",
+            flat=True
+        ).distinct()
+        html = render_to_string(
+            "table/gmrkng_col.html",
+            {
+                "entries": parcels,
+                "geometry": record.geometry
+            }
+        )
+        return html
+
+
+class TableOrderMixin:
+    """
+    Holds different order_by methods for general purposes
+
+    """
+    def order_lm(self, queryset, is_asc):
+        queryset = queryset.order_by(F('modified__timestamp').desc(nulls_last=True))
+        return (queryset, is_asc)