Add property `isCurrent` to validityranges

aleksis/apps/lesrooster/frontend/components/validity_range/validityRange.graphql

@@ -122,6 +122,7 @@ query timeGrids($orderBy: [String], $filters: JSONString) {
     validityRange {
       id
       name
+      isCurrent
       dateStart
       dateEnd
     }

aleksis/apps/lesrooster/models.py

@@ -72,6 +72,10 @@ class ValidityRange(ExtensibleModel):
         """Get the currently active validity range."""
         return cls.get_current()
 
+    @property
+    def is_current(self) -> bool:
+        return self.date_start <= (today := timezone.now().date()) and self.date_end >= today
+
     def clean(self):
         """Ensure that there is only one validity range at each point of time."""
         if self.date_end < self.date_start:

aleksis/apps/lesrooster/schema/validity_range.py

@@ -18,6 +18,7 @@ from ..models import ValidityRange
 
 
 class ValidityRangeType(PermissionsTypeMixin, DjangoFilterMixin, DjangoObjectType):
+    is_current = graphene.Boolean()
     class Meta:
         model = ValidityRange
         fields = ("id", "school_term", "name", "date_start", "date_end", "status", "time_grids")