added first public views - no check for access rights at the moment

lib/core/db/models/base.py

@@ -0,0 +1,31 @@
+from functools import cached_property
+
+from django.contrib.auth.models import User
+from django.db import models
+
+from lib.core.db.models.mixins import DateAware
+
+
+class SharedPermissionBase(DateAware, models.Model):
+    class Meta:
+        abstract = True
+
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    view = models.BooleanField(default=True)
+    change = models.BooleanField(default=False)
+    delete = models.BooleanField(default=False)
+    add = models.BooleanField(default=False)
+
+    # item = models.IntegerField(default=NotImplementedError('Must be defined in inheriting class'))
+    @cached_property
+    def perms(self):
+        perms = filter(None, [
+            'read' if self.view else False,
+            'change' if self.change else False,
+            'delete' if self.delete else False,
+            'add' if self.add else False,
+        ])
+        return list(perms)
+
+    def __str__(self):
+        return f'{self.user.username} ({", ".join(self.perms)})'