common: abstract model for activities

circle/common/models.py

+from django.contrib.auth.models import User
+from django.db.models import (CharField, DateTimeField, ForeignKey, TextField)
+from django.utils import timezone
+from django.utils.translation import ugettext_lazy as _
+from model_utils.models import TimeStampedModel
+
+
+def activitycontextimpl(act):
+    try:
+        yield act
+    except Exception as e:
+        act.finish(str(e))
+        raise e
+    else:
+        act.finish()
+
+
+class ActivityModel(TimeStampedModel):
+    activity_code = CharField(max_length=100, verbose_name=_('activity code'))
+    parent = ForeignKey('self', blank=True, null=True)
+    task_uuid = CharField(blank=True, max_length=50, null=True, unique=True,
+                          help_text=_('Celery task unique identifier.'),
+                          verbose_name=_('task_uuid'))
+    user = ForeignKey(User, blank=True, null=True, verbose_name=_('user'),
+                      help_text=_('The person who started this activity.'))
+    started = DateTimeField(verbose_name=_('started at'),
+                            blank=True, null=True,
+                            help_text=_('Time of activity initiation.'))
+    finished = DateTimeField(verbose_name=_('finished at'),
+                             blank=True, null=True,
+                             help_text=_('Time of activity finalization.'))
+    result = TextField(verbose_name=_('result'), blank=True, null=True,
+                       help_text=_('Human readable result of activity.'))
+
+    class Meta:
+        abstract = True
+
+    def finish(self, result=None):
+        if not self.finished:
+            self.finished = timezone.now()
+            self.result = result
+            self.save()