Django models RecordStatusHistoryMixin (pre_save hook)

django-models-record-status-history-mixin.py

from django.db import models
from jsonfield import JSONField
from dirtyfields import DirtyFieldsMixin
import time

class RecordStatusHistoryMixin(DirtyFieldsMixin):
    def save(self, *args, **kwargs):
        if not self.pk:
            # first create
            current_time = int(time.time())
            self.status_history.append(dict(
                timestamp=current_time, status=self.status))
        elif self.is_dirty():
            dirty_fields = self.get_dirty_fields()
            if "status" in dirty_fields:
                # status changed, write history
                current_time = int(time.time())
                self.status_history.append(dict(
                    timestamp=current_time, status=self.status))
        super(RecordStatusHistoryMixin, self).save(*args, **kwargs)
        
class Job(RecordStatusHistoryMixin, models.Model):
    status              = models.CharField(max_length=32)
    status_history      =        JSONField(blank=True, default=[])

Should use self.pk to determine if it's first time (create). Fixed in rev #3