track when an object was created or changed and allow querying based on time and versioning (w/ django-reversion support)
HandleRefModel as a base for all your models
from django.db import models from django_handleref.models import HandleRefModel class Test(HandleRefModel): name = models.CharField(max_length=255)
Querying for modification since
It is now possible for you to see which instances of a model have been created or modified since a specific time or version
import time # create instance test = Test.objects.create(name="This is a test") # keep track of time, we need this later t = time.time() # modifying and saving it test.name = "Changed my mind" test.save() # now we can use the handleref manager to retrieve it Test.handleref.since(timestamp=t).count() # 1 Test.handleref.since(timestamp=time.time().count() #0
By default all models extending HandleRefModel will softdelete when their delete() method is called. Note that this currently wont work for batch deletes - as this does not call the delete() method.
test = Test.objects.get(id=1) test.delete() # querying handleref undeleted will not contain the deleted object Test.handleref.undeleted().filter(id=1).count() #0 # querying handleref since will not contain the deleted object Test.handleref.since(timestamp=t).filter(id=1).count() #0 # passing deleted=True to handleref since will contain the deleted object Test.handleref.since(timestamp=t, deleted=True).filter(id=1).count() #1 # querying using the standard objects manager will contain the deleted object Test.objects.filter(id=1).count() #1 # You may also still hard-delete by passing hard=True to delete test.delete(hard=True) Test.objects.filter(id=1).count() #0
Versioning (with django-reversion)
When django-reversion is installed all your HandleRefModels will be valid for versioning.
import reversion with reversion.create_revision(): obj = Test.objects.create(name="This is a test") obj.save() obj.version #1 obj.name = "Changed my mind" obj.save() obj.version #2 Test.handleref.since(version=1).count() #1
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