I have been thinking about how to do something similar - specifically,
wikipage history. Note that I have not actually tried any of this yet
but I would split the history out into a second table. Perhaps this
incomplete example to illustrate:
class Page(models.Model):
title = models.CharField(maxlength=30)
content = models.TextField()
status = models...
class PageHistory(models.Model):
title = models.CharField(maxlength=30)
content = models.TextField()
page = models.ForeignKey(Page)
date = models.DateField()
comment = models.textField()
author = models.ForeignKey(User)
Whenever a page is saved, the data in Page is overwritten and a new
record is added to PageHistory with the ForeignKey pointing back to
page. (Should PageHistory contain the current version of Page or only
previous versions? I'm not sure. The former feels more secure but the
later more DRY.) The only time PageHistory is accessed is if one needs
to review the history. I suppose this is a fancy form of logging.
The problem I'm not sure how to address is if a Page is deleted. To
preserve the history, the records should stay in PageHistory, but if
the record is deleted from Page, then we leave a ForeignKey hanging.
Perhaps a status field should be altered on delete. Subclassing the
save() and delete() methods for Page should do the trick.
In my case this only needs to be done for one model. Sounds like you
need to do this for every model which could get a little unweildy. I
don't know that I helped much.
On 6/13/06, Paul Childs <[EMAIL PROTECTED]> wrote:
>
> I have been using Django for about a month now and I just moved over to
> the development version.
>
> I am creating an application in which the client has dictated very
> stringent database record management in order to have a detailed audit
> trail on all changes made data. This does not necessarily mean logging.
>
> The rules are quite simple.
>
> · once saved, records are immutable.
> · records can not be deleted. they must be marked for deletion only.
> · to "edit" a record a new record is created with the new changes
> and a reference must point back to the old record
> · a comment must be attached to every edit or delete to explain why
> the action was taken.
>
> I was planning on doing this with a combination of Managers, Views and
> overriding the delete() and save() methods of my models. I have done
> some experimentation and found this to be awkward, not very elegant and
> to contravention of the DRY principle.
>
> Is there a better way of achieving this or am I on the right track?
>
>
> >
>
--
----
Waylan Limberg
[EMAIL PROTECTED]
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Django users" group.
To post to this group, send email to django-users@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/django-users
-~----------~----~----~----~------~----~------~--~---
