Malcolm, (or any other knowledgeable soul), I have been experimenting with both abstract classes and Generic Foreign Keys and Relations to solve my issues, and I still have some problems and questions. There are not a lot of examples of those, and what I really need is for this all to work properly in the admin so I can add a page and in the page inline be able to add any sub-classed "Item". Can you tell me if that type of functionality is supported in Admin yet with generic keys?
Also, I discovered my issue above when I was writing some backend code to generate pages from the data collected in the Admin. The foreign key issue then became apparent. One thing I am trying to wrap my head around however is that when using my original model as above, the Admin app handled everything correctly. I was able to add several different item sub-types individually and attach them to pages without problem, and everything seemed to work fine and things also seemed correct in the database, So I guess I completely see the logic of why a generic key would be required, but the Admin seems to work with what I gave it correctly - I know it has a lot of magic, but I keep going back and thinking if the Admin can work properly with this, there must be a way that I can too. Very frustrating. Thoughts anyone (maybe I am losing it :-) ..... Thanks again, Peter On Sep 16, 9:37 am, Peter Bailey <[EMAIL PROTECTED]> wrote: > Thanks for the responses. There are a number of subclasses and I won't > know the specifics initially. I'll check out the GenericForeighnKey. > Sounds like it is what I want. > > Thanks again, > > Peter > > On Sep 16, 8:34 am, Malcolm Tredinnick <[EMAIL PROTECTED]> > wrote: > > > On Mon, 2008-09-15 at 18:10 -0700, Peter Bailey wrote: > > > Hi all. I have a set of classes (web page items like radios, > > > checkboxes, etc.) They are built on asuperclass- Item. I need a > > > join table to link them to specific pages in which I also store a > > > position (PageItem) . Here is a snippet: > > > > # > > > --------------------------------------------------------------------------- > > > ------- > > > # will use this for subclassing into our item subtypes > > > # > > > --------------------------------------------------------------------------- > > > ------- > > > > class Item(models.Model): > > > name = models.CharField(max_length=30) > > > > def __unicode__(self): > > > return self.name > > > > class Meta: > > > abstract = True > > > > # > > > --------------------------------------------------------------------------- > > > ------- > > > > class Page(models.Model): > > > website = models.ForeignKey(Website) > > > position = models.IntegerField() > > > file_name = models.CharField(max_length=50) > > > h1_title = models.CharField(max_length=50) > > > > def __unicode__(self): > > > return self.file_name > > > > class Meta: > > > ordering = ["file_name"] > > > > # > > > --------------------------------------------------------------------------- > > > ------- > > > > class PageItem(models.Model): > > > page = models.ForeignKey(Page, editable=False) > > > item = models.ForeignKey(Item) # WANT THIS TO POINT TO SPECIFIC > > > SUBCLASS ITEM > > > position = models.IntegerField() > > > > def name(self): > > > return str(self.item.name) > > > > class Meta: > > > ordering = ['position'] > > > > # > > > --------------------------------------------------------------------------- > > > ------- > > > > class RadioBoxType(Item): > > > """A Radio Button object with its specific attributes""" > > > ......... etc. > > > > My problem is that I want the item/page relationship in the join table > > > PageItem, so I can track the position. I realize that I can't have a > > > fk to an abstract class though and obviously want it to point to the > > > subclassed object. > > > So point it at the subclass you want it to point at. > > > If you mean, however, that you want it to point to one of a number of > > possible subclasses, depending on the instance, then that isn't a > > ForeignKey (a ForeignKey points to one particular model). What you're > > modelling in that case is best done with the GenericForeignKey, since > > that encodes both the content type (i.e. the model type) of the target > > as well as the primarykeyvalue. > > > Regards, > > Malcolm --~--~---------~--~----~------------~-------~--~----~ 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?hl=en -~----------~----~----~----~------~----~------~--~---
