*UPDATE:* * * I was able to resolve the problem by looking up the contenttype manually so,
ct = orm['contenttypes.ContentType'].*objects.*get(app_label="blog", model="Post") Thanks Tom & Andrew (at south user listserv) for helping with this. On Sat, Aug 13, 2011 at 1:14 PM, Chintan Tank <tankchin...@gmail.com> wrote: > Tom, > I tried looking up the content_type and then using it, but it still throws > errors. > > *1. I tried* > > ct = ContentType.objects.get_for_model(Post) > chapter = orm.Chapter(rank=1, content_type=ct, object_id=blog.id) > > *It gave error,* > > ValueError: Cannot assign "<ContentType: post>": "Chapter.content_type" > must be a "ContentType" instance. > > *2. I tried* > > ct = > orm['contenttypes.ContentType'].objects.get_for_model(orm['blog.Post']) > chapter = orm.Chapter(rank=1, content_type=ct, object_id=blog.id) > > *It gave error,* > > AttributeError: 'Manager' object has no attribute 'get_for_model' > > *3. I tried* > > ct = orm['contenttypes.ContentType'].get(app_label="blog", model="Post") > > # I also tried setting model in the above get method to be lowercase. > > chapter = orm.Chapter(rank=1, content_type=ct, object_id=blog.id) > > *It gave error,* > > AttributeError: type object 'ContentType' has no attribute 'get' > > *BTW*, I am using *South 0.7.3.* > > Thanks again for helping. > > On Mon, Aug 8, 2011 at 10:25 AM, Tom Evans <tevans...@googlemail.com>wrote: > >> On Mon, Aug 8, 2011 at 3:06 PM, Chintan Tank <tankchin...@gmail.com> >> wrote: >> > (sorry for duplicate I have already posted on stackoverflow.com > >> > http://goo.gl/I7Jj6 ) >> > >> > I need to perform a datamigration of a model Answer in app Question. >> > In that script there is a dependency such that I need to create an >> > instance of a model Chapter which is in the app Journal. So, I coded >> > it as follows: >> > >> > def forwards(self, orm): >> > for answer_object in orm.Answer.objects.all(): >> > >> > #This Works. >> > blog, is_created = >> > orm['blog.Post'].objects.get_or_create(title=answer_object.answer[: >> > 100]) >> > blog.save() >> > >> > #This DOES NOT work >> > chapter, is_created = >> > orm['journal.Chapter'].objects.get_or_create(content_object=blog) >> > chapter.save() >> > #cleanup task, not relevant to this question below >> > answer_object.chapter_ptr = chapter >> > answer_object.save() >> > >> > >> > >> > But as expected this throws an error on " >> > orm['journal.Chapter'].objects.get_or_create(content_object=blog)" >> > saying that > django.core.exceptions.FieldError: Cannot resolve >> > keyword 'content_object' into field. >> > >> > This is presumably due to content_object being a GenericForeignKey so >> > some operations are not allowed. But I also tried other alternatives >> > for creating the "chapter" object like, >> > >> > chapter = orm['journal.Chapter'](content_object=blog) >> > ERROR > TypeError: 'content_object' is an invalid keyword argument for >> > this function >> > >> > and >> > >> > chapter = orm.journal.Chapter(content_object=blog) >> > ERROR > AttributeError: The model 'journal' from the app 'questions' >> > is not available in this migration. (Did you use orm.ModelName, not >> > orm['app.ModelName']?) >> > >> > So since my earlier approach was failing I tried a new tact. The model >> > whose instantiation was failing in my code above i.e. Chapter in the >> > Journal app, I decided to create a datamigration for that instead. I >> > also made sure to --freeze the models I am referring to in the >> > forwards definition. Now this should have been straight forward, I >> > would think. I have my forward code as follows - >> > >> > def forwards(self, orm): >> > >> > for answer_object in orm['questions.Answer'].objects.all(): >> > >> > #Works, AGAIN! >> > blog, is_created = >> > orm['blog.Post'].objects.get_or_create(title=answer_object.answer[: >> > 100]) >> > blog.save() >> > >> > # DOES NOT WORK, AGAIN! >> > chapter = orm.Chapter(rank=1, content_object=blog) >> > chapter.save() >> > >> > >> > I would have thought that now since I am creating instance of a model >> > (Chapter) which exists in the subject app (Journal) everything should >> > have worked out. But i am getting the same error > TypeError: >> > 'content_object' is an invalid keyword argument for this function. >> > >> > It fails at the same point, namely, "content_object". I will post >> > below the model definition if that might help. >> > >> > class Chapter(models.Model): >> > >> > rank = models.IntegerField() >> > >> > content_type = models.ForeignKey(ContentType) >> > object_id = models.PositiveIntegerField() >> > content_object = generic.GenericForeignKey() >> > >> > Also all the models being touched in these forwards methods, namely - >> > blog, chapter, questions; are fully defined in the 00n_*.py files >> > created by South's schemamigration. >> > >> >> content_object isn't a 'real' field, it is some magic applied to the >> ORM and your model. The real fields are object_id and content type, so >> use them directly. >> >> Use ContentType.objects.get_for_model() [1] to get the content type. >> >> [1] >> https://docs.djangoproject.com/en/1.3/ref/contrib/contenttypes/#django.contrib.contenttypes.models.ContentTypeManager.get_for_model >> >> Cheers >> >> Tom >> >> -- >> 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 >> django-users+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/django-users?hl=en. >> >> > > > -- > Thanks & Regards, > > Chintan Tank > Software Developer > School of Library & Information Science > Indiana University, Bloomington. > > http://www.cs.indiana.edu/~cdtank/ > -- Thanks & Regards, Chintan Tank Software Developer School of Library & Information Science Indiana University, Bloomington. http://www.cs.indiana.edu/~cdtank/ -- You received this message because you are subscribed to the Google Groups "Django users" group. 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