On 04/19/2011 01:47 AM, Ivan Sagalaev wrote: > OK, may be not reverse OneToOne… What I mean is that although it seems > natural to treat all relations equally they are actually used for > different use cases where different defaults make sense. For example: > > - Reverse many-to-one (topic.article_set) access is used to access a > (limited) list of children which is expected to behave as any other list > of such objects and hence should use the default manager. > > - Direct one-to-one or many-to-one (article.topic or profile.user) > access is used to access a parent object and in most real cases it > doesn't make sense if it's absent for example. Usually you're just > dealing with a "deleted" child accessing its "deleted" parent which is > OK. In this case it makes sense to use a pure manager to build the > relation. > > As for reverse one-to-one I'm really not sure because I can't recall any > real example to lay upon. Speaking about documentation simplicity (which > directly influences sanity of its readers) it can be made as simple as > that: > > - pure manager is used whenever there is a clear child-parent realation > (direct OneToOne and ForeignKey access) > - all other relations use default managers > - explicit use_for_related_fields overrides default behavior > > What do you think?
I do find this pretty convincing. I don't see a good reason why a default manager should not be used by default for many-related access. In other words, I think the current behavior is probably better default behavior more of the time than the documented behavior would be. So I guess I've changed my position. I'm leaning towards fixing the docs to match what we currently do - and I'm also feeling more and more like the "use_for_related_fields" Manager class attribute is an ugly hack, and open to looking at patches to replace it with per-relation override of the default manager-selection. Carl -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
