When you are creating a system from scratch, coming with a ideal and organized model is simple enough, but when you are trying to replicate a real world system/issue into your models, things get complicated.
By complicated I mean, almost every relationship is a M2M with intermediary fields, that's the issue I'm trying to solve using Django, real world documents, contracts, people. The main concern is making the CRUD web app easy for the user eyes. Django really made things difficult, specially because in our context the relationship direction doesn't matter, we want both forward and reverse fields when editing an object *First suggestion: give reverse relationships a common attribute for an easier way of getting them* This is the code I had to make to get only reverse relationships of a model, it is very ugly and not my proudest work, but it works(so far) #I'm sure there's a better way of doing this #This is the documented way of getting reverse fields, but it also gets ManyToOne rel with the through table of forward m2m rels, so we have to filter them reverse_fields = [f for f in opts.get_fields() if f.auto_created and not f. concrete] reverse_m2m = [f for f in reverse_fields if f.__class__.__name__ == 'ManyToManyRel' and f.on_delete == None and not getattr(model,f.field.name, False)] #Also filtering the ManyToOne rel with the through table of the reverse m2m rels, because we need to differentiate them from reverse ManyToOne with other models(not through) reverse_m2m_through = [f for f in reverse_fields if f.__class__.__name__ == 'ManyToOneRel' and f.related_model in [f.through for f in reverse_m2m if getattr(f,'through',False)]] forward_m2m = [f.remote_field for f in opts.get_fields() if not f.auto_created and f.many_to_many] #Filtering the ManyToOne rels with the through table of forwards m2m rels, same logic as above forward_m2m_through = [f for f in reverse_fields if f.__class__.__name__ == 'ManyToOneRel' and f.related_model in [f.through for f in forward_m2m if getattr(f,'through',False)]] reverse_fields_final = itertools.chain(reverse_m2m, [f for f in reverse_fields if f not in itertools.chain(reverse_m2m, reverse_m2m_through, forward_m2m, forward_m2m_through)]) *Second suggestion: following the first suggestion, give support to edit reverse rels in forms, and m2m with through tables* An optional argument to ModelForm to also catch reverse relationships, using a specific form field for it, example : ReverseModelChoiceField, etc..., this can be done with just a simple changes to their forward counterpart classes And, the most complex suggestion probably, is to add a form field to deal with M2M with through tables that contain intermediary fields, this can be done with a widget that is a table with inputs for cells, plus also work with reverse as suggested above, so I'm suggesting the creation of the 5 following model form fields : 1. ReverseModelChoiceField 2. ReverseMultipleModelChoiceField 3. ReverseManyToManyWithIntermediaryField (I'm sure there's a better name) 4. ManyToManyWithIntermediaryField -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at https://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/4b82d7d5-3a8d-4130-97b6-dff5423f9372%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
