Hi Gabriel, Yes, the hope is to make the situation better and more standard. Here's some of the status: https://code.djangoproject.com/ticket/24317 - real reverse fields. https://code.djangoproject.com/ticket/897 - real reverse many to many fields https://code.djangoproject.com/ticket/12203 - many to many with through tables
Also, filtering fields on the .multiple attribute might help you out. Not sure though. If it isn't, maybe open a pull request with a proposal for an attribute that would work for you? Quoting the advice from the first ticket: - Find places where field.remote_field responds to different API than Field. - Fix these one at a time while trying to have backwards compat, even if the API isn't public. - In addition, simplifications to the APIs are welcome, as is a high level documentation of how related fields actually work. - We need to try to keep backwards compat as many projects are forced to use the private APIs. - But most of all, do small incremental changes. As far as your specific use-case goes, "a widget that is a table with inputs for cells". The closest thing Django has is an "inline formset" (though not actually a form field) which is designed exactly for reverse relationships. You would say: ThroughFormSet = inlineformset_factory(MainModel, ThroughModel) https://docs.djangoproject.com/en/1.11/topics/forms/modelforms/#inline-formsets (Or in the admin, you just use an inline which uses an inlineformset under the hood.) Collin On Thu, Mar 30, 2017 at 3:30 PM, Gabriel Canto <ppgab.m...@gmail.com> wrote: > 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. 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