Question

Say I have a model like:

class Team(models.Model):
    name = models.CharField(max_length=20)

class Game(models.Model):
    title = models.CharField(ma_length=20)
    home_team = models.ForeignKey(Team)
    away_team = models.ForeignKey(Team)

Then in my view I have:

def manage_games(request):
     GameFormSet = modelformset_factory(Game, extra=1)
     game_forms = GameFormSet(request.POST or None,
                                 queryset=Game.objects.all())
     if request.method == "POST":
         if game_forms.is_valid():
            game_forms.save()
            game_forms = GameFormSet(queryset=Game.objects.all())                 

     return render(request, "admin_dashboard/manage_games.html", locals())

This works okay except that I’d like to be able to turn the home_team and away_team into CharFields (rather than the dropdown it currently is) while also keeping them separate models. How can I add an inline model formset into a model formset to make this possible?

Answer 1

An inlinemodelformset wouldn’t work because Game has the foreignkeys Team.

An inlinemodelformset can show a list of forms for models which are connected to another via a ForeignKey. For example if A.b is an FK to B, then it is possible to make an inlinemodelformset of A for B.

However, you could still add a couple of fields to change the home/away team names:

from django import forms

from models import Team, Game    


class GameUpdateForm(forms.ModelForm):
    home_team_name = forms.CharField(max_length=20)
    away_team_name = forms.CharField(max_length=20)

    def save(self):
        obj = super(GameForm, self).save()

        if not obj.home_team_id:
            obj.home_team = Team()
        obj.home_team.name = self.cleaned_data.get('home_team_name')
        obj.home_team.save()

        if not obj.away_team_id:
            obj.away_team = Team()
        obj.away_team.name = self.cleaned_data.get('away_team_name')
        obj.away_team.save()

        return obj
    class Meta:
        model = Game
        exclude = ('home_team', 'away_team')

And make the modelformset use it:

GameFormSet = modelformset_factory(Game, form=GameForm, extra=1)

You might also want to add CharField autocompletion.