Using field values from a ForeignKeyed object for ModelChoiceFields - django

Question

My friends and I play a spreadsheet-based sports picking game which is very tedious to make changes to. I've wanted to learn Django for a while so I've been working on creating it as a webapp. Here are the models I'm working with:
class Sheet(models.Model):
user = models.ForeignKey(User)
... other stuff
class Game(models.Model):
home_team = models.CharField(max_length=100, default='---')
away_team = models.CharField(max_length=100, default='---')
... other stuff
class Pick(models.Model):
sheet = models.ForeignKey(Sheet)
game = models.ForeignKey(Game)
HOME = 'H'
AWAY = 'A'
PICK_TEAM_CHOICES = (
(HOME, 'Home'),
(AWAY, 'Away'),
)
pick_team = models.CharField(max_length=4,
choices=PICK_TEAM_CHOICES,
default=HOME)
... other stuff
Right now, I'm trying to nail down a simple way to display the following form with information from a foreign keyed model instead of the pick_team default choices. The game is hidden because it's paired with the generated PickForm via use of the initial functionality in the view.
class PickForm(ModelForm):
class Meta:
model = Pick
widgets = {'game': forms.HiddenInput()}
fields = ['sheet','game','amount','pick_type','pick_team']
def __init__(self, *args, **kwargs):
game = kwargs['initial']['game']
super(PickForm, self).__init__(*args, **kwargs)
self.fields['pick_team']=forms.ModelChoiceField([game.away_team,game.home_team])
From what I can tell, the ModelChoiceField expects a queryset- so when I provide a list or a tuple, I get a 'list' object has no attribute 'iterator' error. Knowing this now, how can I display the Game fields home_team and away_team in the pick_team dropdown on the template? Currently it defaults to 'Home' and 'Away'.
I know this is a common question at the core- how to display ForeignKeyed information in a dropdown, however all the answers I've found are fine with providing a queryset to ModelChoiceField, because they're typically trying to list a field from every object (or some filtered subset). In this case, I only want to list 2 fields, and only from one object.
I tried returning a queryset consisting of the Game object already present in kwargs, but it just displays the game's str() method in the dropdown, and attempting to refine the queryset with the relevant field names isn't working either.
EDIT: I realized that actually using the home_team and away_team values from the Game object would require extra processing on saving the Pick, or possibly be harder than that. Is there any way to do this sort of aliasing in the template alone? Similar to how with choice fields I can use get_pick_team_display to show a nicer looking display value ('Home', 'Away') instead of the vague 'H' or 'A'.
EDIT2: View code
class GameDetail(DetailView):
#model = Game
template_name = 'app/games.html'
context_object_name = 'game_detail'
def get_object(self):
game = get_object_or_404(...object filtering)
return game
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
try:
pick = Pick.objects.get(game=context['game_detail'],
....other stuff)
context['pickform'] = PickForm(initial={'game':context['game_detail'],
.... other stuff
except Pick.DoesNotExist:
#pick = none
context['pickform'] = PickForm(initial={'game':context['game_detail'],
})
return context
def post(self, request, *args, **kwargs):
form = PickForm(request.POST)
if form.is_valid():
....process form

Answer 1

This is a quickfix approach. In your __init__, instead of reassigning pick_team field, just redefine its options as follows:
self.fields['pick_team'].choices = (
('H', game.home_team),
('A', game.away_team),
)