以表单（django）传递数据库值

Question

My form.py :

class BannerForm(forms.ModelForm):
    name = forms.CharField(max_length=32)
    #Affiliazione = forms.CharField(disabled = True, initial='red') #in original question
    #affiliation = forms.ModelChoiceField(Affiliation.objects.all(),
    #widget=forms.HiddenInput(), initial=Affiliation.objects.get(id=1))  #in original question
    Affiliazione = forms.CharField(disabled = True, required=False) #added after first answer
    affiliation = forms.ModelChoiceField(Affiliation.objects.all(),
    widget=forms.HiddenInput()) #added after first answer

The 'Affiliazione' field display 'red' but it isn't saved because Disabled controls cannot be successful . The 'affiliation' field actually pass the data but is hidden. They together give what I want (a disabled field that pass data so the user can see the value but can't change it).

The problem is I don't like to hardcode that values ('red' and 'id=1'). I have the 'Options' class in models where I choose the value to pass but I don't know how... I think it's a silly question, sorry, but someone can help me?

My models.py :

class Options(models.Model):
    new_affiliation = models.ForeignKey('Affiliation')

class Affiliation(models.Model):
    name = models.CharField(max_length=32, unique=True)
    def __str__(self):
        return self.name

class Banner(models.Model):
    name = models.CharField(max_length=32, unique=True)
    affiliation = models.ForeignKey(Affiliation)

Edit. My View.py :

def add_banner(request):
    # A HTTP POST?
    if request.method == 'POST':
        form = BannerForm(request.POST)
        print('form is post') #control
        # Have we been provided with a valid form?
        if form.is_valid():
            print('form is valid') #control
            # Save the new banner to the database.
            banner = form.save(commit=False)
            #some irrilevant code here
            form.save(commit=True)
            print('form salvato') #control
            # Now call the homepage() view.
            # The user will be shown the homepage.
            return homepage(request)
        else:
            # The supplied form contained errors - just print them to the terminal
            print (form.errors)
    else:
        # If the request was not a POST, display the form to enter details
        #form = BannerForm(request.POST) #in original question
        #initial_value = 'red' #added after first answer
        #init = Affiliation.objects.get(id=1) #added after first answer
        form = BannerForm(request.POST or None, initial={
        'affiliation': Campaign_Options.new_regent_affiliation}) #added after first answer
    # Bad form (or form details), no form supplied...
    # Render the form with error messages (if any).
    print ('fine')
    return render(request, 'core/add_banner.html', {'form': form})

My add_banner.html :

  {% csrf_token %}
  {% for hidden in form.hidden_fields %}
  {{ hidden }}
  {% endfor %}

  {% for field in form.visible_fields %}
    {{ field.errors }}
    {{ field.label }}
    {{ field }}
    {{ field.help_text }}
    <br />
  {% endfor %}

Answer 1

Even if I don't quite get the intention of your form, but for the sake of answering your question, you could pass the initial value from your views when you initialize the form, this will make the value flexible:

def your_view(request):
    # get the string for affilizione by applying your logic here
    # initial_value = 'red'
    form = BannerForm(request.POST or None, initial={'Affiliazione': initial_value})