CODEWITHSUNDEEP
htmldjangodjango-modelsmodelform
kshubham07
kshubham07

Reputation: 391

HTML Select dropdown with dynamic list in Django ModelForm

In the view : I need to display a dropdown list of years starting from a fixed value (say 2005) to the current year. Now, this list, though dynamic, does not come from the database. Also, I want the list to expand as time goes by.

In the model : I want this field to be like an IntegerField(?) which saves values only from 2005 to, say, 3000, and throws a validation error otherwise.

What I could do - Make the dropdown as a ChoiceField in the View, and set up a validator for the model.

What I want - I want to use ModelForm in Django since this field, along with others in the form maps to the fields of my model. It means that I wont be defining fields in my Form, but only in the model. The question is, therefore, what should my approach be?

This I have tried so far-

class Member(models.Model):
    d = int(datetime.datetime.now().strftime("%Y"))
    ch = [(X,X) for X in range(2005,d)]
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    membership_type = models.IntegerField(validators=[validate_membership_type])
    batch = models.IntegerField(choices= ch)

This generates the form with desired select field but the values do not change. I replaced 'Years' by 'Minutes' to test it, and the range remains fixed with the upper limit as the number of minutes at the time of starting the server ,i.e., when the model gets created. I want this range to be determined by the view, i.e., when the form is loaded on the browser.

Upvotes: 1

Views: 2540

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599610

Firstly, this code does not belong in the model, but in the form.

Secondly, if you need things to be dynamic, they must go in the __init__ method, not at class level. So:

class MemberForm(forms.ModelForm):
    class Meta:
        model = Member
        fields = [..., 'batch', ...]

    def __init__(self, *args, **kwargs):
        super(MemberForm, self).__init__(*args, **kwargs)
        d = datetime.datetime.now().year
        ch = [(X,X) for X in range(2005, d)]
        self.fields['batch'].choices = ch

Upvotes: 1

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