How to restrict form validation for users under 18 years of age in Django

Question

I have a form that allows users to update their birthday on their profile. I only want the form to validate if the user is at least 18 years of age. Here's what I've tried:

models.py

class Profile(models.Model):
    birthday = models.DateField()

forms.py

from django import forms
from datetime import date
from .models import Profile

class ProfileUpdateForm(forms.ModelForm):
    birthday = forms.DateField(widget=forms.DateInput(attrs={'type': 'date'}))

    def clean_birthday(self):
        dob = self.cleaned_data['birthday']
        age = (date.today() - dob).days / 365
        if age < 18:
            raise forms.ValidationError('You must be at least 18 years old')
        return dob

    class Meta:
        model = Profile
        fields = ('birthday',)

views.py

@login_required
def update_my_profile_view(request):
    profile = Profile.objects.get(user=request.user)

    if request.method == 'POST':
        form = ProfileUpdateForm(request.POST or None, instance=profile)
        if form.is_valid():
            form.save()
            return redirect('users:my_profile')
    else:
        form = ProfileUpdateForm()

    context = {
        'form': form,
    }

    return render(request, 'users/my_profile.html', context)

At the moment if I enter a date which is less than 18 years from the current day the date is simply not displayed. What I want instead is for the form to become invalid and show the user an error. How can I achieve this please?

Answer 1

because you didn't handle when form.is_valid() is false. you have to handle when form is invalid.

    ...

    if form.is_valid():
        form.save()
        return redirect('users:my_profile')
    context = {'form': form,}
    return render(request, 'users/my_profile.html', context)

    ...

why don't you try Class based view(CBV)? your update_my_profile_view is very typical code and Class based view will solve your problem more elegantly.

Answer 2

I realised the problem was because my form was inside a modal, and so the modal closed every time the form was submitted which made it look like the form was valid. The fix was to include this script tag below the form:

<script>
    $(document).ready(function() {
        {% if form.errors %}
            $("#my_modal").modal("show");
        {% endif %}
    });
</script>