Django modelform NOT required field

Question

I have a form like this:

class My_Form(ModelForm):
    class Meta:
        model = My_Class
        fields = ('first_name', 'last_name' , 'address')

How can I set the address field as optional?

What does the model look like? – Ngenator Apr 25 '13 at 04:08 — Ngenator, Apr 25 '13 at 04:08

score 129 · Answer 1 · answered May 22 '15 at 18:54

129

class My_Form(forms.ModelForm):
    class Meta:
        model = My_Class
        fields = ('first_name', 'last_name' , 'address')

    def __init__(self, *args, **kwargs):
        super(My_Form, self).__init__(*args, **kwargs)
        self.fields['address'].required = False

answered May 22 '15 at 18:54

madzohan

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Altough the answer of akshar looks better, this method prevents you have to do stuff to set stuff like help_text and label. – Blackeagle52 Nov 24 '15 at 09:39
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This method is especially helpful in dealing with fields which are defined as FKs at model level. By akshar's method, one would have to set the `queryset` attribute. – PritishC Jan 22 '16 at 09:55

score 115 · Accepted Answer · edited Aug 14 '20 at 07:36

115

Guess your model is like this:

class My_Class(models.Model):

    address = models.CharField()

Your form for Django version < 1.8:

class My_Form(ModelForm):

    address = forms.CharField(required=False)

    class Meta:
        model = My_Class
        fields = ('first_name', 'last_name' , 'address')

Your form for Django version > 1.8:

class My_Form(ModelForm):

    address = forms.CharField(blank=True)

    class Meta:
        model = My_Class
        fields = ('first_name', 'last_name' , 'address')

edited Aug 14 '20 at 07:36

aronadaal

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answered Apr 25 '13 at 05:27

Akshar Raaj

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What about foreign key field? – digz6666 Oct 17 '13 at 04:14
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Use ModelChoiceField. So, if field definitions is `abc=models.ForeignKey(Abc)`, you can write `abc = forms.ModelChoiceField(queryset=Abc.objects.all(), required=False)` – Akshar Raaj Oct 17 '13 at 09:33
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Make sure that forms is imported if you weren't using it before: `from django import forms` – Justin McCandless Oct 30 '13 at 04:11
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Are you sure Django > 1.8 is supposed to accept `blank=True`? The docs say otherwise and my code doesn't like it, they say I should use `required=False`. Did you get your signs inverted? – Luca Bezerra Nov 27 '20 at 21:03

Diego Magalhães · Answer 3 · 2021-06-18T19:55:24.777

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field = models.CharField(max_length=9, default='', blank=True)

Just add blank=True in your model field and it won't be required when you're using modelforms.

"If the model field has blank=True, then required is set to False on the form field. Otherwise, required=True."

source: https://docs.djangoproject.com/en/3.1/topics/forms/modelforms/#field-types

edited Jun 18 '21 at 19:55

answered Mar 26 '19 at 12:00

Diego Magalhães

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Should be noted that if you are submitting forms manually as in `MyForm(form_data).is_valid()`, then the field must not be referenced in `form_data`. If it is included, but sent to a blank or None value, it seems it can still trigger the validation error. – Adam Starrh Jun 18 '21 at 17:11

score 8 · Answer 4 · edited Mar 26 '19 at 03:31

8

You would have to add:

address = forms.CharField(required=False)

edited Mar 26 '19 at 03:31

Transformer

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answered Aug 07 '14 at 16:42

Atma

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The blank and null attributes are not used for ModelForms – Fernando Ferreira Jun 15 '15 at 04:23
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this should be in the _model_ field, not the form field. `null=True, blank=True` will cause the ModelForm field to be `required=False` – Anentropic Mar 23 '17 at 17:29

score 6 · Answer 5 · edited Nov 28 '21 at 22:55

Solution: use both blank=True, null=True.

my_field = models.PositiveIntegerField(blank=True, null=True)

Explanation:

If you use null=True

my_field = models.PositiveIntegerField(null=True)

then my_field is required, with * next to it in the form and you can't submit the empty value.

If you use blank=True

my_field = models.PositiveIntegerField(blank=True)

then my_field is not required, there won't be a * next to it in the form and you can't submit the value. But it will get null field not allowed.

Note: marking as not required and allowing null fields are two different things.

Pro Tip: Read the error more carefully than documentation.

This answer works for fields that are not CharField or TextField. For these you do not want both null and blank because then there are multiple representations of empty. — mattm, Jul 09 '21 at 22:36

score 5 · Answer 6 · edited Nov 28 '21 at 22:52

@Anentropic's solution from the comment on @Atma's answer worked for me. And I think it's the best one too.

His comment:

null=True, blank=True will cause the ModelForm field to be required=False

I just set it on my ManyToMany field in my UserProfile class and it worked flawlessly.

My UserProfile class now looks like this (notice the friends field):

class UserProfile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    friends = models.ManyToManyField('self', null=True, blank=True)

I also think that this is the most beautiful solution since you do the same thing, put null and blank to True, weather you have a simple char field or, like I have, ManyToMany field.

for `ManyToManyField`, `blank=True` is sufficient. – Adam Starrh Jun 29 '21 at 17:16 — Adam Starrh, Jun 29 '21 at 17:16

score 0 · Answer 7 · answered Sep 05 '19 at 10:15

The above answers are correct; nevertheless due note that setting null=True on a ManyToManyField has no effect at the database level and will raise the following warning when migrating:

(fields.W340) null has no effect on ManyToManyField.

A good answer to this is explained in this other thread.

Django modelform NOT required field

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