Change a Django form field to a hidden field

I have a Django form with a RegexField, which is very similar to a normal text input field.

In my view, under certain conditions I want to hide it from the user, and trying to keep the form as similar as possible. What's the best way to turn this field into a HiddenInput field?

I know I can set attributes on the field with:

form['fieldname'].field.widget.attr['readonly'] = 'readonly'

And I can set the desired initial value with:

form.initial['fieldname'] = 'mydesiredvalue'

However, that won't change the form of the widget.

What's the best / most "django-y" / least "hacky" way to make this field a <input type="hidden"> field?

This may also be useful: {{ form.field.as_hidden }}

If you have a custom template and view you may exclude the field and use {{ modelform.instance.field }} to get the value.

also you may prefer to use in the view:

form.fields['field_name'].widget = forms.HiddenInput()

but I'm not sure it will protect save method on post.

Hope it helps.

an option that worked for me, define the field in the original form as:

forms.CharField(widget = forms.HiddenInput(), required = False)

then when you override it in the new Class it will keep it's place.

Firstly, if you don't want the user to modify the data, then it seems cleaner to simply exclude the field. Including it as a hidden field just adds more data to send over the wire and invites a malicious user to modify it when you don't want them to. If you do have a good reason to include the field but hide it, you can pass a keyword arg to the modelform's constructor. Something like this perhaps:

class MyModelForm(forms.ModelForm):
    class Meta:
        model = MyModel
    def __init__(self, *args, **kwargs):
        from django.forms.widgets import HiddenInput
        hide_condition = kwargs.pop('hide_condition',None)
        super(MyModelForm, self).__init__(*args, **kwargs)
        if hide_condition:
            self.fields['fieldname'].widget = HiddenInput()
            # or alternately:  del self.fields['fieldname']  to remove it from the form altogether.

Then in your view:

form = MyModelForm(hide_condition=True)

I prefer this approach to modifying the modelform's internals in the view, but it's a matter of taste.