Question

if request.method == 'POST':
    try:
        form = ExampleForm(request.POST,
                               instance=Example.objects.get(user=request.user))
    except:
        form = ExampleForm(request.POST)
    if form.is_valid():
        m = form.save(commit=False)
        is_ok = request.POST.get('is_ok')
        m.is_ok = is_ok
        m.user = request.user
        m.save()

How to add field is_ok to instance=Example.objects.get(user=request.user)

Note: I can not add this field to the model forms.

If I change existing data, my is_ok value changes to default

EDIT:

<input type="checkbox" disabled="disabled" checked="checked" name="is_ok" id="id_is_ok"/>

If this input is disabled, my is_ok = request.POST.get('is_ok') = None

Answer 1

You really should do this in the declaration of your ExampleForm class. I assume the class looks something like this

from your_app.models import ExampleModel
from django.forms import ModelForm

class ExampleForm(ModelForm):
    class Meta:
        model = ExampleModel

You just need to declare the field on the form. Something like –

class ExampleForm(ModelForm)
    is_ok = forms.BooleanField()
    class Meta:
        model = ExampleModel

The form class will now handle the creation of the input element for the is_ok field, just as it does for all the other fields, but it will override the settings on the Model – it won’t be disabled any more (see the docs for more info).