How to access data when form.is_valid() is false

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When I have a valid Django form, I can access the data with form.cleaned_data. But how do I get at the data a user entered when the form is not valid i.e., form.is_valid is false.

I'm trying to access forms within a form set, so form.data seems to just give me a mess.

7 Answers

See http://docs.djangoproject.com/en/dev/ref/forms/validation/#ref-forms-validation

Secondly, once we have decided that the combined data in the two fields we are considering aren't valid, we must remember to remove them from the cleaned_data.

In fact, Django will currently completely wipe out the cleaned_data dictionary if there are any errors in the form. However, this behaviour may change in the future, so it's not a bad idea to clean up after yourself in the first place.

The original data is always available in request.POST.


A Comment suggests that the point is to do something that sounds like more sophisticated field-level validation.

Each field is given the unvalidated data, and either returns the valid data or raises an exception.

In each field, any kind of validation can be done on the original contents.

I ran into a similar problem using a formset. In my example, I wanted the user to select a 1st choice before a 2nd choice, but if the 1st choice hit another error, the 'select 1st choice before 2nd' error was also displayed.

To grab the 1st field's uncleaned data, I used this within the form field's clean method:

dirty_rc1 = self.data[self.prefix + '-reg_choice_1']

Then, I could test for the presence of data in that field:

if not dirty_rc1:
    raise ValidationError('Make a first choice before second')

Hope this helps!

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