Error in example code in django.forms.Form.clean()¶

[richard.kellner@…]

In Documentation version: development explanation of Cleaning and validating fields (​https://docs.djangoproject.com/en/dev/ref/forms/validation/#cleaning-and-validating-fields-that-depend-on-each-other) that depend on each other there is and error. Code in the sample would thow an exeptoion: TypeError: argument of type 'NoneType' is not iterable because function does not return anything back. Documentation in 1.6 is correct and does not have this error. To resolve add return statement at the end of both function in example:

# Always return the full collection of cleaned data.
return cleaned_data

[Baptiste Mispelon]

Hi,

The documentation is correct: this is a new feature in the development version of Django (soon-to-be 1.7), as described by the note under the example:

In previous versions of Django, form.clean() was required to return a dictionary of cleaned_data. This method may still return a dictionary of data to be used, but it’s no longer required.

[Carsten Fuchs]

Replying to bmispelon:

Hi,

The documentation is correct: this is a new feature in the development version of Django (soon-to-be 1.7), as described by the note under the example:

In previous versions of Django, form.clean() was required to return a dictionary of cleaned_data. This method may still return a dictionary of data to be used, but it’s no longer required.

This however (referring to ​this example code), is inconsistent with the example code's statement

cleaned_data = super(ContactForm, self).clean()

about which a subsequent paragraph says:

Note that the call to super(ContactForm, self).clean() in the example code ensures that any validation logic in parent classes is maintained.

That is, if the clean() method of the parent class is coded like the example code for the child, the example code won't work.

[Tim Graham <timograham@…>]

In 80855a4:

Fixed #21894 -- Corrected a form.clean() example in case a superclass doesn't return data.

[Tim Graham <timograham@…>]

In 6861c20:

[1.8.x] Fixed #21894 -- Corrected a form.clean() example in case a superclass doesn't return data.

Backport of 80855a4b3787bace050a8b4a2b80f79306e69812 from master

[Tim Graham <timograham@…>]

In 55ed23fd:

[1.9.x] Fixed #21894 -- Corrected a form.clean() example in case a superclass doesn't return data.

Backport of 80855a4b3787bace050a8b4a2b80f79306e69812 from master