Add example to Form.changed_data

[Matthew Pava]

​https://docs.djangoproject.com/en/2.2/ref/forms/api/#django.forms.Form.changed_data

The documentation has a nice example for Form.has_changed() that shows the result as True or False. I would like to see another such simple example in the documentation for Form.changed_data that actually shows what the results of Form.changed_data are.

[Mariusz Felisiak]

I think we can even add two more lines to the current example.

[Bruno Furtado]

Do you think that just add the output from the snippet is enough?

    >>> f = ContactForm(request.POST, initial=data)
    >>> if f.has_changed():
    ...     print("The following fields changed: %s" % ", ".join(f.changed_data))
    The following fields changed: subject, message

Or something like this is better?

    >>> f = ContactForm(request.POST, initial=data)
    >>> if f.has_changed():
    >>>     print(f.changed_data)
    ['subject', 'message']

Let me know so I can submit a patch for it. Thank you.

[Carlton Gibson]

Hi Bruno. From Mariusz' comment, it looks like he intends that you just add the extra lines:

I guess:

>>> f.changed_data
['subject', 'message']

Easiest way forward is if you open a PR. (It's better to comment on actual code.)

[Mariusz Felisiak]

Yeah, exactly 👍.

Replying to Carlton Gibson:

Hi Bruno. From Mariusz' comment, it looks like he intends that you just add the extra lines:

I guess:

>>> f.changed_data
['subject', 'message']

Easiest way forward is if you open a PR. (It's better to comment on actual code.)

[Bruno Furtado]

Hi Carlton,
Thank you for clarify it. I agree, I opened the PR let's keep discussing there then.: ​https://github.com/django/django/pull/11186

Replying to Carlton Gibson:

Hi Bruno. From Mariusz' comment, it looks like he intends that you just add the extra lines:

I guess:

>>> f.changed_data
['subject', 'message']

Easiest way forward is if you open a PR. (It's better to comment on actual code.)

[Mariusz Felisiak]

​PR

[Mariusz Felisiak <felisiak.mariusz@…>]

In 571ab44:

Fixed #30321 -- Added example of changed_data to forms docs.

[Mariusz Felisiak <felisiak.mariusz@…>]

In bfe27929:

[2.2.x] Fixed #30321 -- Added example of changed_data to forms docs.

Backport of 571ab44e8a8936014c22e7eebe4948d9611fd7ce from master