ValidationError message isn't helpful in tracking down the field that fails validation

[Steve Steiner <ssteinerX@…>]

raise exceptions.ValidationError(self.error_messagesinvalid?)
[Wed Jan 12 21:59:58 2011] [error] [client 10.177.133.202] ValidationError: [u'Enter a valid date/time in YYYY-MM-DD HH:MM[:ss[.uuuuuu]] format.']

If the error message contained the invalid data, and, especially the name of the field that was being validated, that would be way more helpful.

I'm going to go look for this in the source, but someone more familiar with this piece of code could probably make this change in pretty short order.

[Steve Steiner <ssteinerX@…>]

Sorry, the error is in:

File "/xxxxxxxxxxxxxxxxxxx/django/db/models/fields/init.py", line 710, in to_python

[Russell Keith-Magee]

A reasonable suggestion; not for 1.3, however, because we have hit feature freeze, and this would be a new feature.

Out of interest, the BaseValidator (on which the min/max value validators is based) already does this; but the min/max validation strings don't exploit the capability.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[ANUBHAV JOSHI]

Any design decision for this??

[ANUBHAV JOSHI]

I have looked into this and there are some changes from when the ticket was filed.

In DateTimeField in db/models/fields/__init__.py

default_error_messages = {
        'invalid': _("'%(value)s' value has an invalid format. It must be in "
                     "YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."),
        'invalid_date': _("'%(value)s' value has the correct format "
                          "(YYYY-MM-DD) but it is an invalid date."),
        'invalid_datetime': _("'%(value)s' value has the correct format "
                              "(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
                              "but it is an invalid date/time."),
    }

But in DateTimeField in django/forms/fields.py

default_error_messages = {
        'invalid': _('Enter a valid date/time.'),
    }

There have been a lot of changes in the source code from the time it was filed. So it seems that this is changed in db/models/fields/__init__.py which is the place where Steve mentions he found the problem.
But the component in the the ticket says Forms, in which the problem still exists as the errors from the forms still are not at all good if they just say Enter a valid date/time. I am not sure that how the forms got there errors earlier, probably from models itself, but atleast now it is not.

• In many of the form fields, the error messages are much better and self-explanatory but the above and in many places like DateField, TimeField, DateTimeField, URLField and maybe some more, I think we can make those better just like in the db/models/fields/__init__.py.
• I think we should make default_error_messages in forms and models similar. In models, every error message contains the faulty value but in forms, it does not. The description says to pass name of the field, but I think passing the faulty value just as in case of models would be much better.

So what I think that atleast we should improve errors in the form fields that I listed out above and other similar ones and also we can decide on the second point, i.e. whether we should pass the value onto the errors in the all form errors as is done in few so as to make it similar to that in models.

[Claude Paroz]

As for forms, I don't think we should change the error messages, as the field values and names are often obvious when the form is redisplayed with errors.

It would be nice if we could narrow the use cases targeted by this ticket (which is not forms IMHO).

[ANUBHAV JOSHI]

The error messages in forms.fields in Date and Time related field do not even mention what is the correct format.
Probably the errors earlier were gathered from models.fields, but now if date is wrong, we get only 'Enter a valid date/time.'

I think we should atleast update those messages to the previous state where they tell what is the correct format, i.e. specifying YYYY-MM-DD HH:MM[:ss[.uuuuuu]] for DateTimeField and other related or similar ones or else if someone enters wrong in forms, we only get: Enter valid date/time.

[Claude Paroz]

Maybe, but then please open a new ticket to not mix issues.

[ANUBHAV JOSHI]

IMO, I think what was asked by Steve, i.e. to include name is no more required as default_error_messages in db/models/field/__init__.py have changed and they are good.

Though the new form errors now are even less better than previous ones mostly in date/time or url fields. So I think we should close this ticket and open a new one for the improvements in those messages with what I suggested.
If we agree to this, then I would request one of the admins to close this so I'll open a new one with the suggested.
Thanks.

[Tim Graham]

I agree the original issue appears to be fixed.

Regarding forms, I think it's better if the developer includes help_text or a custom error message if they wants to include the accepted formats. Field.input_formats is something like [u'%Y-%m-%d', u'%m/%d/%Y', u'%m/%d/%y'] which most end users won't know how to interpret.