Hi frantisek,
I've also ran into a number of problems with extra whitespace in forms.
Pretty annoying.
I also find settings pretty annoying. :) We were just talking on another
thread [1] about the possibility of packaging packaging django.forms as a
standalone package, but global settings are one of the main roadblocks to
doing that.
Here are a few more possible solutions:
1. Include some javascript on your page that .trim()s everything, maybe
onsubmit.
2. form = Form({k: v.strip() for k, v in request.POST.items()})
3. Use a custom form subclass that strips the incoming values in __init__
4. call strip() on model.save() or a pre_save signal.
[1] https://groups.google.com/d/msg/django-developers/WF3My-cZNtY/V0Z8QkQaOnAJ
Collin
On Tuesday, February 3, 2015 at 12:22:38 PM UTC-5, frantisek holop wrote:
>
> good day,
>
> a recent technical support incident conducted remotely and
> involving a lot of back and forth of "huh? but i have entered
> what you sent me" left me my head scratching.
>
> the reason turned out to be a trailing space in the username of
> the django admin loginform (thank god for nginx's "$request_body"
> log_format parameter).
>
> this of course sent me on an archeological journey into the lands
> of stackoverflow, blogs, and finally #6362 and this mailing list.
> it has been some 5 years now since the decision on that
> controversial ticket.
>
> i also went through the whole emotianal rollercoaster:
>
> how come, so many batteries are included, but when it comes to
> this essential POST best practice, i needed in every single
> webform i have ever made, and now i have to do it myself?
> error-prone and not DRY. especially for the admin login form,
> it is a usability issue.
>
> vs
>
> the BDFL is right, silently discarding user input is just wrong.
> just use a package like happyforms[1], or pick a stackoverflow
> answer and be done with it.
>
>
> but wait, then HTML is also wrong, because it silently folds all
> whitespace into 1 piece of space, we are all used to this. even
> if the user entered whitespace is saved, pushing it back onto the
> web will silently corrupt it (unless taken care of). i am not
> saying this requirement does not exist for someone, somewhere,
> but i have yet to see a site in the wild that needs this (hello,
> ascii art people). whitespace in fields was always reserved for
> government sites :)
>
>
> it seems to me that there is a vocal group (majority?) that would
> welcome a simple switch to make whitespace go away _now_, instead
> of waiting for that perfect solution lurking in the future along
> the lines of a generic normalize kwarg, or a flag on _every_
> {Char,Text}Field on the model or overriding form.fields
> attributes like required.
>
> apps that need to preserve the whitespace are the exception,
> not the rule, and that is why i would prefer not to start every
> project by overriding BaseForm._clean_fields[2].
>
> so i would like to present another idea for a possibe solution, a
> proposal i have not seen so far: to have a global setting like
> FORM_STRIP_FIELDS=True or some such and then roughly:
>
> diff --git a/django/forms/forms.py b/django/forms/forms.py
> index c9b8cf2..aab737a 100644
> --- a/django/forms/forms.py
> +++ b/django/forms/forms.py
> @@ -8,6 +8,7 @@ from collections import OrderedDict
> import copy
> import datetime
>
> +from django.conf import settings
> from django.core.exceptions import ValidationError, NON_FIELD_ERRORS
> from django.forms.fields import Field, FileField
> from django.forms.utils import flatatt, ErrorDict, ErrorList
> @@ -355,6 +356,8 @@ class BaseForm(object):
> if isinstance(field, FileField):
> initial = self.initial.get(name, field.initial)
> value = field.clean(value, initial)
> + elif isinstance(value, basestring) and
> settings.FORM_STRIP_FIELDS:
> + value = field.clean(value.strip())
> else:
> value = field.clean(value)
> self.cleaned_data[name] = value
>
> i know, it is a big hammer, but for me, it is like the timezone,
> or csrf, i'd like to just set it, and forget about it.
>
> -f
>
> [1] https://pypi.python.org/pypi/happyforms
> [2] http://chriskief.com/2012/12/21/trim-spaces-in-django-forms/
> --
> nobody can be exactly like me. even i have trouble doing so.
>
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