[Python-modules-team] Bug#637658: validators.Required() on IntegerField does not allow a value of "0"

[Enrico Zini]

Package: python-wtforms
Version: 0.6.2-1
Severity: normal

Hello,

thank you for packaging wtforms.

I just found out, much to my frustration, that the Required validator
will not accept values of "0" in IntegerFields: the check it uses is a
simple "if not field.data" which obviously fails if field.data is 0.

Oddly, as a result the way to validate a required integer value is NOT
to use any validator. Since the IntegerField will call int() on any
value it gets (including the empty string), its default behavious is
to always require a value.

I did not find a way to have a "nullable" IntegerField that
accepts/returns integer values or None, which is what I would expect to
be the behaviour of IntegerField without a Required validator.

To summarise the behaviour I would expect:

  # Integer field that can be left blank, returning either an int() or
  # None
  age = wtf.IntegerField("Age")

  # Integer field that requires a value which can be any number,
  # including 0, and always returns an int()
  age = wtf.IntegerField("Age", wtf.validators.Required())

To summarise the behaviour I currently observe:

  # Integer field that requires a value which can be any number,
  # including 0, and always returns an int()
  age = wtf.IntegerField("Age")

  # Integer field that requires a value which can be any number,
  # EXCLUDING 0, and always returns an int()
  age = wtf.IntegerField("Age", wtf.validators.Required())


Ciao,

Enrico

-- System Information:
Debian Release: wheezy/sid
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.0.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages python-wtforms depends on:
ii  python                        2.6.7-2    interactive high-level object-orie
ii  python-support                1.0.14     automated rebuilding support for P

Versions of packages python-wtforms recommends:
ii  libjs-jquery                  1.6.2-1    JavaScript library for dynamic web
ii  python-dateutil               1.4.1-4    powerful extensions to the standar

Versions of packages python-wtforms suggests:
ii  python-django                 1.3-2      High-level Python web development 
ii  python-sqlalchemy             0.6.8-1    SQL toolkit and Object Relational 

-- no debconf information