Re: Writing a validator to look for cookie data

Well, first be careful, Any runs the last validator in the list first.
 Also, hm... Any reads the not_empty value of its sub-validators and
uses that, and if any of the validators accept empty values then it
shortcuts the process.  Hrm.  I think All has been revised to be a
little more sensible (the is_empty method on All always returns
false).  Yeah... okay, I changed that in trunk so Any and All work the
same.

On Thu, Mar 12, 2009 at 8:58 PM, Matthew Wilson <[email protected]> wrote:
> Thanks for the tip.
>
> Any idea why Any() doesn't seem to run in my code when no value exists?
>
> Matt
>
> On Thu, Mar 12, 2009 at 2:18 PM, Ian Bicking <[email protected]> wrote:
>> For something like this, I usually handle this stuff with unencoded
>> values.  That is, I don't hit the validator at all when rendering the
>> form.  I'd just get the defaults like:
>>
>> if req.method == 'POST':
>>    defaults = req.POST.mixed()
>>    force_defaults = True
>> else:
>>    defaults = {}
>>    force_defaults = False
>> defaults.update(cgi.parse_qs(req.cookies.get('form_defaults', '')))
>> defaults.update(req.GET.mixed())
>> body = htmlfill.render(form, defaults, force_defaults=force_defaults)
>>
>> If you want to use a validator, I'd use it on the line "defaults={}",
>> and replace that with something that grabs the encoded values from
>> some existing model, then runs "defaults =
>> schema.from_python(values)".
>>
>> On Thu, Mar 12, 2009 at 12:39 PM, Matthew Wilson <[email protected]> wrote:
>>> I store fields from form submissions into a cookie, and then when a
>>> user hits a form, I prepopulate the form with that data.
>>>
>>> I want to write a validator that first tries to get values from the
>>> query string, and if that is None, then the validator should check the
>>> cookie.
>>>
>>> Here is what I have:
>>>
>>> class LookInCookie(FancyValidator):
>>>    """
>>>    Retrieves something from the cookie.  Depends on a state with an
>>>    attribute named 'simple_cookie'.
>>>    """
>>>
>>>    def __init__(self, k, d=None):
>>>        """
>>>        Return k from the cookie, or d if it isn't there.
>>>        """
>>>        self.k, self.d = k, d
>>>
>>>    def to_python(self, value, state=None):
>>>
>>>        log.debug("Inside LookInCookie.to_python with locals: %s"
>>>            % locals())
>>>
>>>        if hasattr(state, 'simple_cookie') \
>>>        and state.simple_cookie.has_key(self.k):
>>>
>>>            return state.simple_cookie[self.k]
>>>
>>>        else:
>>>            return self.d
>>>
>>> Then I tried to combine this validator with Any() like this:
>>>
>>>>>> from turbogears.util import Bunch
>>>>>> s = Bunch(simple_cookie={'city':1})
>>>>>> v = Any(LookInCookie('city'), validators.Int())
>>>>>> v.to_python('99', s)
>>> 99
>>>>>> v.to_python('abc', s)
>>> 1
>>>
>>> So far, so good!  First, the Int validator runs, then when Int fails,
>>> I get the value from the cookie s.
>>>
>>> However, here's where things fall apart.  When there is no value
>>> passed in, nothing comes back out!
>>>
>>>>>> v.to_python('', s)
>>>>>> v.to_python(None, s)
>>>
>>>
>>> How do I force validators to run even when the value is missing?
>>>
>>> More generally, is there a better solution to what I'm trying to do?
>>>
>>> --
>>> Matthew Wilson
>>> [email protected]
>>> http://tplus1.com
>>>
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>>
>>
>>
>> --
>> Ian Bicking  |  http://blog.ianbicking.org
>>
>
>
>
> --
> Matthew Wilson
> [email protected]
> http://tplus1.com
>



-- 
Ian Bicking  |  http://blog.ianbicking.org

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Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are
powering Web 2.0 with engaging, cross-platform capabilities. Quickly and
easily build your RIAs with Flex Builder, the Eclipse(TM)based development
software that enables intelligent coding and step-through debugging.
Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com
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