In my opinion, you have mainly two options to bypass None value check that
formatter function in DAL does:
option 1 : store None in database, delete formatter from validator, use
represent in table field (I prefer this approach)
class IS_ELAPSED_TIME(object):
def __init__(self,error_message='Must be MM:SS.hh or MMSShh (with no
punctuation)'):
self.error_message=error_message
def __call__(self,value):
try:
if value and value.upper() != 'NT':
res = hms_to_int(value)
else:
res = None
return (res,None)
except:
return (value,self.error_message)
Field('est', 'string', requires=IS_ELAPSED_TIME(), represent=lambda value,
row:int_to_hms(value) if value else "NT")
option 2: store 'NT' in database in place of None
class IS_ELAPSED_TIME(object):
def __init__(self,error_message='Must be MM:SS.hh or MMSShh (with no
punctuation)'):
self.error_message=error_message
def __call__(self,value):
try:
if value and value.upper() != 'NT':
res = hms_to_int(value)
else:
res = 'NT'
return (res,None)
except:
return (value,self.error_message)
def formatter(self,value):
if value != 'NT':
rtn = int_to_hms(value)
else:
rtn = 'Elapsed Standard Time not available'
return rtn
Field('est', 'string', requires=IS_ELAPSED_TIME())
Il giorno venerdì 26 ottobre 2012 04:13:55 UTC+2, Joe Barnhart ha scritto:
>
> I do manage the "None" value in my formatter, Paulo.
>
> But it never gets called because the built-in code of the Field class
> tests the value for None and then exits before calling my formatter. So it
> doesn't matter that my formatter can handle None -- it is never called.
>
> That's why I posted the change to the Field class in the first message of
> this thread.
>
> -- Joe B.
>
> On Thursday, October 25, 2012 5:53:43 PM UTC-7, Paolo Caruccio wrote:
>>
>> Why don't you manage None values in int_to_hms function?
>>
>>
>> Il giorno giovedì 25 ottobre 2012 03:20:29 UTC+2, Joe Barnhart ha scritto:
>>>>>>
>>>>>> I have an application where I expect "None" items in my database and
>>>>>> I want to format them to "NT". It is an app that uses time standards,
>>>>>> and
>>>>>> if there is no standard present I expect a "None" in the database which
>>>>>> translates to a field of "No Time" or "NT".
>>>>>>
>>>>>> The problem is that the current implementation of formatter in the
>>>>>> Field class tests the value for "None" and escapes before the formatter
>>>>>> is
>>>>>> called.
>>>>>>
>>>>>> I can see why this behavior might be expected in a lot of cases, but
>>>>>> it seems extreme to deny the ability to format "None" into a more
>>>>>> pleasing
>>>>>> form for those applications that could benefit from it. Here is the
>>>>>> offending part of formatter (located in gluon/dal.py):
>>>>>>
>>>>>> def formatter(self, value):
>>>>>> requires = self.requires
>>>>>> if value is None or not requires:
>>>>>> return value
>>>>>>
>>>>>> If I change the above to:
>>>>>>
>>>>>> def formatter(self, value):
>>>>>> requires = self.requires
>>>>>> if not requires:
>>>>>> return value
>>>>>>
>>>>>> I get my desired behavior, which is to pass "None" to my formatter
>>>>>> which is implemented as part of a custom Validator object. I realize
>>>>>> the
>>>>>> code now has to go "further" for cases where the value is None, but is
>>>>>> it
>>>>>> really safe to assume nobody will ever want to "format" None into
>>>>>> another
>>>>>> string? Not in my case, at least!
>>>>>>
>>>>>> Joe B.
>>>>>>
>>>>>>
>>>>>>
--
