>
> The proposal does not work as is. It looks like there is
> no request.vars._formname.
>
How are you entering data into the table? If you are using SQLFORM, there
should always be a hidden _formname field in the form.
> P.S. : There is a small typo : request.vars._formname.startswith(...
>
Oops.
However, with strong inspiration of your solution I made some additonal
> tests and found a compute function that perfectly works :
>
> compute=lambda row: db.t_templates(request.vars.id).f_revision + 1 if (
> request.vars.id and db.t_templates(request.vars.id).f_revision) else 1,
>
>
That should generally work, though I would change it to
if (request.vars.id and db.t_templates(request.vars.id))
Otherwise you'll get an error if the query returns None and you then try to
access the "f_revision" attribute of None. I had originally considered that
simpler approach. The only danger is if for some reason a different form
submission with request.vars.id comes in, and during that request you
happen to insert or update the t_templates table as well -- in that case,
the value inserted into f_revision will likely be based on the wrong
record. I added a check for the _formname to ensure the submitted form is
specifically for the t_templates table.
Anthony
> Super thanks Anthony. I'll use this solution as I prefer to have it on the
> DAL.
>
> Le mardi 1 mai 2012 15:48:06 UTC+2, Anthony a écrit :
>>
>> I think the row object submitted to the compute function only includes
>> the fields that are part of the update, so it won't include
>> row['f_revision']. Instead, you could get the record id from request.vars
>> and use that to query the current value of the f_revision field:
>>
>> db.define_table('t_templates', Field('name'),
>> Field('f_template', 'upload', label=T('File'), notnull=True),
>> Field('f_revision', 'integer', label=T('Revision'),
>> compute=lambda: db.t_templates(request.vars.id).f_revision + 1 if
>> (request.vars.id and
>> request.vars._formname and request.vars_formname.startswith(
>> 't_templates')) else 1))
>>
>> Anthony
>>
>> On Tuesday, May 1, 2012 7:31:43 AM UTC-4, François Delpierre wrote:
>>>
>>> Hi,
>>>
>>> Here is exactly what I would like to have, but it does not compute on
>>> update :
>>>
>>> db.define_table('t_templates',
>>> Field('f_template', type='upload', label=T('File'),notnull=True),
>>>
>>>
>>> Field('f_revision', type='integer', label=T('Revision'),
>>> default=1,
>>> compute=lambda row: row['f_revision']+1 ,
>>> ),
>>> )
>>>
>>>
