As book says...
"DAL fields may have a compute attribute. This must be a function (or
lambda) that takes a Row object and returns a value for the field."
So, lambda for computed fields gets all fields and returns just one field.
I think it work on DAL level, not on FORM level.
On 12/19/11, Richard Vézina <ml.richard.vez...@gmail.com> wrote:
> I don't get all my db.table fields form define_table fields defined...
>
> A other guy report that... But didn't find exactly why his compute
> functions as stop working properly...
>
> To me it's related to the fact tha if I do :
>
> Field('mycomputefield', compute=lambda r: r)
>
> I am not getting all the fields.
>
> For example:
>
> db.define_table('test1',
> Field('f1','string'),
> Field('f2','integer'),
> Field('computefield',compute=lambda r: r))
>
> Will return only field that appear in form, so if I set f1 to
> writable=False, it will not be in form so it will not be available to
> compute function...
>
> I think it for make compute failed silently if some fields are set to
> writable or readable = False... But I would return all the field to compute
> with a "None" for empty field instead of not returning any key... I really
> don't know if it even possible, if it is a bug or something else...
>
> I work around issue I were having with compute (I would compute a md5 hash
> for row so I would have all key/value pairs even if one of those were
> empty, but I can't with compute), so I use the new virtual field style
> (hope it will stay).
>
> Here the thread I am refering to :
> http://groups.google.com/group/web2py/browse_thread/thread/cd6191f9827a48d5/a367c0e5055bb676?lnk=gst&q=Computed+Fields+broken+by+1.99.2#a367c0e5055bb676
>
>
> Richard
>
> On Mon, Dec 19, 2011 at 2:22 PM, Anthony <abasta...@gmail.com> wrote:
>
>> What do you mean it doesn't return all the fields?
>>
>>
>> On Monday, December 19, 2011 10:47:42 AM UTC-5, Richard wrote:
>>>
>>> Hello,
>>>
>>> I try to use compute to generate a record md5_hash on insert and
>>> update, but I discover that compute=lambda r: don't return all the
>>> db.table fields why?
>>>
>>> Thanks
>>>
>>> Richard
>>>
>>>
>
