That's way better syntax! Great idea!
On Aug 2, 2011, at 2:31 AM, Massimo Di Pierro wrote:
> We need to work on the speed. This can perhaps help the syntax:
>
> db=DAL()
> db.define_table('a',Field('b','integer'))
> for i in range(10):
> db.a.insert(b=i)
>
> def lazy(f):
> def g(self,f=f):
> import copy
> self=copy.copy(self)
> return lambda *a,**b: f(self,*a,**b)
> return g
>
> class Scale:
> @lazy
> def c(self,scale=1):
> return self.a.b*scale
>
> db.a.virtualfields.append(Scale())
> for row in db(db.a).select():
> print row.b, row.c(1), row.c(2), row.c(3)
>
>
>
> On Aug 1, 3:10 pm, Michael Toomim <[email protected]> wrote:
>> Maybe it helps for me to explain my use-case. I mainly use virtual fields as
>> lazy methods, to help traverse related tables. I was actually surprised that
>> lazy evaluation wasn't the default. I noticed a few implications of this:
>> - Large queries are slowed by virtualfields, even if they won't be needed,
>> esp if they query db
>> - My definitions for virtualfields aren't as clean as they could be,
>> because I have many nested "lazy" funcs in the class definition
>> - We can't serialize all objects into session variables
>>
>> So really I'm just using this because it's a nicer notation to call
>> row.otherthing() instead of getotherthing(row). Maybe I really want some
>> different feature here?
>>
>> On Aug 1, 2011, at 5:40 AM, Anthony Bastardi wrote:
>>
>>
>>
>>
>>
>>
>>
>>> Note, after looking at this some more, Massimo recalled that the reason
>>> auth_user virtual fields were excluded from auth.user (and therefore from
>>> saving in the session) is because some virtual fields are objects that
>>> cannot be pickled and therefore cannot be serialized to store in the
>>> session. So, we're thinking of either creating an option to store auth_user
>>> virutual fields in auth.user, or maybe testing to make sure the virtual
>>> fields can be pickled, and excluding them if not.
>>
>>> Anthony
>>
>>> On Mon, Aug 1, 2011 at 5:30 AM, Michael Toomim <[email protected]>
>>> wrote:
>>> Awesome! I did not know there was an issue submission system.
>>
>>> On Jul 30, 2011, at 7:02 AM, Anthony wrote:
>>
>>>> An issue has been submitted, and this should be corrected soon.
>>
>>>> Anthony
>>
>>>> On Friday, July 29, 2011 9:57:30 PM UTC-4, Anthony wrote:
>>>> auth.user is Storage(table_user._filter_fields(user, id=True)). The
>>>> _filter_fields method of the auth_user table only selects actual table
>>>> fields, not virtual fields, so auth.user will not include any virtual
>>>> fields. Perhaps this should be changed.
>>
>>>> Anthony
>>
>>>> On Friday, July 29, 2011 9:05:39 PM UTC-4, Michael Toomim wrote:
>>>> I think I found a bug in virtualfields. I have the following
>>>> controller:
>>
>>>> def posts():
>>>> user = session.auth.user
>>>> n = user.name # returns None
>>
>>>> Where "person" is defined as a virtualfield on user:
>>
>>>> class Users():
>>>> def name(self):
>>>> return self.users.first_name + ' ' + self.users.last_name
>>>> db.users.virtualfields.append(Users())
>>
>>>> The problem is that user.name returns None, because apparently the
>>>> virtualfield isn't loaded into the session variable of user.
>>
>>>> I made this work with the following modification to the controller:
>>
>>>> def posts():
>>>> user = db.users[session.auth.user.id]
>>>> n = user.name # returns the user name correctly!
>>
>>>> I just had to refetch the user from the database.
