Well, answering my own question, I've managed to get it to work with
GAE with a kinda bizarre data juggling:
The helper function that returns the form element to be inserted into
the SQLFORM is now like this:
def gae_subject_biased_dropdown(teacher_id):
subjects = db(db.subjects.id>0).select(db.subjects.id,
db.subjects.code)
teachers_subjects =
db(db.teachers_subjects.id>0).select(db.teachers_subjects.subject_id,
db.teachers_subjects.teacher_id).as_list()
results = []
for subj in subjects:
if {'teacher_id': int(teacher_id), 'subject_id': subj.id} in
teachers_subjects:
results.append([subj.id, subj.code, 1])
else:
results.append([subj.id, subj.code, 0])
key = [res[0] for res in sorted(results, key=lambda x: x[2],
reverse=True)]
value = [res[1] for res in sorted(results, key=lambda x: x[2],
reverse=True)]
form = SQLFORM.factory(
Field('subject_id', label="Subject",
requires=IS_IN_SET(key, value,
zero=None)))
return form[0][0]
On Oct 12, 1:15 am, Tiago Rosa <[email protected]> wrote:
> An even deeper problem: how to do something like that in a GAE
> environment? The BigTable-like datastore has a lot of query
> restrictions.
>
> On Oct 6, 9:25 pm, Tiago Rosa <[email protected]> wrote:
>
> > Hello annet and Massimo!
>
> > Thank you very much for your help! I still need some enlightenment
> > though =)
>
> > I've managed to make it work thanks to annet's tip. Here's how I am
> > currently doing it:
>
> > I have defined a helper function that takes a teacher_id and spits out
> > the dropdown field (!) generated through annet's method:
>
> > def subject_biased_dropdown(teacher_id):
> > rows = db().select(db.subjects.id, db.subjects.code,
> > left = db.teachers_subjects.on(
> > (db.subjects.id==db.teachers_subjects.subject_id)&
> > (db.teachers_subjects.teacher_id==teacher_id)),
> > orderby=db.teachers_subjects.teacher_id|db.subjects.id)
> > key = [row.id for row in rows]
> > value = [row.name for row in rows]
> > form = SQLFORM.factory(
> > Field('subject_id', requires=IS_IN_SET(key,value,zero=None)))
> > return form[0][0]
>
> > And then, in the "evaluation/create" function of the "evaluation"
> > controller, I replace the dropdown field in the autogenerated SQLFORM
> > with the "biased" one that comes from the above function:
>
> > def create():
> > (...)
> > form_add=SQLFORM(db.evaluations,
> > (...)
> > )
> > form_add[0][0] = subject_biased_dropdown(prof_id)
> > if form_add.accepts(request.vars, session):
> > (...)
> > return dict(form=form_add)
>
> > Yes, it works, but I feel something strange about the way I'm
> > implementing this. I guess I'm missing something obvious that would
> > make it easier/more "best-practice-like". Defining the orderby at the
> > model level seems like a better option, but I can't figure it out yet.
>
> > Again, thank you very much for your help!
>
> > Regards,
>
> > Tiago Rosa
>
> > On Oct 6, 2:01 pm, annet <[email protected]> wrote:
>
> > > Massimo,
>
> > > > you can pass orderby to IS_IN_DB
>
> > > To which IS_IN_DB do I have to pass the orderby to get the same
> > > result. The resultset reads like:
>
> > > 1 1 a
> > > 1 4 d
> > > 1 7 9
> > > None 2 b
> > > None 3 c
> > > None 5 e
> > > None 6 f
>
> > > The orderby: orderby=~db.teachers_subjects.teacher_id|db.subjects.id
> > > first sorts it in reverse order by db.teachers_subjects.teacher_id and
> > > then by db.subjects.id, to meet Tiago's requirement:
>
> > > When creating a new evaluation for teacher t1, the items on the
> > > subject dropdown should appear in the following order:
>
> > > a //related
> > > d //related
> > > g //related
> > > b
> > > c
> > > e
> > > f
>
> > > Annet.
>
>
