Hi Massimo,
Thanks for trying to help. Perhaps I did not clearly explain the
point.
I hope to add an IS_NOT_EMPTY() constraint to any "list:reference
table_name" field. My previous snippet is copied from web2py book, but
in my real need, that "list:reference" field is not necessary a tag.
So I'm not going to plugin_tagging or plugin_wiki direction. Instead
you can think about a booking system inside a company.
db.define_table('employee', Field('name'))
db.define_table('appointment',
Field('subject', 'string'),
Field('participants', 'list:reference employee'),
)
So I don't need any comma-separated-employee-name UI. In fact the
default widget for list:reference is already great. What I need is
just make sure any appointment will have at least one participant.
Can we somehow hook a IS_NOT_EMPTY() into list:reference 's default
widget? Thanks!
Regards,
Ray (a.k.a. Iceberg)
On Jul 24, 3:16 pm, Massimo Di Pierro <[email protected]>
wrote:
> I understand and what you need to do is a bit more complex than needs
> to be. For this reason we have plugin_tagging and tagging in
> plugin_wiki. Another approach is the following...
>
> class TAGGING:
> def __call__(self,field,value):
> return INPUT(_name='%s_%s' % (field._tablename,field.name),
> _value=', '.join(r.name for r in
> db(db.tag.id.belongs(value or [])).select()),
> requires = self.validate)
> def validate(self,tags):
> names = [x.strip() for x in tags.split(',')]
> ids = [r.id for r in
> db(db.tag.name.belongs(names)).select()]
> if len(ids) < len(names):
> return (ids, "one of the tags is invalid or repeated")
> return (ids,None)
>
> db.define_table('tag',
> Field('name', requires=IS_NOT_EMPTY()), format='%
> (name)s')
> db.define_table('product',
> Field('name', requires=IS_NOT_EMPTY()),
> Field('tags', 'list:reference tag',widget=TAGGING()),)
>
> def testme():
> return {
> 'a': crud.update(db.product, request.args(0)),
> 'b': crud.select(db.product),
> }
>
> The custom TAGGING widget renders the list of IDS as a a list of comma-
> separated names. You can also cache the mapping between ids and tag
> names for speed.
