Introduction

horae.groupselect provides a grouped Dropdown widget for zope.formlib using the default optgroup elements provided by HTML.

Usage

To use a grouped dropdown widget the previously used Choice field of the schema has to be replaced by a GroupedChoice field provided in horae.groupedselect.field. A GroupedChoice field takes the exactly same parameters as the stock Choice field but additionally an instance of a groups provider (implementing horae.groupedselect.interfaces.IGroups) has to be provided over the parameter groups. The mentioned groups provider converts the vocabulary of the field into a list of groups.

Imagine field to select a country and you would like to group them by region:

from zope import interface, implements
from zope.schema import vocabulary

from horae.groupedselect import field, interfaces

class Country(object):
    def __init__(self, region, country):
        self.region = region
        self.country = country

class CountryGroups(object):
    implements(interfaces.IGroups)

    def groups(self, vocabulary):
        """
        Converts the given vocabulary into a list of groups:

            return (('Group 1', (term1, term2, term3)),
                    ('Group 2', (term6, term5, term6)),)
        """
        groups = {}
        for term in vocabulary:
            if not term.value.region in groups:
                groups[term.value.region] = ()
            groups[term.value.region] = groups[term.value.region] + \
                (term,)
        return groups.items()

class ICountrySelection(interface.Interface):

    country = field.GroupedChoice(
        title = u'Country',
        vocabulary = vocabulary.SimpleVocabulary((
            # ...
            vocabulary.SimpleTerm(
                Country(u'Europe', u'Switzerland'),
                'ch',
                u'Switzerland'
            ),
            vocabulary.SimpleTerm(
                Country(u'Europe', u'Germany'),
                'de',
                u'Germany'
            ),
            vocabulary.SimpleTerm(
                Country(u'Europe', u'Austria'),
                'at',
                u'Austria'
            ),
            vocabulary.SimpleTerm(
                Country(u'Europe', u'France'),
                'fr',
                u'France'
            ),
            # ...
            vocabulary.SimpleTerm(
                Country(u'North America', u'USA'),
                'us',
                u'USA'
            ),
            vocabulary.SimpleTerm(
                Country(u'Europe', u'Canada'),
                'ca',
                u'Canada'
            ),
            # ...
        )),
        groups = CountryGroups()
    )

Dependencies

• zope.schema

• zope.formlib

Changelog