schooltool-developers team mailing list archive

[Justas <justas@xxxxxx>]

On 01/06/2011 06:13 AM, Alan Elkner wrote:
> Hey Guys,
> <...>
> Justus,
>
> Currently, both the person and the resource demo field edit views use
> the CustomEnumFieldTextWidget for the limit_keys field, a textarea
> widget, but that makes the field free-from which is not what we want.
> We need the widget to be something like the default list widget,
> allowing the user to create a list of select drop-downs, one for each
> limit_key.  In the case of person demos, the select field would
> contain 'students', 'teachers', and 'administrators'.  In the case of
> resource demo fields, the list would be 'resource', 'location', and
> 'equipment'.  Can you point me to code that would help me create the
> custom widget that allows the user to add one or more limit_keys using
> a different Choice field for the person demo field limit_keys from
> that or the resource demo fields?  I tried seeing what happens when I
> comment out the setting of the custom widget
> (fields['limit_keys'].widgetFactory = ...), but that causes it to
> raise a ComponentLookupError with name of u'' and context of None.
  There are few ways to do this.  One would be using a set for 
limit_keys instead of a list:

    foo = zope.schema.Set(
        title=_("Foo set"),
        value_type=Choice(
            title=_(u"Foo"),
            source="schooltool.something.group_vocabulary",
            required=False)
        )

  This will give you a multi-select HTML widget that creates sets with 
desired keys.
  Vocabularies here are good - you can use them to dynamically collect 
the keys.  For example, getUtilitiesFor(IResourceFactoryUtility) yields 
utilities with (translatable) "title" and "__name__" you want.  And you 
can make a schooltool.app.utils.vocabulary out of 
schooltool.group.defaultGroups.  Lots of goodness there :)


  Alternatively - z3c.form also has CheckBoxWidget (not registered by 
default) that uses checkboxes instead of <select>.  You could register 
it roughly like this:

@adapter(
    zope.schema.interfaces.IUnorderedCollection,
    zope.schema.interfaces.IChoice, z3c.form.interfaces.IFormLayer)
@implementer(z3c.form.interfacesIFieldWidget)
def ChoiceSelectFieldCheckboxWidget(field, value_type, request):
    return FieldWidget(field, 
z3c.form.browser.checkbox.CheckBoxWidget(request))

  A minor nuisance is that it's already registered for these 
interfaces, so you'll need a different layer, or just set the 
CheckBoxWidget as the custom widget.

  Or maybe we can override unordered collection widgets for entire 
schooltool.  Personally I like checboxes better than multi-select.

Justas.