Well, if you're going to be a purist, the proper thing would be to
create a drop-in component subclass of checkbox that only accepted
checked=true input. :-)
But that's overkill. The most simple reusable way to do this is to
create a validator. I have a project, which when eventually
converted to JSF, would need such a validator. Even though it's
simple, I'd say it's a reasonable candidate for the commons validator
project since it's a common use case.
On Wed, Mar 5, 2008 at 3:49 AM, Michael Heß <[EMAIL PROTECTED]> wrote:
> Thanks for you input.
>
> I gave this some more thought on my way home last night. When I think
> about it - is a validator the right place to do this kind of "business
> logic" (e.g. user has checked the box)? Shouldn't validators be all about
> semantics like correct value range or format?
>
> For a thing like "is Checkbox true/false" this is probably a close call,
> especially because the implementation will be minimalistic. But from a
> puristic view I think it would be false to put it in a validator at all.
>
> Any thoughts on this from you?
>
> bye, Michael
>
> [EMAIL PROTECTED] schrieb:
>
>
> > The "required=true" flag means that the user *must supply a value*, but
> > doesn't ensure that they provide a specific value. With a checkbox, the
> > user *always* effectively provides a value: unchecked=false, checked=true.
> >
> > So as Martin says, required=true is in fact pointless for checkboxes.
> > And his recommendation to just use the validator *attribute* on the
> > checkbox component is probably the best, although a custom validator
> > class would also be possible. In either case, it should take about 10
> > lines of code.
> >
> > Cheers, Simon
> >
> > Martin Marinschek schrieb:
> >> Hi Michael,
> >>
> >> you are on the right track - the required==true flag will not help in
> >> the case of the checkbox, as for checkboxes, JSF will _always_ set a
> >> value (either true or false, due to the problems you mentioned above -
> >> there is no way to distinguish between false and value not set at
> >> all...).
> >>
> >> what you can do instead is set the validator="#{myBb.validator}"
> >> attribute and validate in this method accordingly (or, as you said,
> >> write a new validator).
> >>
> >> regards,
> >>
> >> Martin
> >>
> >> On 2/27/08, Michael Heß <[EMAIL PROTECTED]> wrote:
> >>
> >>> Hi List,
> >>>
> >>> now that I have spent several hours trying to figure it out on my own,
> >>> I'm
> >>> giving this list a try.
> >>>
> >>> What I want to do is rather basic: I want to have a mandatory checkbox
> >>> in
> >>> my view. So if the user wants to continue working with the application
> >>> he
> >>> must first tick the box.
> >>>
> >>> So what I came up with was to use the required="true" on the
> >>> h:selectBooleanCheckbox . Unfortunately this does not work. As I tried
> >>> to
> >>> find out what goes wrong I gave h:inputText a try, and it worked as
> >>> expected, i.e. the form was considered invalid as long as the textbox
> >>> was
> >>> empty. So something is fishy about the checkbox...
> >>>
> >>> OK, so I remember back from the struts days, that checkboxes are tricky
> >>> because they do not submit any value at all (not even an empty one)
> >>> when
> >>> unchecked. Searching some more, I found a rather interesting discussion
> >>> in
> >>> http://issues.apache.org/jira/browse/MYFACES-1467. Although the main
> >>> problem is about validators not running, the issue that required="true"
> >>> gets ignored in case the component does not create a http parameter at
> >>> all, is discussed at well. To the end of that issue it first seemed
> >>> like a
> >>> patch was supplied, but then again several problems popped up, and
> >>> someone
> >>> suspects that it's a spec issue.... frankly - i`m at a loss here. :-)
> >>>
> >>> So, what is the right approach for this behaviour? Create a
> >>> "MandatoryCheckboxValidator" and attach it to the checkboxes? Maybe
> >>> someone else had the problem already and can give me a hint how to
> >>> proceed?
> >>>
> >>
> >
> >
> >
>
>
> --
>
>
> Michael Heß
> Senior Consultant
>
> ORDIX AG
> Westernmauer 12-16
> 33098 Paderborn
>
> http://www.ordix.de
> Tel.: 05251 / 10 63 0
> Fax : 05251 / 10 63 99
> Mob : 0163 /673 49 43
>
> ORDIX AG - Aktiengesellschaft für Softwareentwicklung, Schulung, Beratung
> und Systemintegration
> Vorsitzender des Aufsichtsrates: Prof. Dr. Hermann Johannes
> Vorstand: Wolfgang Kögler (Vorsitzender), Benedikt Georgi, Christoph
> Lafeld, Axel Röber
> Firmensitz: Westernmauer 12 - 16, 33098 Paderborn, Tel: 05251 / 1063-0,
> Fax: 0180 / 1 67 34 90
> Amtsgericht Paderborn, HRB 2941, Ust-IdNr.DE 126333767, Steuernummer:
> 339/5866/0142
>
>
>
