[whatwg] forms-lite testbed
Matthew Raymond
mattraymond at earthlink.net
Mon Oct 30 16:32:58 PST 2006
Lachlan Hunt wrote:
> Actually, conditionally required fields would be a very nice addition.
> I built this site earlier this year, which has conditionally required
> fields.
>
> https://www.edentiti.com/create/details.jsf
>
> See the Postal Address section. It's required unless it's the same as
> the residential address. If you check the "Use residential address"
> checkbox, the fields are no longer required. If you uncheck it again,
> they are. The JS updates the fields as soon as you check or uncheck the
> box.
In the case you listed, the scripting is minimal. You would use
something like this:
| <input [...] onforminput="required=!use_res.checked">
The equivalent in Forms-Lite would be this:
| <input [...] needed="use_res = false">
While the formula in the latter is easier to understand for
beginners, scripting is more flexible:
| <input [...] onforminput=
| "required=!use_res.checked; disabled=use_res.checked;">
You could turn any binary attribute into one that takes a formula. I
just don't see a clear advantage in it. In the best cases, you're just
creating a new, simpler scripting language. In the worst case scenario,
you end up implementing something like |onformchange| or |onforminput|
anyways due to the limitations of the formulas.
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