[Zope] dtml-if and checkboxes

[Jim Penny]

On Fri, Oct 04, 2002 at 04:51:14PM -0400, Hires, Russell (CAP, CARD) wrote:

I emailled Rusell in a private email, but it may do some good to put it
on the mailing list where others who have not travelled far in the way 
can see this:

> Well, I got one better:
> <dtml-if check_box>
> The check box is checked!
> </dtml-if>

Be very careful with this form.  If at some later date, you are working
and change it to this:

<dtml-if "check_box">
  The check box is checked!
</dtml-if>

then your program will stop working again.  Moreover, since the "simple
form" above will try acquisition if check_box is not found in the
REQUEST, you may have a very hard time debugging boxes that are
unexepectedly checked.

That is why the more explicit

<dtml-if "REQUEST.has_key('check_box')">
  The check box is checked!
</dtml-if>

is much preferable, even though it is a bit more typing.

Same with zpt forms given.  They are, by design, explicit.

Jim Penny


> 
> This works because if it's checked, then it's there. If it isn't checked, it
> isn't there, and it fails. So no output. 
> 
> Thanks for pushing me in the right direction. 
> 
> Russell
>