[Zope] Form Variable

[Asad Habib]

I have a form variable whose value is being passed to a DTML method upon
form submission. In this DTML method, I use the form variable as input to
a <dtml-in>. When this form variable is passed as a list(i.e. it contains
multiple values), everything works fine. However, when this form variable
is passed as a string(i.e. it contains a single value), <dtml-in>
complains that it is being passed an input of the wrong type. Is there a
way to detect whether this form variable is a list or string? Using the
len function doesn't work because len works on both strings and lists.

One solution I have figured out uses a HTML hidden variable to set the
form variable to a default value. This guarantees that the form variable
is always a list since a minimum of 2 values are passed upon form
submission. However, this is a hack and I'd rather use something more
elegant.

Any help would be greatly appreciated. Thanks.

- Asad