Re: HTML::Template Interpolation Error?

checkbox_group returns a list! So what HTML::Template gets is:

$html->param(
   rcadd_list                 => "<input type=checkbox ...",
   "<input type=checkbox ..." => "<input type=checkbox ...",
   "<input type=checkbox ..." => ...
);
[download]

This causes an HTML::Template error when die_on_bad_params is set. Either use join "" => checkbox_group(...) or force scalar context (with scalar or with concatenation as you did above) to get what you want.

blokhead

Comment on Re: HTML::Template Interpolation Error? Select or Download Code

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Re^2: HTML::Template Interpolation Error? by hbo (Monk) on Aug 16, 2004 at 21:26 UTC
Bingo, I think! So, why does ''.checkbox_group(.. flatten the list? Is `"some string".('a','list','of','strings');` [download] equivilant to `"some string".'a'.'list'.'of'.'strings';` [download] ? `"Even if you are on the right track, you'll get run over if you just sit there." - Will Rogers`	[reply] [d/l] [select]
Re^3: HTML::Template Interpolation Error? by blokhead (Monsignor) on Aug 16, 2004 at 21:35 UTC
No, it's because the author of CGI.pm wrote it to do so: `sub checkbox_group { ... return wantarray ? @elements : join(' ',@elements) ... }` [download] A list in scalar context (as in your example directly above) returns the last element of the list (your expression evaluates to "some stringstrings"). For a function, if you want different behavior (as in checkbox_group), you check for scalar or list context with wantarray and return the appropriate thing manually. The CGI docs could probably do a better job making this obvious, though. Perhaps there's a blanket statement somewhere about all HTML-generation functions having this behavior in scalar context? blokhead	[reply] [d/l]
Re^4: HTML::Template Interpolation Error? by hbo (Monk) on Aug 16, 2004 at 21:48 UTC
Got it. So the `''.checkbox_group(...` construct imposed scalar context, which returned something HTML::Template::param() could deal with. Thanks for the education! `"Even if you are on the right track, you'll get run over if you just sit there." - Will Rogers`	[reply] [d/l]