Perl CGI and Template Toolkit

[Perobl]

Hi Monks

I'm trying to create an auto-generated email that will share some data with the recipient. Normally I would pass variables to TT2 using a hash ref and TmplParams:

my $msg = MIME::Lite::TT::HTML -> new(

From => '[e-mail]',
    To => $to,
    Cc => $cc,
    Subject => 'Bid Strategy System - Final Pricing Approval',
    Template => {
        html => 'email_bid_strategy_final_appr.tt',
    },
    TmplOptions => \%options,
    TmplParams => \%mail_params,
);

I can pass most of what I need to pass in %mail_params, however, I'd like to also pass data for a small table. When I pass this to standard HTML, I simply use a HoH.

TT2 EXAMPLE (displaying HoH)

[% FOREACH record IN item_hoh.values.nsort('index') %]
    <tr class="[% loop.parity %]">
    <td>[% record.index %]</td>
        <td>[% record.mva %]</td>
        <td>[% record.hv1 %]</td>
        <td>[% record.hv2 %]</td>
        <td>[% record.ltc %]</td>
        <td>[% record.qty %]</td>
    <tr>
[% END %]

I don't think I can pass a HoH using MIME::Lite::TT::HTML.

Can anyone offer me advice for dealing with a hash and a HoH? Thank you.

[Eliya]

I don't think I can pass a HoH using MIME::Lite::TT::HTML.

Why do you think you can't?  What happens when you try?

[Perobl]

When I try to pass a reference to a HoH, it doesn't recognize it. It doesn't throw an error, but it doesn't display any of the data either.

Also, while a bit vague, the TT2 documentation on CPAN mentions that TmplParams has to be a hash.

It appears that this is an unfortunate limitation in MIME::Lite::TT::HTML. I'd really like to display this data using a table format, but it appears the best I can do is generate a comma delineated text field of the items in the CGI and then pass them in my existing hash.

EDIT

I mean hash reference in the above ... not hash.

[Eliya]

I'm pretty sure you're doing something else wrong.   As you can see below, MIME::Lite::TT::HTML is just passing through the respective hashref to TT2.  And TT2 can certainly handle HoHs (I've done it many times).

$ pwd
/home/eliya/tmp/MIME-Lite-TT-HTML-0.04
$ grep -r TmplParams .
./lib/MIME/Lite/TT/HTML.pm:        TmplParams  => \%params,
./lib/MIME/Lite/TT/HTML.pm:=head2 TmplParams
./lib/MIME/Lite/TT/HTML.pm:    my $tmpl_params = delete $options->{ Tm
+plParams };
$ grep -r '$tmpl_params' .
./lib/MIME/Lite/TT/HTML.pm:    my $tmpl_params = delete $options->{ Tm
+plParams };
./lib/MIME/Lite/TT/HTML.pm:    $tt->process( $template->{html}, $tmpl_
+params, \$html ) or croak $tt->error;
./lib/MIME/Lite/TT/HTML.pm:        $tt->process( $template->{text}, $t
+mpl_params, \$text ) or croak $tt->error;

Could you show the code (with the HoH) you've tried?

[Anonymous Monk]

One rather clever trick is to pass a function.   Specifically, it can be a closure.   (Google it...)   When TT sees a template-variable it is actually smart enough to know when that “variable” is a function-reference and if so it will call that function.   A “closure” can access the local variables of whatever it was contained-in.   It can on-the-fly populate other, “real,” variables that are also referred-to in the template.