Question

How do you access variables in a hash when using Perl’s HTML::Template module?

I’m building the following hash in my Perl code:

# Load success/error flash messages
if ($query->param("submit")) {
  $template->param(
    FLASH => {
      CLASS => "success",
      MESSAGE => "Your cart has been successfully updated!"
    }
  );
}

I’d like to access these variables in my template. To access a regular variable, you do:

<TMPL_VAR NAME=FLASH>

How might I access FLASH[‘CLASS’] in my template?

Answer 1

There’s nothing in the documentation that indicates you can set a parameter as a hashref. The closest to what you want to do is to put the hashref in an arrayref:

$template->param(
    FLASH => [ {
        CLASS => "success",
        MESSAGE => "Your cart has been successfully updated!"
    } ]
);

Then you can access it as:

<TMPL_LOOP NAME=FLASH>
  <TMPL_VAR NAME=CLASS>
  <TMPL_VAR NAME=MESSAGE>
</TMPL_LOOP>

But having an array with a single element might be overkill. An alternative is to get rid of the hashref and flatten the structure:

$template->param(
    FLASH.CLASS   => "success",
    FLASH.MESSAGE => "Your cart has been successfully updated!"
);

...

<TMPL_VAR NAME=FLASH.CLASS>
<TMPL_VAR NAME=FLASH.MESSAGE>