Hi,


On Fri, Feb 19, 2010 at 4:48 PM, Christopher Curry <ccurry@amphilsoc.org> wrote:
  

Just to verify, I can call the itemnumber variable with:

<!-- TMPL_VAR NAME="itemnumber" -->

right?
    

Correct, although only in the TMPL_LOOP that goes through the item data.

  

It seems like these variables usually use the MySQL field name, which is
very logical.  Is that a good rule of thumb to follow when determining if a
variable is available to a template?
    

It's a reasonably good rule of thumb, but not a perfect one.

  

Any idea where these variables are
defined?  I have fundamental programming knowledge, but don't know much
about perl.  Thanks for answering the novice questions.
    

Koha uses HTML::Template::Pro for its templating.  Basically, an
HTML::Template::Pro object is created that binds itself to a
particular template, and variables are passed to the template via the
param() method.  get_template_and_user() in C4::Auth is a wrapper
that, among other things, creates the template object, which is
normally referred to as $template in the Perl scripts.

In the simplest case, to pass a scalar value to the template, you
would do something like this:

$template->param(bar => 'value');

In the template, that value would be retrieved using

<!-- TMPL_VAR NAME="bar" -->

You can also pass more complicated data structures.  For example:

$template->param(
  myloop => [
     { value => 'abc' },
     { value => 'def' },
  ],
);

which can be retrieved via

<!-- TMPL_LOOP NAME="myloop" -->
  <!-- TMPL_VAR NAME="value" -->
<!-- /TMPL_LOOP -->

which would emit

abc
def

Regards,

Galen