[Koha-devel] template system abuse

13 Apr 2006

      Hi koha-devel,

Having worked on several intranet template, I've seen things that make
me think we sometimes abuse of the HTML::Template toolkit. Apart from
the pagination bar I added recently, I propose 2 examples:

1. URL creation
===============

We want an URL like the following: "script.pl?key1=value1&key2=value2"

To achieve this, I've seen :

href="<!-- TMPL_VAR NAME="script_name" -->?firstkey=firstval&<!--
TMPL_LOOP NAME="url_params" --><!-- TMPL_VAR NAME="key" -->=<!--
TMPL_VAR NAME="val" -->&<!-- /TMPL_LOOP -->"

(everything on a single line, of course... enjoy the unreadability of
345 characters per line)

I really don't understand what we gain by building the URL in the
template... while we could do this beautifuly in Perl code before
sending to template:

$template->param(
    url =>
        $scriptname.'?'.
        .join(
            '&',
            map { $_->{key}.'='.$_->{val} } @field_data
        ),
);

and in template:

href="<!-- TMPL_VAR NAME="url" -->"

2. "selected" option in SELECT
==============================

Each option of an HTML SELECT can be selected or not. Localization
mecanism forbids to have a TMPL_IF inside the <option> tag. So we need
something like:

<!-- TMPL_LOOP NAME="items" -->
  <!-- TMPL_IF NAME="selected" -->
  <option value="<!-- TMPL_VAR NAME="value" -->" selected="selected"><!-- TMPL_VAR NAME="name" --></option>
  <!-- TMPL_ELSE -->
  <option value="<!-- TMPL_VAR NAME="value" -->"><!-- TMPL_VAR NAME="name" --></option>
  <!-- /TMPL_IF -->
<!-- /TMPL_LOOP -->

The risk of typo is not negligible, the template can become huge with
many options (see
koha/koha-tmpl/intranet-tmpl/prog/en/circ/circulation.tmpl to
understand what I mean). Couldn't we simply have

<!-- TMPL_LOOP NAME="items" -->
  <option value="<!-- TMPL_VAR NAME="value" -->" <!-- TMPL_VAR NAME="selected" -->><!-- TMPL_VAR NAME="name" --></option>
<!-- /TMPL_LOOP -->

With in Perl script:

selected => (condition ? ' selected="selected"' : '')

My conclusion...

In my opinion, template system is useful for customization. The examples
above are no customization, they make templates heavier, less
readable... harder to customize. Do I miss something or do we really
need complicated templates on given examples?

Bye,

-- 
Pierrick LE GALL
INEO media system