This is a README file for all interested in the templating system used
by Koha.  It contains guidelines ans descriptions, please feel free to
make comments and contributions to this file.

1. Introduction

  The advantage of a templating system is the separation of code and
  design.  It is much easier to read the HTML and get an imagination of
  what it will look like without having it shattered by declarations and
  functions.  And it is also nicer being able to alter some functions
  without worrying about the web design.

  On the other hand, templating stands in contradiction on scripting the
  procedural way; it forces object-oriented programming.

  With templates Koha can be made fully skinnable: we speak of themes,
  and can support different languages.

2. How does it work

  The short version: Instead of printing HTML from your script, you only
  define some template parameters.

  You design your HTML page without code in it, and where you need to
  insert data generated by the script. You can pass this data from the
  template parameters via special tags.

  Indeed, there is a little more to know.

  I recomend reading the documentation to the HTML::Template module.
  You can obtain it from http://www.perldoc.com/cpan/HTML/Template.html

3. How is it implemented in Koha

  Koha uses templates to handle different themes and languages.  In
  the CVS module "koha", there is a subdirectory for the design files:
  koha-tmpl.  This subdirectory can be checked out from CVS as if it
  were a CVS module "koha-tmpl".

  It contains two directories for the OPAC and the intranet templates:
  opac-tmpl and intranet-tmpl.

  Each of this directories reflects the available themes and their
  languages.  The default theme is "default" and the default language is
  "en" (we use the 2-letter abbreviations, en => English, fr => French,
  de => German and so on).

  If you, for example, want to write a template for the OPAC
  part of the "custommade" theme in Polish, it has to go in
  koha-tmpl/opac-tmpl/custommade/pl/template.tmpl.

  The template files will not reside in your web tree. If
  you want to use an image, you have to put this in your web
  tree, which is organized the same way as the template tree
  (koha-html/opac-html/custommade/pl/images/image.gif).

  If you have files (either templates or files in the webspace)
  which are the same for all themes or languages use the
  "all" directory. For example the "background.jpg" image, which
  is the same for all languages within a theme should go in
  koha-html/(intranet|opac)-html/custommade/all/images/background.jpg).

4. How to use it

  Simply add an entry to the systempreferences: name=theme,
  value=nameoftheme.

  If you want your users be able to override your theme settings enter
  name=allowthemeoverride value=customtheme1,customtheme2,... (names of
  themes you want to be allowed) to the preferences.

  For the language you normally don't have to enter anything, the
  preferences of the user's browser will be used.

  If anything is wrong you can specify a languageorder with the
  following entry: name=languageorder value=en,fr,de,es (or whatever
  comma-separated languages you want)

  If you want to specify a directory for the templates you can do so in
  koha.conf with 'templatedirectory=younameit'.

5. Rules and hints

 5.1 For the templates

  - Use absolute paths; relative paths in HTML tags would be relative to
    the script's position and relative paths in <TMPL_INCLUDE> would be
    relative to the template.

  - You don't have to make templates for everything in your custom theme
    or language. If you omit a template in a language, the template of
    next available language is used. (Languages are tried in the order of
    the user's browser settings.)

    If there is no template in the specified language in a theme, a
    different language will be chosen and NOT a different theme.

    If you omit a template in all languages, the template of the default
    theme will be used.

  - Include comments with useful information such as the template's
    location; this simplifies debugging

  - Use the same name for the template and the script (with different
    extensions of course)

 5.2 for the scripts

  - Use meaningful English (abbreviations) as parameter names

  - If you fetch a list of data, pass it completely and let the designer
    decide which data to use.

  - Working with arrays and loops is always better, even if you have
    only three similar rows.

  - Don't let the script generate html and pass the output to the
    template

6. Templating stuff in Koha

  This section is to describe scripts, modules and functions within them
  to handle with themes, languages and other templating stuff.

  If you write something which matches this, please add a brief
  description here (e.g. function calls and return values).

  - function %path = pathtotemplate(%hash) in C4::Output

    Takes a hash with the following keys:

    -template: the name of the template file (e.g. 'mytemplate.tmpl')

    -type: 'opac', 'intranet', 'none' or something you specify, decides
    which directory to lookup; defaults to intranet

      -'opac': /somedirs/opac-tmpl/theme/language/template.tmpl

      -'intranet': /somedirs/intranet-tmpl/theme/language/template.tmpl

      -'none': /somedirs/theme/language/template.tmpl

      -'my own words': /somedirs/my own
      words/theme/language/template.tmpl

      somedirs is 1. the path-parameter if specified 2. the
      templatedirectory in koha.conf, 3. the includes + '/templates', 4.
      the includes

    -theme: you can manually set a theme (e.g. 'customtheme') only if
    'allowthemeoverride' in systempreferences is set

    -language: you can manually set a language (e.g. 'es')

    -path: you can manually set the path to search for templates (e.g.
    '/usr/koha/sometesttemplates')

    You only need to pass the last three parameters if you want to
    override the preferences for some reasons

   Returns:

    - $path{'path'}: the complete+absolute path of the template (e.g.
    '/somedirs.../opac-tmpl/customtheme/es/mytemplate.tmpl')

    - $path{'fondlanguage'}: '1' if the requested template was available
    in the requested language

    - $path{'fondtheme'}: '1' if the requested template was available in
    the requested theme

7. Links

  Do you have good links for the templater?

  The HTML::Template documentation:
  http://www.perldoc.com/cpan/HTML/Template.html


Comments to dnmeid@gmx.de Dorian