Drupal theming for designers, continued.

Drupal Theming – Part 2 – Controlling themes

This is a continuation of the earlier article on Drupal theming for designers.

Near the end of the previous article, we mentioned other *.tpl.php files used by themes. These files, and any others that you create, using Drupal’s PHPTemplate file naming convention, you are able to ‘override’ the default display:

• node.tpl.php
• block.tpl.php
• box.tpl.php
• comment.tpl.php

Drupal’s PHPTemplate theme engine uses the content generated by these files in page.tpl.php, as the following diagram demonstrates:

More control means more power

Using the *.tpl.php you can control:

• the display of different content types, such as blogs, forum posts, or anything else you create. What are 'content types' (node-[content type].tpl.php)
• the display of content in edit-mode (node-edit.tpl.php)
• the display of individual nodesWhat is a 'node' (node-[node ID number].tpl.php)
• the display of the front page

Controlling the content being passed to the *.tpl.php using variables

Let’s look at the variables used in page.tpl.php and node.tpl.php:

Here, we see page.tpl.php prints variables such as $sidebar_left and $mission.

In node.tpl.php we see variables such as $sticky.

You can use template.php to override functions returning these variables and you can intercept other variables:

This template.php example, from the Zen theme, demonstrates function overrides:

• zen_regions
• zen_breadcrumb

Here is the documentation listing all themable functions: http://api.drupal.org/api/group/themeable/5

A brief note regarding regions

It also demonstrates variable re-definition, which is scope controlled:

• $vars[variablename]

Here is documentation listing all variables available in page.tpl.php, node.tpl.php, and block.tpl.php.

For more on creating Drupal themes, I recommend the following:

• http://apress.com/resource/bookfile/3486 (PDF)
• http://11heavens.com/theming-Drupal
• http://drupal.org/node/11811