Docs are not allways the best part in programming languages, frameworks or CMS. Sometimes you try to make something and you find problems, just because poor documentation.

It's my situation just now. I was trying to create tpl.php files for a module, and it is really easy... if you follow exactly all the steps.

First, hook_menu:

/**

 * Implements hook_menu().

 */

function mymodule_menu() {

$items = array();

/*

* Category reviews section 

*/

$items['reviews'] = array(

'title'             => 'Bounty reviews',

'description'       => 'Show review categories.',

'page callback'     => 'listofProducts',

  'page arguments'    => array('bounty_settings'),

'access callback'   => 'user_access',

'access arguments'  => array('administer site configuration'),

'type'              => MENU_NORMAL_ITEM,

'file'              => 'includes/bounty_reviews.inc',

);

return $items;

}

Secondly, you could think that just creating the listofProducts should be enought. Well, not at all, you need the theme hook, to show the content using the tpl.php of you choose:

/**

 * Implements hook_theme().

 */

function mymodule_theme($existing, $type, $theme, $path){

$path = drupal_get_path('module', 'mymodule'); // . '/templates';

// ADD THE templates DIRECTORY

$path = $path . '/templates'; 

return array(

// as in 'theme('verbose_method',...)

'main_reviews' => array(

'template' => 'main_page_reviews',

'path' => $path,

'variables' => array('forums' => NULL, 'topics' => NULL,'parents' => NULL, 'tid' => NULL, 'sortby' => NULL, 'forum_per_page' => NULL),

),

//...

);

}

And, ending with the magic:

/**

 * List of  reviewable products

 *

 */

function listofProducts(){

$output = theme('list_products');

return $output;

}

That's all. If you forget the _theme hook you can be struggling for hours, just receiving a beauty WSOD (White Screen Of the Death) and no more information.

You wellcome :-).