[totaltec]

You assign things to the list, and take them away.
Templates can assign themselves to lists, and so can PHP classes.

Here is a class adding itself to a list:
* @ListChild (list="center", zone="customer")

And a template:
* @ListChild (list="capost_create_return.form.columns", weight="15")

In both cases you will see these declarations in the commented out section at the top of the file. I prefer to add templates/classes to lists by decorating the class or overriding the original template.

You can also do a lot of heavy lifting right in your main.php file.

To add a class or a template to a list, you wrap the call to the addClassToList() method in a function called runBuildCacheHandler() like this:

    public static function runBuildCacheHandler()
    {
        parent::runBuildCacheHandler();

        \XLite\Core\Layout::getInstance()->addClassToList(
            'XLite\Module\CDev\Bestsellers\View\Bestsellers',
            'sidebar.second',
             array(
                'zone'   => \XLite\Model\ViewList::INTERFACE_CUSTOMER,
                'weight' => 100,
             )
        );

        \XLite\Core\Layout::getInstance()->addTemplateToList(
           'modules/CDev/XMLSitemap/menu.tpl',
           'sidebar.second',
           array(
               'zone'   => \XLite\Model\ViewList::INTERFACE_CUSTOMER,
               'weight' => 100,
           )
        );
    }

You can remove a class from a list, and remove a template from a list in your main.php like this:

    /**
     * Decorator run this method at the end of cache rebuild
     *
     * @return void
     */
    public static function runBuildCacheHandler()
    {
        parent::runBuildCacheHandler();

        \XLite\Core\Layout::getInstance()->removeClassFromList(
            'XLite\View\LanguageSelector\Customer',
            'layout.header.bar.links.newby',
            \XLite\Model\ViewList::INTERFACE_CUSTOMER
        );

        \XLite\Core\Layout::getInstance()->removeTemplateFromLists(
            'layout/main.location.tpl'
        );
    }

You can move classes in lists:

protected static function moveClassesInLists()
    {
        return array(
            'XLite\View\LanguageSelector\Customer' => array(
                array('layout.header.bar.links.logged', 'customer'),
                array('layout.header.magnifico.top.bar', 50, 'customer'),
            ),
        );
    }

Move templates in lists:

protected static function moveTemplatesInLists()
    {   
        $templates_list = array();
        
        $templates_list = array(
            'layout/header.bar.search.tpl' => array(
                array('layout.header.bar', 'customer'),
                array('layout.header.bar', 30, 'customer'),
            ),
            'layout/header.right.tpl' => array(
                array('layout.header', 'customer'),
                array('layout.header', 350, 'customer'),
            ),
        );
        
        return $templates_list;
    }

I took most of these examples from my Magnifico template, but you can see where I originally learned them in XLite\Core\Layout.php