Full width template for end level category

Question

I have lots of categories and sub categories for them. For example,

Car is a category Benz, Audi, BMW are its sub categories.

So if the user is in Car category page it will show a small description of Car with a photo, also list all the sub categories of Car after that. Important thing is that this page is two column. In other words, this page have sidebar.

Now if a user comes to Benz category, it shouldn't have that side bar. In other words it should be full width template.

How to achieve this requirement.?

Note : I don't want to set template manually for that category through admin panel. I want to do this automatically. Like if the category don't have any sub category, then full width template should load.

Answer 1

Create an event on controller_action_layout_load_before event
Study Basic magento event observer http://www.solvingmagento.com/events-and-observers-a-magento-tutorial/

on put an condition current fullaction and

add a layouts

public function beforeLoadLayout($observer)
{

$fullAction=$observer->getEvent()->getFullActionName()
if($fullAction=='catalog_category_view'):

$currentCategoryId=  Mage::getSingleton('catalog/layer')->getCurrentCategory()->getId();

$children = Mage::getModel('catalog/category')->getCategories($currentCategoryId);
if(count(count($children)>0)){
       $observer->getEvent()->getLayout()->getUpdate()
       ->addHandle('cat_has_child_cat');
}else{
      $observer->getEvent()->getLayout()->getUpdate()
       ->addHandle('cat_has_no_child_cat');
}
endif;
}

Create local.xml at your lyaout file add below code and set template according to it

<?xml version="1.0"?>
<layout version="0.1.0">
    <cat_has_child_cat translate="label">
        <!-- Mage_Catalog -->
        <reference name="root">
            <action method="setTemplate"><template>page/1column.phtml</template></action>
        </reference>
    </cat_has_child_cat>


    <cat_has_no_child_cat translate="label">
        <!-- Mage_Catalog -->
        <reference name="root">
            <action method="setTemplate"><template>page/2columns-right.phtml</template></action>
        </reference>
    </cat_has_no_child_cat>

</layout>