Magento - Adding breadcrumbs to Homepage

1. Register the new module (we will call the module CMS and give the development company the name Acme):

In your magento\app\etc\modules directory create a file named Acme_All.xml with the following content:-

<?xml version="1.0"?>
<config>
  <modules>
    <Acme_Cms>
      <active>true</active>
      <codePool>local</codePool>
    </Acme_Cms>
  </modules>
</config>

2.  Register the module (which will be implemented in the class
Acme_Cms_Block_Page) as being responsible for rewrite-ing the cms/page
block

In a magento\app\code\local\Acme\Cms\etc directory (you will need to
create it) create a config.xml file with the following content:-

<?xml version="1.0"?>
<config>
  <global>
    <blocks>
      <cms>
        <rewrite>
          <page>Acme_Cms_Block_Page</page>
        </rewrite>
      </cms>
    </blocks>
  </global>
</config>

3. Change the original block logic (based on what is in app\code\core\Mage\Cms\Block\Page.php) to handle our CMS home page.

In a magento\app\code\local\Acme\Cms\Block directory create a file named Page.php with the content:-

<?php class Acme_Cms_Block_Page extends Mage_Cms_Block_Page{
protected function _prepareLayout(){
  $page=$this->getPage();
  //show breadcrumbs
  if(Mage::getStoreConfig('web/default/show_cms_breadcrumbs') && ($breadcrumbs=$this->getLayout()->getBlock('breadcrumbs'))
&& ($page->getIdentifier()!==Mage::getStoreConfig('web/default/cms_no_route'))){
  $breadcrumbs->addCrumb('home',array('label'=>Mage::helper('cms')->__('Home'),'title'=>Mage::helper('cms')->__('Go to Home Page'),'link'=>Mage::getBaseUrl()));
  if ($page->getIdentifier()!==Mage::getStoreConfig('web/default/cms_home_page')){
    $breadcrumbs->addCrumb('cms_page', array('label'=>$page->getTitle(), 'title'=>$page->getTitle()));
  }
}
  if($root=$this->getLayout()->getBlock('root')){
    $root->addBodyClass('cms-'.$page->getIdentifier());
  }
  if($head=$this->getLayout()->getBlock('head')){
    $head->setTitle($page->getTitle());
    $head->setKeywords($page->getMetaKeywords());
    $head->setDescription($page->getMetaDescription());
  }
}
}

Be sure that you have enabled breadcrumbs for CMS pages
[Config->Web->Default Pages->Show breadcrumbs for CMS pages =
Yes]


Reference: http://www.magentocommerce.com/boards/viewthread/49743/