Magento get layout for given page

I'm working on a Magento module where i want to fetch the layout from a frontend page. By frontend page i mean all types of pages, i.e. cms page, category, product, cart, my account, etc.

I've read the excellent magento-nofrills ebook from Alan Storm and i'm using his Commercebug plugin to help me develop my magento site. I've also spent some time on stackoverflow looking for a similair question, please forgive me if i have missed it.

If for example i have a page id or category id, how do i fetch the layout of that frontend page from code run in the backend?

I've been playing with the request and when i run this code in the frontend i can see that the module, controller, layouthandles etc are changed when for instance looking at a catalog page

$request = Mage::app()->getRequest();
$request->setModuleName('cms');
$request->setRouteName('cms');
$request->setControllerName('page');
$request->setActionName('view');
$requ开发者_如何学Cest->setParam('page_id', 6);

But when i inspect the xml from the layout, i can't seem to force magento to show me the xml for (in this example) cms page with id=6:

Mage::app()->getLayout()->getNode()->asXml();

Maybe i'm thinking way too complicated though. I would like to check if a certain page has sidebars, which blocks and elements are shown on the page and in the sidebars (only active blocks, not the ignored ones).

Thanks in advance! Tim

Call loadLayout() before getLayout().

You can check if a block is active in the layout by calling getBlock($block_name):

$left_block = $this->loadLayout()->getLayout()->getBlock('left');

If the block isn't part of the layout (or is ignored) then $left_block will be false. You can use getBlock() in conjunction with getSortedChildren() to see its child blocks:

$this->loadLayout()->getLayout()->getBlock('content')->getSortedChildren();

The above will return a string array of block names within the "content" block. Only names of active blocks will be returned.