/**
* Get the active layout handles for this block and any child blocks
*
* This is probably kind of slow since it uses a bunch of xpath searches
* but this was the easiest way to get the info needed. Should be a target
* for future optimization
*
* There is an issue with encoding the used handles in the URL, if the used
* handles change (ex customer logs in), the cached version of the page will
* still have the old handles encoded in it's ESI url. This can lead to
* weirdness like the "Log in" link displaying for already logged in
* visitors on pages that were initially visited by not-logged-in visitors.
* Not sure of a solution for this yet.
*
* Above problem is currently solved by EsiController::_swapCustomerHandles()
* but it would be best to find a more general solution to this.
*
* @param Mage_Core_Block_Template $block
* @return array
*/
protected function _getBlockLayoutHandles($block)
{
Varien_Profiler::start('turpentine::observer::esi::_getBlockLayoutHandles');
$layout = $block->getLayout();
$layoutXml = Mage::helper('turpentine/esi')->getLayoutXml();
$activeHandles = array();
// get the xml node representing the block we're working on (from the
// default handle probably)
$blockNode = current($layout->getNode()->xpath(sprintf('//block[@name=\'%s\']', $block->getNameInLayout())));
$childBlocks = Mage::helper('turpentine/data')->getChildBlockNames($blockNode);
foreach ($childBlocks as $blockName) {
foreach ($layout->getUpdate()->getHandles() as $handle) {
// check if this handle has any block or reference tags that
// refer to this block or a child block, unless the handle name
// is blank
if ($handle !== '' && $layoutXml->xpath(sprintf('//%s//*[@name=\'%s\']', $handle, $blockName))) {
$activeHandles[] = $handle;
}
}
}
if (!$activeHandles) {
$activeHandles[] = 'default';
}
Varien_Profiler::stop('turpentine::observer::esi::_getBlockLayoutHandles');
return array_unique($activeHandles);
}
