XML has extra content

Question

for a plugin we generate an XML output which works on several systems without a problem. One system though adds extra content.

In the related controller we do have the following lines:

$this->getResponse()->setHeader('Content-Type', 'text/xml; charset=utf-8');
$somevars= array('protocol'=>$protocol,'server_name'=> $_SERVER['SERVER_NAME']);
$this->loadLayout()->getLayout()->getBlock('root')->setTemplate('foo/bar.xml.phtml')->setData('somevars',$somevars);

As said, this works on several systems but not on every system it seems. My question now is, what can we do to prevent magento from adding and/or rendering any other content except the content added via the above lines.

I tried unsetBlock, createClock, addBlock, but still seem to have some issues understanding the concept or the correct order.

Any help is appreciated.

Answer 1

It seems like you only render one block and actually do not want to use anything from the default layout handle. In this case it's better to not load the layout from XML at all and instead only create this single block:

$block = Mage::app()->getLayout()
    ->createBlock('core/template')
    ->setTemplate('foo/bar.xml.phtml')->setData('somevars',$somevars);

$this->getResponse()->setBody($block->toHtml());

But it's still possible that there are extensions which manipulate any response with the controller_action_postdispatch event. To prevent this from being fired, you can set a flag:

$this->setFlag('', self::FLAG_NO_POST_DISPATCH);