Call to a member function append()

Question

I am getting an error

Call to a member function append()....Mage/Adminhtml/Controller/Action.php on line 122 . I have worked out it is down to my indexAction in the controller

public function indexAction()
{
    $this->_addContent($this->getLayout()->createBlock('prefs/adminhtml_forms'));
    $this->renderLayout();
}

So I have taken a look at the origin of the error

protected function _addContent(Mage_Core_Block_Abstract $block)
{
    $this->getLayout()->getBlock('content')->append($block);
    return $this;
}

I see it requires a block that has to be Mage_Core_Block_Abstract and the block I am calling is Mage_Adminhtml_block_Widget_Grid_Container, however digging down I find Mage_Core_Block_Abstract is the being extended.

enter image description here

So I'm now left with the question, what have I done wrong and how do I resolve it?

class Ps_Prefs_Block_Adminhtml_Forms
extends Mage_Adminhtml_block_Widget_Grid_Container
{
public function _construct()
{
    $this->_controller = 'adminhtml_forms';//path to block
    $this->_blockGroup = 'prefs';//module name
    $this->_headerText = $this->__( 'Form Fields' );
    $this->_addButtonLabel = $this->__( 'New Field' );
    parent::_construct();
}

protected function _prepareLayout()
{
    $this->setChild( 'grid',
            $this->getLayout()->createBlock( $this->_blockGroup . '/' . $this->_controller . '_grid',
            $this->_controller . '.grid' )->setSaveParametersInSession( TRUE ) );
    return parent::_prepareLayout();
}
}

score 5 · Accepted Answer · answered Oct 29 '13 at 10:09

You need to add this line

$this->loadLayout();

before

$this->_addContent($this->getLayout()->createBlock('prefs/adminhtml_forms'));

In your case the layout is not loaded and there is no block with the name content. That's why

$this->getLayout()->getBlock('content')

returns null and you cannot call null->append().

Call to a member function append()

1 Answers1