blank admin grid area

Question

I am trying to add a grid to the admin area, but I am receiving a blank content area (although the wrapper is displaying i.e. the _headerText and _addButtonLabel, the grid itself does not display). I have checked an re checked my code (error reporting is on but I get no errors).

I have tried

$mod = Mage::getModel('prefs/prefsformelements')->getData();
var_dump($mod);

and it tells me the data array is is empty (if there was a problem with the model, surely there would be an error returned?) is there something wrong with my code which for block? (I have provided the code for the grid as I would expect to get an empty grid if there is no data being received).

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

.

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();
}
}

.

class Ps_Prefs_Block_Adminhtml_Forms_Grid
extends Mage_Adminhtml_Block_Widget_Grid
{
public function _construct()
{
    parent::_construct();
    $this->setId('prefs_adminforms_index');
    $this->setDefaultSort('fieldname');
    $this->setDefaultDir('ASC');
    $this->setSaveParametersInSession(TRUE);
    $this->setUseAjax(TRUE);

}

protected function _prepareCollection()
{
    $collection = Mage::getModel('prefs/prefsformelements')->getCollection();
    $this->setCollection($collection);
    return parent::_prepareCollection();
}

protected function _prepareColumns()
{
    $this->addColumn('fieldname', array(
       'header'  =>  $this->__('fieldname'),
       'index'   => 'fieldname'
    ));

    $this->addColumn('idform_elements', array(
        'header'    =>  $this->__('ID'),
        'align'     => 'left',
        'width'     => '50px',
        'index'     => 'idform_elements',//name of db column
    ));

    parent::_prepareColumns();
}

===

EDIT

===

this is the second page that I am trying to a grid to within this module. When I pull the data from the database for grid one I use

$this->_init('prefs/prefs');

but for this model ive been forced to use

$this->_init('ps_prefs/prefsformelements');

without the namespace I get a cant find entity config error, could this have an affect on my current problem?

===

EDIT

===

Still trying to track down the problem and I have found that if I add a simple echo command to Ps_Prefs_Block_Adminhtml_Forms_Grid::_prepareColumns() it is displayed. So would I be right in assuming I have done something wrong with the $this->addColumn commands? or is there something else going on here?

Answer 1

You've asked question with multiple possible answers, dependent on a level of site configuration that's hard to debug remotely.

I usually debug this things bottom up. It looks like you're trying to add block to main content area in the admin interface.

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

So, the first two things I'd check are

• Can I add a text block to the content area

• Can I instantiate my block

The answers to these questions will move you along to the next step of your debugging workflow.

Re: adding a text block -- test that with the following

$this->_addContent(
    $this->getLayout()->createBlock('core/text')->setText('<h1>Success</h1>')
);

You should see the word Success output to the content area.

Re: instantiating your block, test that with

$my_block = $this->getLayout()->createBlock('prefs/adminhtml_forms');
var_dump(get_class($my_block));

You should see your block's class name output to the screen. My guess is you'll see a boolean false for the later, pointing to a misconfigured block and/or a class with the wrong name/location.

Answer 2

A quick one to check is if the module's output has been disabled under System > Configuration > Advanced > Disable Modules Output. If it is disabled for your module it will render a complete page with no errors and just empty where the grid should have been.

Answer 3

I just came across this issue. My problem was bad config.xml tag structure, if:

<models>
    <mycompany_ordergrid>
            <class>Mycompany_OrderGrid_Model</class>
    </mycompany_ordergrid>
    <sales_resource>
        <rewrite>
            <order_grid_collection>Mycompany_OrderGrid_Model_Resource_Sales_Order_Grid_Collection</order_grid_collection>
        </rewrite>
    </sales_resource>
</models>

Is changed to:

<models>
    <mycompany_ordergrid>
            <class>Mycompany_OrderGrid_Model</class>
    </mycompany_ordergrid>
    <sales_resource>
        <rewrite>
            <order_grid_collection>Mycompany_OrderGrid_Model_Resource_Sales_Order_Grid_Collection
            </order_grid_collection>
        </rewrite>
    </sales_resource>
</models>

The order grid will silently fail to load.