Errore Nel Creare Un File Excel Con Tlbexcelview

Salve ragazzi sto cercando di creare un file excel sequendo questo :

http://www.yiiframework.com/extension/tlbexcelview/#hh2

io ho fatto questo:


 private function creaExel($tabella){

   

        $this->widget('application.components.widgets.tlbExcelView', array(

            'id'                   => 'some-grid',

            'dataProvider'         => $tabella,

            'grid_mode'            => 'grid', // Same usage as EExcelView v0.33

            //'template'           => "{summary}\n{items}\n{exportbuttons}\n{pager}",

            'title'                => 'Some title - ' . date('d-m-Y - H-i-s'),

            'creator'              => 'Your Name',

            'subject'              => mb_convert_encoding('Something important with a date in French: ' . utf8_encode(strftime('%e %B %Y')), 'ISO-8859-1', 'UTF-8'),

            'description'          => mb_convert_encoding('Etat de production généré à la demande par l\'administrateur (some text in French).', 'ISO-8859-1', 'UTF-8'),

            'lastModifiedBy'       => 'Some Name',

            'sheetTitle'           => 'Report on ' . date('m-d-Y H-i'),

            'keywords'             => '',

            'category'             => '',

            'landscapeDisplay'     => true, // Default: false

            'A4'                   => true, // Default: false - ie : Letter (PHPExcel default)

            'pageFooterText'       => '&RThis is page no. &P of &N pages', // Default: '&RPage &P of &N'

            'automaticSum'         => true, // Default: false

            'decimalSeparator'     => ',', // Default: '.'

            'thousandsSeparator'   => '.', // Default: ','

            //'displayZeros'       => false,

            //'zeroPlaceholder'    => '-',

            'sumLabel'             => 'Column totals:', // Default: 'Totals'

            'borderColor'          => '00FF00', // Default: '000000'

            'bgColor'              => 'FFFF00', // Default: 'FFFFFF'

            'textColor'            => 'FF0000', // Default: '000000'

            'rowHeight'            => 45, // Default: 15

            'headerBorderColor'    => 'FF0000', // Default: '000000'

            'headerBgColor'        => 'CCCCCC', // Default: 'CCCCCC'

            'headerTextColor'      => '0000FF', // Default: '000000'

            'headerHeight'         => 10, // Default: 20

            'footerBorderColor'    => '0000FF', // Default: '000000'

            'footerBgColor'        => '00FFCC', // Default: 'FFFFCC'

            'footerTextColor'      => 'FF00FF', // Default: '0000FF'

            'footerHeight'         => 50, // Default: 20

            'columns'              =>'N_pratica',                                                                

        )); 

        

    }

dove $tabella è un CActiveDataProvider. il problema è questo:

Fatal error: Call to a member function getData() on a non-object in C:\xampp\htdocs\yii\framework\zii\widgets\CBaseListView.php on line 108

ma non riesco a capirne il motivo

Risolto questo problema era un errore del dataProvider, ma comunque non riesco a capire dove salva il file