extendedSummary Yiiboster not show the sum total of gridview - yii

Question

I have gridview using TbExtendedGridView yii booster, in footer gridview i want show the sum of field using extendedSummary, i have follow the tutorial in yiibooster web but i can't show the extendedSummary to show the sum of column. Pls help me what's wrong in my code below ?. in the footer just show the box with blank text.
//this isi my gridview code
$no_loan= $_GET[no_loan];
$sql2="SELECT * from tbangsuran where nomor_pinjaman = '$no_loan' and status_bayar=1 order by no ASC";
$sqlProvider = new CSqlDataProvider($sql2);
$this->widget('bootstrap.widgets.TbExtendedGridView', array(
//'filter'=>$model,
'id'=>'tbangsuran-grid',
'type'=>'striped bordered',
'template' => "{items}\n{extendedSummary}",
'dataProvider' =>$sqlProvider,
'columns'=>array(
array(
'name'=>'Angsuran Ke',
'headerHtmlOptions'=>array('style'=>'text-align:center; width:90px;'),
'htmlOptions'=>array('style'=>'text-align:center'
),
'value'=> '$data[\'no\']',
),
array(
'name'=>'Tanggal Tagihan',
'headerHtmlOptions'=>array('style'=>'text-align:center;width:90px;'),
'htmlOptions'=>array('style'=>'text-align:center'),
'value'=> 'date("d-m-Y",strtotime($data[\'tanggal_bayar\']))',
),
//'nomor_pinjaman',
array(
'name'=>'Tunggakan Pokok',
'headerHtmlOptions'=>array('style'=>'text-align:center; width:120px;'),
'htmlOptions'=>array('style'=>'text-align:right'),
'value'=> 'number_format($data[\'pastdue_pokok\'],0,"",".")',
),
array(
'name'=>'Tunggakan Bunga',
'headerHtmlOptions'=>array('style'=>'text-align:center; width:120px;'),
'htmlOptions'=>array('style'=>'text-align:right'),
'value'=> 'number_format($data[\'pastdue_bunga\'],0,"",".")',
),
array(
'name'=>'Total Tunggakan',
'headerHtmlOptions'=>array('style'=>'text-align:center;width:120px;'),
'htmlOptions'=>array('style'=>'text-align:right'),
'value'=> 'number_format($data[\'pastdue_pokok\']+$data[\'pastdue_bunga\'],0,"",".")',
),
),
'extendedSummary' => array(
'title' => 'Total Tunggakan',
'columns' => array(
'pastdue_pokok' => array('label'=>'Total Tunggakan','class'=>'TbSumOperation')
)
),
'extendedSummaryOptions' => array(
'class' => 'well pull-right',
'style' => 'width:300px'
),
));

Answer 1

You must use the same column name in extendedSummary field.
In your case would be:
'extendedSummary' => array(
'title' => 'Total Tunggakan',
'columns' => array(
'Total Tunggakan' => array('label'=>'Total Tunggakan','class'=>'TbSumOperation')
)
),
I recommend you to use short column name to this tasks.
Hope this helps!