yii - How do I apply a CDataColumn filter to my CGridView so it displays only rows with a null-value? -

i have model boolean value, generated table this:

create table receivable (     ...     is_paid integer default null,     ... ) 

you should take notice of possible null value.

i have gii-generated receivable.php-model , simple cgridview, this:

$dataprovider = $model->search(); $dataprovider->pagination = ['pagesize'=>20];  $this->widget('zii.widgets.grid.cgridview', array(     'dataprovider'=>$dataprovider,     'filter'=>$model,     'columns'=>array(         'id',         [             'name'=>'is_paid',             'type'=>'raw',             'value'=>'($data->is_paid==1)?"paid":"";',             'filter'=>['1'=>'paid', '0'=>'0']         ],         'someothercolumn',         ['class'=>'cbuttoncolumn']     ), ); 

it should make sense far? work fine must say, 1 tiny problem - want allow filtering on null values well!

'filter'=>['1'=>'paid', '0'=>'0', null=>'null']  // shows records.  'filter'=>['1'=>'paid', '0'=>'0', ''=>'null']    // shows records. 'filter'=>['1'=>'paid', '<>1'=>'null or zero']   // shows 0-records only.  

well, i'm @ loss. there way can use cdatacolumn.filter allow user filter on null values? (only display rows 'is_paid'==null)

edit: values can 1,0 or null, filter can applied 1 or 0 (or show everything). how can let user display rows null-values only?

any appreciated!

this 1 way can

1.'filter' => array('0' => yii::t('app', 'no'), '1' => yii::t('app', 'yes')), 

or

2.is_paid:boolean 

or

3.'filter' => chtml::listdata(userregistry::model()->findall(), 'id_user_registry', 'firstname' ), 

in above example have values in db table

or

4.'filter' => lookup::items('option'), 

and above example in model have

4. public static function items($type, $code)         {             if(!isset(self::$_items[$type]))                 self::loaditems($type);             return isset(self::$_items[$type][$code]) ? self::$_items[$type][$code] : false;                    }          private static function loaditems($type)         {             self::$_items[$type]=array();             $models=self::model()->findall(array(                 'condition'=>'type=:type',                 'params'=>array(':type'=>$type),                 //'order'=>'position',             ));             foreach($models $model)                 self::$_items[$type][$model->code]=$model->name;         }