The event occurs before data loading and allows to customize filtering of dataset.

$conn->event->attach("beforeFilter",handlerFunc);

Parameters handlerFunc:

• $filter_by - FilterInterface object

Availability:

• Available for Grid, Combo

Sample:

function custom_filter($filter_by){
       if (!sizeof($filter_by->rules)) 
             $filter_by->add("some_field","value","LIKE");
//change WHERE some_field LIKE '%value%' to the WHERE some_field > 'value'
       $index = $filter_by->index("some_field");
       if ($index!==false)  //there is client side input for the filter
             $filter_by->rules[$index]["operation"]=">";
}
$conn->event->attach("beforeFilter","custom_filter");