While all connector can filter data by url manipulation, only Grid and TreeGrid¹⁾ has native GUI for sorting, so below info mostly actual for those two components.

To enable server side filtering you can use one of the following in-header filter types while configuring dhtmlxGrid:

• #connector_text_filter - searches for values which contain mask defined through text field
• #connector_select_filter - searches for values which contain mask defined through list of possible values

	mygrid.setHeader("Column A, Column B");
	mygrid.attachHeader("#connector_text_filter,#connector_select_filter")

When using text filter, no any additional configuration necessary. Grid will automatically send data about new entered text and filter server side using %mask% pattern. If you need change filtering pattern or implement more advanced logic - beforeFilter server side event can be used

Event receives FilterInterface Object as parameter

Define default filtering

   function custom_filter($filter_by){
          //WHERE some_field LIKE 'value'
          if (!sizeof($filter_by->rules)) 
               $filter_by->add("some_field","value","LIKE");
   }
   $conn->event->attach("beforeFilter","custom_filter");

Redefine default filtering logic

   function custom_filter($filter_by){
          //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");

By using beforeRender events it possible to define filtering rules as PHP code ( will not work for dyn. modes )

function custom_filter($data){
     if ($data->get_value("some")<0)
          $data->skip(); //not include in output
}
$conn->event->attach("beforeRender","custom_filter")

If you are using select filter you may need to define list of options in select box, it can be defined in one of 3 ways

• automatic - if no custom instruction provided , grid will use DISTINCT select against related field, and fetch all possible options
• hardcoded list

	$grid->set_options("item_nm",array("1","two","3"));
	$grid->render_table("grid50","item_id","item_nm,item_cd");

• list created on base of different table

	$filter1 = new OptionsConnector($res);
	$filter1->render_table("countries","country_id","country_name(value)");
	$grid->set_options("item_nm",$filter1);
 
	$grid->render_table("grid50","item_id","item_nm,item_cd");

You can use both render_table and render_sql for OptionsConnector object, same as for any normal connector.

Beware that name of fields, used in select filter need to have alias (value)